1 /*
2  * Cogl
3  *
4  * A Low Level GPU Graphics and Utilities API
5  *
6  * Copyright (C) 2007,2008,2009,2011 Intel Corporation.
7  * Copyright (C) 2019 DisplayLink (UK) Ltd.
8  *
9  * Permission is hereby granted, free of charge, to any person
10  * obtaining a copy of this software and associated documentation
11  * files (the "Software"), to deal in the Software without
12  * restriction, including without limitation the rights to use, copy,
13  * modify, merge, publish, distribute, sublicense, and/or sell copies
14  * of the Software, and to permit persons to whom the Software is
15  * furnished to do so, subject to the following conditions:
16  *
17  * The above copyright notice and this permission notice shall be
18  * included in all copies or substantial portions of the Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
24  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
25  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
26  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
27  * SOFTWARE.
28  *
29  *
30  *
31  * Authors:
32  *   Robert Bragg <robert@linux.intel.com>
33  */
34 
35 #ifndef __COGL_FRAMEBUFFER_H
36 #define __COGL_FRAMEBUFFER_H
37 
38 
39 #include <cogl/cogl-pipeline.h>
40 #include <cogl/cogl-indices.h>
41 #include <cogl/cogl-bitmap.h>
42 #include <cogl/cogl-texture.h>
43 #include <glib-object.h>
44 #include <cairo.h>
45 
46 #include <graphene.h>
47 
48 G_BEGIN_DECLS
49 
50 /**
51  * SECTION:cogl-framebuffer
52  * @short_description: A common interface for manipulating framebuffers
53  *
54  * Framebuffers are a collection of buffers that can be rendered too.
55  * A framebuffer may be comprised of one or more color buffers, an
56  * optional depth buffer and an optional stencil buffer. Other
57  * configuration parameters are associated with framebuffers too such
58  * as whether the framebuffer supports multi-sampling (an anti-aliasing
59  * technique) or dithering.
60  *
61  * There are two kinds of framebuffer in Cogl, #CoglOnscreen
62  * framebuffers and #CoglOffscreen framebuffers. As the names imply
63  * offscreen framebuffers are for rendering something offscreen
64  * (perhaps to a texture which is bound as one of the color buffers).
65  * The exact semantics of onscreen framebuffers depends on the window
66  * system backend that you are using, but typically you can expect
67  * rendering to a #CoglOnscreen framebuffer will be immediately
68  * visible to the user.
69  *
70  * If you want to create a new framebuffer then you should start by
71  * looking at the #CoglOnscreen and #CoglOffscreen constructor
72  * functions, such as cogl_offscreen_new_with_texture() or
73  * cogl_onscreen_new(). The #CoglFramebuffer interface deals with
74  * all aspects that are common between those two types of framebuffer.
75  *
76  * Setup of a new CoglFramebuffer happens in two stages. There is a
77  * configuration stage where you specify all the options and ancillary
78  * buffers you want associated with your framebuffer and then when you
79  * are happy with the configuration you can "allocate" the framebuffer
80  * using cogl_framebuffer_allocate(). Technically explicitly calling
81  * cogl_framebuffer_allocate() is optional for convenience and the
82  * framebuffer will automatically be allocated when you first try to
83  * draw to it, but if you do the allocation manually then you can
84  * also catch any possible errors that may arise from your
85  * configuration.
86  */
87 
88 typedef struct _CoglFramebufferDriverConfig CoglFramebufferDriverConfig;
89 
90 #define COGL_TYPE_FRAMEBUFFER (cogl_framebuffer_get_type ())
91 COGL_EXPORT
92 G_DECLARE_DERIVABLE_TYPE (CoglFramebuffer, cogl_framebuffer,
93                           COGL, FRAMEBUFFER, GObject)
94 
95 struct _CoglFramebufferClass
96 {
97   /*< private >*/
98   GObjectClass parent_class;
99 
100   gboolean (* allocate) (CoglFramebuffer  *framebuffer,
101                          GError          **error);
102   gboolean (* is_y_flipped) (CoglFramebuffer *framebuffer);
103 };
104 
105 /**
106  * cogl_framebuffer_allocate:
107  * @framebuffer: A #CoglFramebuffer
108  * @error: A pointer to a #GError for returning exceptions.
109  *
110  * Explicitly allocates a configured #CoglFramebuffer allowing developers to
111  * check and handle any errors that might arise from an unsupported
112  * configuration so that fallback configurations may be tried.
113  *
114  * <note>Many applications don't support any fallback options at least when
115  * they are initially developed and in that case the don't need to use this API
116  * since Cogl will automatically allocate a framebuffer when it first gets
117  * used.  The disadvantage of relying on automatic allocation is that the
118  * program will abort with an error message if there is an error during
119  * automatic allocation.</note>
120  *
121  * Return value: %TRUE if there were no error allocating the framebuffer, else %FALSE.
122  * Since: 1.8
123  * Stability: unstable
124  */
125 COGL_EXPORT gboolean
126 cogl_framebuffer_allocate (CoglFramebuffer *framebuffer,
127                            GError **error);
128 
129 /**
130  * cogl_framebuffer_get_width:
131  * @framebuffer: A #CoglFramebuffer
132  *
133  * Queries the current width of the given @framebuffer.
134  *
135  * Return value: The width of @framebuffer.
136  * Since: 1.8
137  * Stability: unstable
138  */
139 COGL_EXPORT int
140 cogl_framebuffer_get_width (CoglFramebuffer *framebuffer);
141 
142 /**
143  * cogl_framebuffer_get_height:
144  * @framebuffer: A #CoglFramebuffer
145  *
146  * Queries the current height of the given @framebuffer.
147  *
148  * Return value: The height of @framebuffer.
149  * Since: 1.8
150  * Stability: unstable
151  */
152 COGL_EXPORT int
153 cogl_framebuffer_get_height (CoglFramebuffer *framebuffer);
154 
155 /**
156  * cogl_framebuffer_set_viewport:
157  * @framebuffer: A #CoglFramebuffer
158  * @x: The top-left x coordinate of the viewport origin (only integers
159  *     supported currently)
160  * @y: The top-left y coordinate of the viewport origin (only integers
161  *     supported currently)
162  * @width: The width of the viewport (only integers supported currently)
163  * @height: The height of the viewport (only integers supported currently)
164  *
165  * Defines a scale and offset for everything rendered relative to the
166  * top-left of the destination framebuffer.
167  *
168  * By default the viewport has an origin of (0,0) and width and height
169  * that match the framebuffer's size. Assuming a default projection and
170  * modelview matrix then you could translate the contents of a window
171  * down and right by leaving the viewport size unchanged by moving the
172  * offset to (10,10). The viewport coordinates are measured in pixels.
173  * If you left the x and y origin as (0,0) you could scale the windows
174  * contents down by specify and width and height that's half the real
175  * size of the framebuffer.
176  *
177  * <note>Although the function takes floating point arguments, existing
178  * drivers only allow the use of integer values. In the future floating
179  * point values will be exposed via a checkable feature.</note>
180  *
181  * Since: 1.8
182  * Stability: unstable
183  */
184 COGL_EXPORT void
185 cogl_framebuffer_set_viewport (CoglFramebuffer *framebuffer,
186                                float x,
187                                float y,
188                                float width,
189                                float height);
190 
191 /**
192  * cogl_framebuffer_get_viewport_x:
193  * @framebuffer: A #CoglFramebuffer
194  *
195  * Queries the x coordinate of the viewport origin as set using cogl_framebuffer_set_viewport()
196  * or the default value which is 0.
197  *
198  * Return value: The x coordinate of the viewport origin.
199  * Since: 1.8
200  * Stability: unstable
201  */
202 COGL_EXPORT float
203 cogl_framebuffer_get_viewport_x (CoglFramebuffer *framebuffer);
204 
205 /**
206  * cogl_framebuffer_get_viewport_y:
207  * @framebuffer: A #CoglFramebuffer
208  *
209  * Queries the y coordinate of the viewport origin as set using cogl_framebuffer_set_viewport()
210  * or the default value which is 0.
211  *
212  * Return value: The y coordinate of the viewport origin.
213  * Since: 1.8
214  * Stability: unstable
215  */
216 COGL_EXPORT float
217 cogl_framebuffer_get_viewport_y (CoglFramebuffer *framebuffer);
218 
219 /**
220  * cogl_framebuffer_get_viewport_width:
221  * @framebuffer: A #CoglFramebuffer
222  *
223  * Queries the width of the viewport as set using cogl_framebuffer_set_viewport()
224  * or the default value which is the width of the framebuffer.
225  *
226  * Return value: The width of the viewport.
227  * Since: 1.8
228  * Stability: unstable
229  */
230 COGL_EXPORT float
231 cogl_framebuffer_get_viewport_width (CoglFramebuffer *framebuffer);
232 
233 /**
234  * cogl_framebuffer_get_viewport_height:
235  * @framebuffer: A #CoglFramebuffer
236  *
237  * Queries the height of the viewport as set using cogl_framebuffer_set_viewport()
238  * or the default value which is the height of the framebuffer.
239  *
240  * Return value: The height of the viewport.
241  * Since: 1.8
242  * Stability: unstable
243  */
244 COGL_EXPORT float
245 cogl_framebuffer_get_viewport_height (CoglFramebuffer *framebuffer);
246 
247 /**
248  * cogl_framebuffer_get_viewport4fv:
249  * @framebuffer: A #CoglFramebuffer
250  * @viewport: (out caller-allocates) (array fixed-size=4): A pointer to an
251  *            array of 4 floats to receive the (x, y, width, height)
252  *            components of the current viewport.
253  *
254  * Queries the x, y, width and height components of the current viewport as set
255  * using cogl_framebuffer_set_viewport() or the default values which are 0, 0,
256  * framebuffer_width and framebuffer_height.  The values are written into the
257  * given @viewport array.
258  *
259  * Since: 1.8
260  * Stability: unstable
261  */
262 COGL_EXPORT void
263 cogl_framebuffer_get_viewport4fv (CoglFramebuffer *framebuffer,
264                                   float *viewport);
265 
266 /**
267  * cogl_framebuffer_push_matrix:
268  * @framebuffer: A #CoglFramebuffer pointer
269  *
270  * Copies the current model-view matrix onto the matrix stack. The matrix
271  * can later be restored with cogl_framebuffer_pop_matrix().
272  *
273  * Since: 1.10
274  */
275 COGL_EXPORT void
276 cogl_framebuffer_push_matrix (CoglFramebuffer *framebuffer);
277 
278 /**
279  * cogl_framebuffer_pop_matrix:
280  * @framebuffer: A #CoglFramebuffer pointer
281  *
282  * Restores the model-view matrix on the top of the matrix stack.
283  *
284  * Since: 1.10
285  */
286 COGL_EXPORT void
287 cogl_framebuffer_pop_matrix (CoglFramebuffer *framebuffer);
288 
289 /**
290  * cogl_framebuffer_identity_matrix:
291  * @framebuffer: A #CoglFramebuffer pointer
292  *
293  * Resets the current model-view matrix to the identity matrix.
294  *
295  * Since: 1.10
296  * Stability: unstable
297  */
298 COGL_EXPORT void
299 cogl_framebuffer_identity_matrix (CoglFramebuffer *framebuffer);
300 
301 /**
302  * cogl_framebuffer_scale:
303  * @framebuffer: A #CoglFramebuffer pointer
304  * @x: Amount to scale along the x-axis
305  * @y: Amount to scale along the y-axis
306  * @z: Amount to scale along the z-axis
307  *
308  * Multiplies the current model-view matrix by one that scales the x,
309  * y and z axes by the given values.
310  *
311  * Since: 1.10
312  * Stability: unstable
313  */
314 COGL_EXPORT void
315 cogl_framebuffer_scale (CoglFramebuffer *framebuffer,
316                         float x,
317                         float y,
318                         float z);
319 
320 /**
321  * cogl_framebuffer_translate:
322  * @framebuffer: A #CoglFramebuffer pointer
323  * @x: Distance to translate along the x-axis
324  * @y: Distance to translate along the y-axis
325  * @z: Distance to translate along the z-axis
326  *
327  * Multiplies the current model-view matrix by one that translates the
328  * model along all three axes according to the given values.
329  *
330  * Since: 1.10
331  * Stability: unstable
332  */
333 COGL_EXPORT void
334 cogl_framebuffer_translate (CoglFramebuffer *framebuffer,
335                             float x,
336                             float y,
337                             float z);
338 
339 /**
340  * cogl_framebuffer_rotate:
341  * @framebuffer: A #CoglFramebuffer pointer
342  * @angle: Angle in degrees to rotate.
343  * @x: X-component of vertex to rotate around.
344  * @y: Y-component of vertex to rotate around.
345  * @z: Z-component of vertex to rotate around.
346  *
347  * Multiplies the current model-view matrix by one that rotates the
348  * model around the axis-vector specified by @x, @y and @z. The
349  * rotation follows the right-hand thumb rule so for example rotating
350  * by 10 degrees about the axis-vector (0, 0, 1) causes a small
351  * counter-clockwise rotation.
352  *
353  * Since: 1.10
354  * Stability: unstable
355  */
356 COGL_EXPORT void
357 cogl_framebuffer_rotate (CoglFramebuffer *framebuffer,
358                          float angle,
359                          float x,
360                          float y,
361                          float z);
362 
363 /**
364  * cogl_framebuffer_rotate_euler:
365  * @framebuffer: A #CoglFramebuffer pointer
366  * @euler: A #graphene_euler_t
367  *
368  * Multiplies the current model-view matrix by one that rotates
369  * according to the rotation described by @euler.
370  *
371  * Since: 2.0
372  * Stability: unstable
373  */
374 COGL_EXPORT void
375 cogl_framebuffer_rotate_euler (CoglFramebuffer *framebuffer,
376                                const graphene_euler_t *euler);
377 
378 /**
379  * cogl_framebuffer_transform:
380  * @framebuffer: A #CoglFramebuffer pointer
381  * @matrix: the matrix to multiply with the current model-view
382  *
383  * Multiplies the current model-view matrix by the given matrix.
384  *
385  * Since: 1.10
386  * Stability: unstable
387  */
388 COGL_EXPORT void
389 cogl_framebuffer_transform (CoglFramebuffer         *framebuffer,
390                             const graphene_matrix_t *matrix);
391 
392 /**
393  * cogl_framebuffer_get_modelview_matrix:
394  * @framebuffer: A #CoglFramebuffer pointer
395  * @matrix: (out): return location for the model-view matrix
396  *
397  * Stores the current model-view matrix in @matrix.
398  *
399  * Since: 1.10
400  * Stability: unstable
401  */
402 COGL_EXPORT void
403 cogl_framebuffer_get_modelview_matrix (CoglFramebuffer   *framebuffer,
404                                        graphene_matrix_t *matrix);
405 
406 /**
407  * cogl_framebuffer_set_modelview_matrix:
408  * @framebuffer: A #CoglFramebuffer pointer
409  * @matrix: the new model-view matrix
410  *
411  * Sets @matrix as the new model-view matrix.
412  *
413  * Since: 1.10
414  * Stability: unstable
415  */
416 COGL_EXPORT void
417 cogl_framebuffer_set_modelview_matrix (CoglFramebuffer         *framebuffer,
418                                        const graphene_matrix_t *matrix);
419 
420 /**
421  * cogl_framebuffer_perspective:
422  * @framebuffer: A #CoglFramebuffer pointer
423  * @fov_y: Vertical field of view angle in degrees.
424  * @aspect: The (width over height) aspect ratio for display
425  * @z_near: The distance to the near clipping plane (Must be positive,
426  *   and must not be 0)
427  * @z_far: The distance to the far clipping plane (Must be positive)
428  *
429  * Replaces the current projection matrix with a perspective matrix
430  * based on the provided values.
431  *
432  * <note>You should be careful not to have to great a @z_far / @z_near
433  * ratio since that will reduce the effectiveness of depth testing
434  * since there won't be enough precision to identify the depth of
435  * objects near to each other.</note>
436  *
437  * Since: 1.10
438  * Stability: unstable
439  */
440 COGL_EXPORT void
441 cogl_framebuffer_perspective (CoglFramebuffer *framebuffer,
442                               float fov_y,
443                               float aspect,
444                               float z_near,
445                               float z_far);
446 
447 /**
448  * cogl_framebuffer_frustum:
449  * @framebuffer: A #CoglFramebuffer pointer
450  * @left: X position of the left clipping plane where it
451  *   intersects the near clipping plane
452  * @right: X position of the right clipping plane where it
453  *   intersects the near clipping plane
454  * @bottom: Y position of the bottom clipping plane where it
455  *   intersects the near clipping plane
456  * @top: Y position of the top clipping plane where it intersects
457  *   the near clipping plane
458  * @z_near: The distance to the near clipping plane (Must be positive)
459  * @z_far: The distance to the far clipping plane (Must be positive)
460  *
461  * Replaces the current projection matrix with a perspective matrix
462  * for a given viewing frustum defined by 4 side clip planes that
463  * all cross through the origin and 2 near and far clip planes.
464  *
465  * Since: 1.10
466  * Stability: unstable
467  */
468 COGL_EXPORT void
469 cogl_framebuffer_frustum (CoglFramebuffer *framebuffer,
470                           float left,
471                           float right,
472                           float bottom,
473                           float top,
474                           float z_near,
475                           float z_far);
476 
477 /**
478  * cogl_framebuffer_orthographic:
479  * @framebuffer: A #CoglFramebuffer pointer
480  * @x_1: The x coordinate for the first vertical clipping plane
481  * @y_1: The y coordinate for the first horizontal clipping plane
482  * @x_2: The x coordinate for the second vertical clipping plane
483  * @y_2: The y coordinate for the second horizontal clipping plane
484  * @near: The <emphasis>distance</emphasis> to the near clipping
485  *   plane (will be <emphasis>negative</emphasis> if the plane is
486  *   behind the viewer)
487  * @far: The <emphasis>distance</emphasis> to the far clipping
488  *   plane (will be <emphasis>negative</emphasis> if the plane is
489  *   behind the viewer)
490  *
491  * Replaces the current projection matrix with an orthographic projection
492  * matrix.
493  *
494  * Since: 1.10
495  * Stability: unstable
496  */
497 COGL_EXPORT void
498 cogl_framebuffer_orthographic (CoglFramebuffer *framebuffer,
499                                float x_1,
500                                float y_1,
501                                float x_2,
502                                float y_2,
503                                float near,
504                                float far);
505 
506 /**
507  * cogl_framebuffer_get_projection_matrix:
508  * @framebuffer: A #CoglFramebuffer pointer
509  * @matrix: (out): return location for the projection matrix
510  *
511  * Stores the current projection matrix in @matrix.
512  *
513  * Since: 1.10
514  * Stability: unstable
515  */
516 COGL_EXPORT void
517 cogl_framebuffer_get_projection_matrix (CoglFramebuffer   *framebuffer,
518                                         graphene_matrix_t *matrix);
519 
520 /**
521  * cogl_framebuffer_set_projection_matrix:
522  * @framebuffer: A #CoglFramebuffer pointer
523  * @matrix: the new projection matrix
524  *
525  * Sets @matrix as the new projection matrix.
526  *
527  * Since: 1.10
528  * Stability: unstable
529  */
530 COGL_EXPORT void
531 cogl_framebuffer_set_projection_matrix (CoglFramebuffer         *framebuffer,
532                                         const graphene_matrix_t *matrix);
533 
534 /**
535  * cogl_framebuffer_push_scissor_clip:
536  * @framebuffer: A #CoglFramebuffer pointer
537  * @x: left edge of the clip rectangle in window coordinates
538  * @y: top edge of the clip rectangle in window coordinates
539  * @width: width of the clip rectangle
540  * @height: height of the clip rectangle
541  *
542  * Specifies a rectangular clipping area for all subsequent drawing
543  * operations. Any drawing commands that extend outside the rectangle
544  * will be clipped so that only the portion inside the rectangle will
545  * be displayed. The rectangle dimensions are not transformed by the
546  * current model-view matrix.
547  *
548  * The rectangle is intersected with the current clip region. To undo
549  * the effect of this function, call cogl_framebuffer_pop_clip().
550  *
551  * Since: 1.10
552  * Stability: unstable
553  */
554 COGL_EXPORT void
555 cogl_framebuffer_push_scissor_clip (CoglFramebuffer *framebuffer,
556                                     int x,
557                                     int y,
558                                     int width,
559                                     int height);
560 
561 /**
562  * cogl_framebuffer_push_rectangle_clip:
563  * @framebuffer: A #CoglFramebuffer pointer
564  * @x_1: x coordinate for top left corner of the clip rectangle
565  * @y_1: y coordinate for top left corner of the clip rectangle
566  * @x_2: x coordinate for bottom right corner of the clip rectangle
567  * @y_2: y coordinate for bottom right corner of the clip rectangle
568  *
569  * Specifies a modelview transformed rectangular clipping area for all
570  * subsequent drawing operations. Any drawing commands that extend
571  * outside the rectangle will be clipped so that only the portion
572  * inside the rectangle will be displayed. The rectangle dimensions
573  * are transformed by the current model-view matrix.
574  *
575  * The rectangle is intersected with the current clip region. To undo
576  * the effect of this function, call cogl_framebuffer_pop_clip().
577  *
578  * Since: 1.10
579  * Stability: unstable
580  */
581 COGL_EXPORT void
582 cogl_framebuffer_push_rectangle_clip (CoglFramebuffer *framebuffer,
583                                       float x_1,
584                                       float y_1,
585                                       float x_2,
586                                       float y_2);
587 
588 /**
589  * cogl_framebuffer_push_primitive_clip: (skip)
590  * @framebuffer: A #CoglFramebuffer pointer
591  * @primitive: A #CoglPrimitive describing a flat 2D shape
592  * @bounds_x1: x coordinate for the top-left corner of the primitives
593  *             bounds
594  * @bounds_y1: y coordinate for the top-left corner of the primitives
595  *             bounds
596  * @bounds_x2: x coordinate for the bottom-right corner of the
597  *             primitives bounds.
598  * @bounds_y2: y coordinate for the bottom-right corner of the
599  *             primitives bounds.
600  *
601  * Sets a new clipping area using a 2D shaped described with a
602  * #CoglPrimitive. The shape must not contain self overlapping
603  * geometry and must lie on a single 2D plane. A bounding box of the
604  * 2D shape in local coordinates (the same coordinates used to
605  * describe the shape) must be given. It is acceptable for the bounds
606  * to be larger than the true bounds but behaviour is undefined if the
607  * bounds are smaller than the true bounds.
608  *
609  * The primitive is transformed by the current model-view matrix and
610  * the silhouette is intersected with the previous clipping area.  To
611  * restore the previous clipping area, call
612  * cogl_framebuffer_pop_clip().
613  *
614  * Since: 1.10
615  * Stability: unstable
616  */
617 COGL_EXPORT void
618 cogl_framebuffer_push_primitive_clip (CoglFramebuffer *framebuffer,
619                                       CoglPrimitive *primitive,
620                                       float bounds_x1,
621                                       float bounds_y1,
622                                       float bounds_x2,
623                                       float bounds_y2);
624 
625 COGL_EXPORT void
626 cogl_framebuffer_push_region_clip (CoglFramebuffer *framebuffer,
627                                    cairo_region_t  *region);
628 
629 /**
630  * cogl_framebuffer_pop_clip:
631  * @framebuffer: A #CoglFramebuffer pointer
632  *
633  * Reverts the clipping region to the state before the last call to
634  * cogl_framebuffer_push_scissor_clip(), cogl_framebuffer_push_rectangle_clip()
635  * cogl_framebuffer_push_path_clip(), or cogl_framebuffer_push_primitive_clip().
636  *
637  * Since: 1.10
638  * Stability: unstable
639  */
640 COGL_EXPORT void
641 cogl_framebuffer_pop_clip (CoglFramebuffer *framebuffer);
642 
643 /**
644  * cogl_framebuffer_get_red_bits:
645  * @framebuffer: a pointer to a #CoglFramebuffer
646  *
647  * Retrieves the number of red bits of @framebuffer
648  *
649  * Return value: the number of bits
650  *
651  * Since: 1.8
652  * Stability: unstable
653  */
654 COGL_EXPORT int
655 cogl_framebuffer_get_red_bits (CoglFramebuffer *framebuffer);
656 
657 /**
658  * cogl_framebuffer_get_green_bits:
659  * @framebuffer: a pointer to a #CoglFramebuffer
660  *
661  * Retrieves the number of green bits of @framebuffer
662  *
663  * Return value: the number of bits
664  *
665  * Since: 1.8
666  * Stability: unstable
667  */
668 COGL_EXPORT int
669 cogl_framebuffer_get_green_bits (CoglFramebuffer *framebuffer);
670 
671 /**
672  * cogl_framebuffer_get_blue_bits:
673  * @framebuffer: a pointer to a #CoglFramebuffer
674  *
675  * Retrieves the number of blue bits of @framebuffer
676  *
677  * Return value: the number of bits
678  *
679  * Since: 1.8
680  * Stability: unstable
681  */
682 COGL_EXPORT int
683 cogl_framebuffer_get_blue_bits (CoglFramebuffer *framebuffer);
684 
685 /**
686  * cogl_framebuffer_get_alpha_bits:
687  * @framebuffer: a pointer to a #CoglFramebuffer
688  *
689  * Retrieves the number of alpha bits of @framebuffer
690  *
691  * Return value: the number of bits
692  *
693  * Since: 1.8
694  * Stability: unstable
695  */
696 COGL_EXPORT int
697 cogl_framebuffer_get_alpha_bits (CoglFramebuffer *framebuffer);
698 
699 /**
700  * cogl_framebuffer_get_depth_bits:
701  * @framebuffer: a pointer to a #CoglFramebuffer
702  *
703  * Retrieves the number of depth bits of @framebuffer
704  *
705  * Return value: the number of bits
706  *
707  * Since: 2.0
708  * Stability: unstable
709  */
710 COGL_EXPORT int
711 cogl_framebuffer_get_depth_bits (CoglFramebuffer *framebuffer);
712 
713 /*
714  * cogl_framebuffer_get_is_stereo:
715  * @framebuffer: a pointer to a #CoglFramebuffer
716  *
717  * Retrieves whether @framebuffer has separate left and right
718  * buffers for use with stereo drawing. See
719  * cogl_framebuffer_set_stereo_mode().
720  *
721  * Return value: %TRUE if @framebuffer has separate left and
722  * right buffers.
723  *
724  * Since: 1.20
725  * Stability: unstable
726  */
727 COGL_EXPORT gboolean
728 cogl_framebuffer_get_is_stereo (CoglFramebuffer *framebuffer);
729 
730 /**
731  * cogl_framebuffer_get_dither_enabled:
732  * @framebuffer: a pointer to a #CoglFramebuffer
733  *
734  * Returns whether dithering has been requested for the given @framebuffer.
735  * See cogl_framebuffer_set_dither_enabled() for more details about dithering.
736  *
737  * <note>This may return %TRUE even when the underlying @framebuffer
738  * display pipeline does not support dithering. This value only represents
739  * the user's request for dithering.</note>
740  *
741  * Return value: %TRUE if dithering has been requested or %FALSE if not.
742  * Since: 1.8
743  * Stability: unstable
744  */
745 COGL_EXPORT gboolean
746 cogl_framebuffer_get_dither_enabled (CoglFramebuffer *framebuffer);
747 
748 /**
749  * cogl_framebuffer_set_dither_enabled:
750  * @framebuffer: a pointer to a #CoglFramebuffer
751  * @dither_enabled: %TRUE to enable dithering or %FALSE to disable
752  *
753  * Enables or disabled dithering if supported by the hardware.
754  *
755  * Dithering is a hardware dependent technique to increase the visible
756  * color resolution beyond what the underlying hardware supports by playing
757  * tricks with the colors placed into the framebuffer to give the illusion
758  * of other colors. (For example this can be compared to half-toning used
759  * by some news papers to show varying levels of grey even though their may
760  * only be black and white are available).
761  *
762  * If the current display pipeline for @framebuffer does not support dithering
763  * then this has no affect.
764  *
765  * Dithering is enabled by default.
766  *
767  * Since: 1.8
768  * Stability: unstable
769  */
770 COGL_EXPORT void
771 cogl_framebuffer_set_dither_enabled (CoglFramebuffer *framebuffer,
772                                      gboolean dither_enabled);
773 
774 /**
775  * cogl_framebuffer_get_depth_write_enabled:
776  * @framebuffer: a pointer to a #CoglFramebuffer
777  *
778  * Queries whether depth buffer writing is enabled for @framebuffer. This
779  * can be controlled via cogl_framebuffer_set_depth_write_enabled().
780  *
781  * Return value: %TRUE if depth writing is enabled or %FALSE if not.
782  * Since: 1.18
783  * Stability: unstable
784  */
785 COGL_EXPORT gboolean
786 cogl_framebuffer_get_depth_write_enabled (CoglFramebuffer *framebuffer);
787 
788 /**
789  * cogl_framebuffer_set_depth_write_enabled:
790  * @framebuffer: a pointer to a #CoglFramebuffer
791  * @depth_write_enabled: %TRUE to enable depth writing or %FALSE to disable
792  *
793  * Enables or disables depth buffer writing when rendering to @framebuffer.
794  * If depth writing is enabled for both the framebuffer and the rendering
795  * pipeline, and the framebuffer has an associated depth buffer, depth
796  * information will be written to this buffer during rendering.
797  *
798  * Depth buffer writing is enabled by default.
799  *
800  * Since: 1.18
801  * Stability: unstable
802  */
803 COGL_EXPORT void
804 cogl_framebuffer_set_depth_write_enabled (CoglFramebuffer *framebuffer,
805                                           gboolean depth_write_enabled);
806 
807 /**
808  * cogl_framebuffer_get_stereo_mode:
809  * @framebuffer: a pointer to a #CoglFramebuffer
810  *
811  * Gets the current #CoglStereoMode, which defines which stereo buffers
812  * should be drawn to. See cogl_framebuffer_set_stereo_mode().
813  *
814  * Returns: A #CoglStereoMode
815  * Since: 1.20
816  * Stability: unstable
817  */
818 COGL_EXPORT CoglStereoMode
819 cogl_framebuffer_get_stereo_mode (CoglFramebuffer *framebuffer);
820 
821 /**
822  * cogl_framebuffer_set_stereo_mode:
823  * @framebuffer: a pointer to a #CoglFramebuffer
824  * @stereo_mode: A #CoglStereoMode specifying which stereo buffers
825  *               should be drawn tow.
826  *
827  * Sets which stereo buffers should be drawn to. The default
828  * is %COGL_STEREO_BOTH, which means that both the left and
829  * right buffers will be affected by drawing. For this to have
830  * an effect, the display system must support stereo drawables,
831  * and the framebuffer must have been created with stereo
832  * enabled. (See cogl_onscreen_template_set_stereo_enabled(),
833  * cogl_framebuffer_get_is_stereo().)
834  *
835  * Since: 1.20
836  * Stability: unstable
837  */
838 COGL_EXPORT void
839 cogl_framebuffer_set_stereo_mode (CoglFramebuffer *framebuffer,
840 				  CoglStereoMode stereo_mode);
841 
842 /**
843  * cogl_framebuffer_set_samples_per_pixel:
844  * @framebuffer: A #CoglFramebuffer framebuffer
845  * @samples_per_pixel: The minimum number of samples per pixel
846  *
847  * Requires that when rendering to @framebuffer then @n point samples
848  * should be made per pixel which will all contribute to the final
849  * resolved color for that pixel. The idea is that the hardware aims
850  * to get quality similar to what you would get if you rendered
851  * everything twice as big (for 4 samples per pixel) and then scaled
852  * that image back down with filtering. It can effectively remove the
853  * jagged edges of polygons and should be more efficient than if you
854  * were to manually render at a higher resolution and downscale
855  * because the hardware is often able to take some shortcuts. For
856  * example the GPU may only calculate a single texture sample for all
857  * points of a single pixel, and for tile based architectures all the
858  * extra sample data (such as depth and stencil samples) may be
859  * handled on-chip and so avoid increased demand on system memory
860  * bandwidth.
861  *
862  * By default this value is usually set to 0 and that is referred to
863  * as "single-sample" rendering. A value of 1 or greater is referred
864  * to as "multisample" rendering.
865  *
866  * <note>There are some semantic differences between single-sample
867  * rendering and multisampling with just 1 point sample such as it
868  * being redundant to use the cogl_framebuffer_resolve_samples() and
869  * cogl_framebuffer_resolve_samples_region() apis with single-sample
870  * rendering.</note>
871  *
872  * <note>It's recommended that
873  * cogl_framebuffer_resolve_samples_region() be explicitly used at the
874  * end of rendering to a point sample buffer to minimize the number of
875  * samples that get resolved. By default Cogl will implicitly resolve
876  * all framebuffer samples but if only a small region of a
877  * framebuffer has changed this can lead to redundant work being
878  * done.</note>
879  *
880  * Since: 1.8
881  * Stability: unstable
882  */
883 COGL_EXPORT void
884 cogl_framebuffer_set_samples_per_pixel (CoglFramebuffer *framebuffer,
885                                         int samples_per_pixel);
886 
887 /**
888  * cogl_framebuffer_get_samples_per_pixel:
889  * @framebuffer: A #CoglFramebuffer framebuffer
890  *
891  * Gets the number of points that are sampled per-pixel when
892  * rasterizing geometry. Usually by default this will return 0 which
893  * means that single-sample not multisample rendering has been chosen.
894  * When using a GPU supporting multisample rendering it's possible to
895  * increase the number of samples per pixel using
896  * cogl_framebuffer_set_samples_per_pixel().
897  *
898  * Calling cogl_framebuffer_get_samples_per_pixel() before the
899  * framebuffer has been allocated will simply return the value set
900  * using cogl_framebuffer_set_samples_per_pixel(). After the
901  * framebuffer has been allocated the value will reflect the actual
902  * number of samples that will be made by the GPU.
903  *
904  * Returns: The number of point samples made per pixel when
905  *          rasterizing geometry or 0 if single-sample rendering
906  *          has been chosen.
907  *
908  * Since: 1.10
909  * Stability: unstable
910  */
911 COGL_EXPORT int
912 cogl_framebuffer_get_samples_per_pixel (CoglFramebuffer *framebuffer);
913 
914 
915 /**
916  * cogl_framebuffer_resolve_samples:
917  * @framebuffer: A #CoglFramebuffer framebuffer
918  *
919  * When point sample rendering (also known as multisample rendering)
920  * has been enabled via cogl_framebuffer_set_samples_per_pixel()
921  * then you can optionally call this function (or
922  * cogl_framebuffer_resolve_samples_region()) to explicitly resolve
923  * the point samples into values for the final color buffer.
924  *
925  * Some GPUs will implicitly resolve the point samples during
926  * rendering and so this function is effectively a nop, but with other
927  * architectures it is desirable to defer the resolve step until the
928  * end of the frame.
929  *
930  * Since Cogl will automatically ensure samples are resolved if the
931  * target color buffer is used as a source this API only needs to be
932  * used if explicit control is desired - perhaps because you want to
933  * ensure that the resolve is completed in advance to avoid later
934  * having to wait for the resolve to complete.
935  *
936  * If you are performing incremental updates to a framebuffer you
937  * should consider using cogl_framebuffer_resolve_samples_region()
938  * instead to avoid resolving redundant pixels.
939  *
940  * Since: 1.8
941  * Stability: unstable
942  */
943 COGL_EXPORT void
944 cogl_framebuffer_resolve_samples (CoglFramebuffer *framebuffer);
945 
946 /**
947  * cogl_framebuffer_resolve_samples_region:
948  * @framebuffer: A #CoglFramebuffer framebuffer
949  * @x: top-left x coordinate of region to resolve
950  * @y: top-left y coordinate of region to resolve
951  * @width: width of region to resolve
952  * @height: height of region to resolve
953  *
954  * When point sample rendering (also known as multisample rendering)
955  * has been enabled via cogl_framebuffer_set_samples_per_pixel()
956  * then you can optionally call this function (or
957  * cogl_framebuffer_resolve_samples()) to explicitly resolve the point
958  * samples into values for the final color buffer.
959  *
960  * Some GPUs will implicitly resolve the point samples during
961  * rendering and so this function is effectively a nop, but with other
962  * architectures it is desirable to defer the resolve step until the
963  * end of the frame.
964  *
965  * Use of this API is recommended if incremental, small updates to
966  * a framebuffer are being made because by default Cogl will
967  * implicitly resolve all the point samples of the framebuffer which
968  * can result in redundant work if only a small number of samples have
969  * changed.
970  *
971  * Because some GPUs implicitly resolve point samples this function
972  * only guarantees that at-least the region specified will be resolved
973  * and if you have rendered to a larger region then it's possible that
974  * other samples may be implicitly resolved.
975  *
976  * Since: 1.8
977  * Stability: unstable
978  */
979 COGL_EXPORT void
980 cogl_framebuffer_resolve_samples_region (CoglFramebuffer *framebuffer,
981                                          int x,
982                                          int y,
983                                          int width,
984                                          int height);
985 
986 /**
987  * cogl_framebuffer_get_context:
988  * @framebuffer: A #CoglFramebuffer
989  *
990  * Can be used to query the #CoglContext a given @framebuffer was
991  * instantiated within. This is the #CoglContext that was passed to
992  * cogl_onscreen_new() for example.
993  *
994  * Return value: (transfer none): The #CoglContext that the given
995  *               @framebuffer was instantiated within.
996  * Since: 1.8
997  * Stability: unstable
998  */
999 COGL_EXPORT CoglContext *
1000 cogl_framebuffer_get_context (CoglFramebuffer *framebuffer);
1001 
1002 /**
1003  * cogl_framebuffer_clear:
1004  * @framebuffer: A #CoglFramebuffer
1005  * @buffers: A mask of #CoglBufferBit<!-- -->'s identifying which auxiliary
1006  *   buffers to clear
1007  * @color: The color to clear the color buffer too if specified in
1008  *         @buffers.
1009  *
1010  * Clears all the auxiliary buffers identified in the @buffers mask, and if
1011  * that includes the color buffer then the specified @color is used.
1012  *
1013  * Since: 1.8
1014  * Stability: unstable
1015  */
1016 COGL_EXPORT void
1017 cogl_framebuffer_clear (CoglFramebuffer *framebuffer,
1018                         unsigned long buffers,
1019                         const CoglColor *color);
1020 
1021 /**
1022  * cogl_framebuffer_clear4f:
1023  * @framebuffer: A #CoglFramebuffer
1024  * @buffers: A mask of #CoglBufferBit<!-- -->'s identifying which auxiliary
1025  *   buffers to clear
1026  * @red: The red component of color to clear the color buffer too if
1027  *       specified in @buffers.
1028  * @green: The green component of color to clear the color buffer too if
1029  *         specified in @buffers.
1030  * @blue: The blue component of color to clear the color buffer too if
1031  *        specified in @buffers.
1032  * @alpha: The alpha component of color to clear the color buffer too if
1033  *         specified in @buffers.
1034  *
1035  * Clears all the auxiliary buffers identified in the @buffers mask, and if
1036  * that includes the color buffer then the specified @color is used.
1037  *
1038  * Since: 1.8
1039  * Stability: unstable
1040  */
1041 COGL_EXPORT void
1042 cogl_framebuffer_clear4f (CoglFramebuffer *framebuffer,
1043                           unsigned long buffers,
1044                           float red,
1045                           float green,
1046                           float blue,
1047                           float alpha);
1048 
1049 /**
1050  * cogl_framebuffer_draw_primitive: (skip)
1051  * @framebuffer: A destination #CoglFramebuffer
1052  * @pipeline: A #CoglPipeline state object
1053  * @primitive: A #CoglPrimitive geometry object
1054  *
1055  * Draws the given @primitive geometry to the specified destination
1056  * @framebuffer using the graphics processing state described by @pipeline.
1057  *
1058  * This drawing api doesn't support high-level meta texture types such
1059  * as #CoglTexture2DSliced so it is the user's responsibility to
1060  * ensure that only low-level textures that can be directly sampled by
1061  * a GPU such as #CoglTexture2D are associated with layers of the given
1062  * @pipeline.
1063  *
1064  * <note>This api doesn't support any of the legacy global state options such
1065  * as cogl_set_depth_test_enabled() or
1066  * cogl_set_backface_culling_enabled().</note>
1067  *
1068  * Stability: unstable
1069  * Since: 1.10
1070  * Deprecated: 1.16: Use #CoglPrimitive<!-- -->s and
1071  *                   cogl_primitive_draw() instead
1072  */
1073 COGL_DEPRECATED_FOR (cogl_primitive_draw)
1074 COGL_EXPORT void
1075 cogl_framebuffer_draw_primitive (CoglFramebuffer *framebuffer,
1076                                  CoglPipeline *pipeline,
1077                                  CoglPrimitive *primitive);
1078 
1079 /**
1080  * cogl_framebuffer_draw_rectangle:
1081  * @framebuffer: A destination #CoglFramebuffer
1082  * @pipeline: A #CoglPipeline state object
1083  * @x_1: X coordinate of the top-left corner
1084  * @y_1: Y coordinate of the top-left corner
1085  * @x_2: X coordinate of the bottom-right corner
1086  * @y_2: Y coordinate of the bottom-right corner
1087  *
1088  * Draws a rectangle to @framebuffer with the given @pipeline state
1089  * and with the top left corner positioned at (@x_1, @y_1) and the
1090  * bottom right corner positioned at (@x_2, @y_2).
1091  *
1092  * <note>The position is the position before the rectangle has been
1093  * transformed by the model-view matrix and the projection
1094  * matrix.</note>
1095  *
1096  * <note>If you want to describe a rectangle with a texture mapped on
1097  * it then you can use
1098  * cogl_framebuffer_draw_textured_rectangle().</note>
1099  *
1100  * Since: 1.10
1101  * Stability: unstable
1102  */
1103 COGL_EXPORT void
1104 cogl_framebuffer_draw_rectangle (CoglFramebuffer *framebuffer,
1105                                  CoglPipeline *pipeline,
1106                                  float x_1,
1107                                  float y_1,
1108                                  float x_2,
1109                                  float y_2);
1110 
1111 /**
1112  * cogl_framebuffer_draw_textured_rectangle:
1113  * @framebuffer: A destination #CoglFramebuffer
1114  * @pipeline: A #CoglPipeline state object
1115  * @x_1: x coordinate upper left on screen.
1116  * @y_1: y coordinate upper left on screen.
1117  * @x_2: x coordinate lower right on screen.
1118  * @y_2: y coordinate lower right on screen.
1119  * @s_1: S texture coordinate of the top-left coorner
1120  * @t_1: T texture coordinate of the top-left coorner
1121  * @s_2: S texture coordinate of the bottom-right coorner
1122  * @t_2: T texture coordinate of the bottom-right coorner
1123  *
1124  * Draws a textured rectangle to @framebuffer using the given
1125  * @pipeline state with the top left corner positioned at (@x_1, @y_1)
1126  * and the bottom right corner positioned at (@x_2, @y_2). The top
1127  * left corner will have texture coordinates of (@s_1, @t_1) and the
1128  * bottom right corner will have texture coordinates of (@s_2, @t_2).
1129  *
1130  * <note>The position is the position before the rectangle has been
1131  * transformed by the model-view matrix and the projection
1132  * matrix.</note>
1133  *
1134  * This is a high level drawing api that can handle any kind of
1135  * #CoglMetaTexture texture such as #CoglTexture2DSliced textures
1136  * which may internally be comprised of multiple low-level textures.
1137  * This is unlike low-level drawing apis such as cogl_primitive_draw()
1138  * which only support low level texture types that are directly
1139  * supported by GPUs such as #CoglTexture2D.
1140  *
1141  * <note>The given texture coordinates will only be used for the first
1142  * texture layer of the pipeline and if your pipeline has more than
1143  * one layer then all other layers will have default texture
1144  * coordinates of @s_1=0.0 @t_1=0.0 @s_2=1.0 @t_2=1.0 </note>
1145  *
1146  * The given texture coordinates should always be normalized such that
1147  * (0, 0) corresponds to the top left and (1, 1) corresponds to the
1148  * bottom right. To map an entire texture across the rectangle pass
1149  * in @s_1=0, @t_1=0, @s_2=1, @t_2=1.
1150  *
1151  * Since: 1.10
1152  * Stability: unstable
1153  */
1154 COGL_EXPORT void
1155 cogl_framebuffer_draw_textured_rectangle (CoglFramebuffer *framebuffer,
1156                                           CoglPipeline *pipeline,
1157                                           float x_1,
1158                                           float y_1,
1159                                           float x_2,
1160                                           float y_2,
1161                                           float s_1,
1162                                           float t_1,
1163                                           float s_2,
1164                                           float t_2);
1165 
1166 /**
1167  * cogl_framebuffer_draw_multitextured_rectangle:
1168  * @framebuffer: A destination #CoglFramebuffer
1169  * @pipeline: A #CoglPipeline state object
1170  * @x_1: x coordinate upper left on screen.
1171  * @y_1: y coordinate upper left on screen.
1172  * @x_2: x coordinate lower right on screen.
1173  * @y_2: y coordinate lower right on screen.
1174  * @tex_coords: (in) (array) (transfer none): An array containing groups of
1175  *   4 float values: [s_1, t_1, s_2, t_2] that are interpreted as two texture
1176  *   coordinates; one for the top left texel, and one for the bottom right
1177  *   texel. Each value should be between 0.0 and 1.0, where the coordinate
1178  *   (0.0, 0.0) represents the top left of the texture, and (1.0, 1.0) the
1179  *   bottom right.
1180  * @tex_coords_len: The length of the @tex_coords array. (For one layer
1181  *   and one group of texture coordinates, this would be 4)
1182  *
1183  * Draws a textured rectangle to @framebuffer with the given @pipeline
1184  * state with the top left corner positioned at (@x_1, @y_1) and the
1185  * bottom right corner positioned at (@x_2, @y_2). As a pipeline may
1186  * contain multiple texture layers this interface lets you supply
1187  * texture coordinates for each layer of the pipeline.
1188  *
1189  * <note>The position is the position before the rectangle has been
1190  * transformed by the model-view matrix and the projection
1191  * matrix.</note>
1192  *
1193  * This is a high level drawing api that can handle any kind of
1194  * #CoglMetaTexture texture for the first layer such as
1195  * #CoglTexture2DSliced textures which may internally be comprised of
1196  * multiple low-level textures.  This is unlike low-level drawing apis
1197  * such as cogl_primitive_draw() which only support low level texture
1198  * types that are directly supported by GPUs such as #CoglTexture2D.
1199  *
1200  * <note>This api can not currently handle multiple high-level meta
1201  * texture layers. The first layer may be a high level meta texture
1202  * such as #CoglTexture2DSliced but all other layers much be low
1203  * level textures such as #CoglTexture2D.
1204  *
1205  * The top left texture coordinate for layer 0 of any pipeline will be
1206  * (tex_coords[0], tex_coords[1]) and the bottom right coordinate will
1207  * be (tex_coords[2], tex_coords[3]). The coordinates for layer 1
1208  * would be (tex_coords[4], tex_coords[5]) (tex_coords[6],
1209  * tex_coords[7]) and so on...
1210  *
1211  * The given texture coordinates should always be normalized such that
1212  * (0, 0) corresponds to the top left and (1, 1) corresponds to the
1213  * bottom right. To map an entire texture across the rectangle pass
1214  * in tex_coords[0]=0, tex_coords[1]=0, tex_coords[2]=1,
1215  * tex_coords[3]=1.
1216  *
1217  * The first pair of coordinates are for the first layer (with the
1218  * smallest layer index) and if you supply less texture coordinates
1219  * than there are layers in the current source material then default
1220  * texture coordinates (0.0, 0.0, 1.0, 1.0) are generated.
1221  *
1222  * Since: 1.10
1223  * Stability: unstable
1224  */
1225 COGL_EXPORT void
1226 cogl_framebuffer_draw_multitextured_rectangle (CoglFramebuffer *framebuffer,
1227                                                CoglPipeline *pipeline,
1228                                                float x_1,
1229                                                float y_1,
1230                                                float x_2,
1231                                                float y_2,
1232                                                const float *tex_coords,
1233                                                int tex_coords_len);
1234 
1235 /**
1236  * cogl_framebuffer_draw_rectangles:
1237  * @framebuffer: A destination #CoglFramebuffer
1238  * @pipeline: A #CoglPipeline state object
1239  * @coordinates: (in) (array) (transfer none): an array of coordinates
1240  *   containing groups of 4 float values: [x_1, y_1, x_2, y_2] that are
1241  *   interpreted as two position coordinates; one for the top left of
1242  *   the rectangle (x1, y1), and one for the bottom right of the
1243  *   rectangle (x2, y2).
1244  * @n_rectangles: number of rectangles defined in @coordinates.
1245  *
1246  * Draws a series of rectangles to @framebuffer with the given
1247  * @pipeline state in the same way that
1248  * cogl_framebuffer_draw_rectangle() does.
1249  *
1250  * The top left corner of the first rectangle is positioned at
1251  * (coordinates[0], coordinates[1]) and the bottom right corner is
1252  * positioned at (coordinates[2], coordinates[3]). The positions for
1253  * the second rectangle are (coordinates[4], coordinates[5]) and
1254  * (coordinates[6], coordinates[7]) and so on...
1255  *
1256  * <note>The position is the position before the rectangle has been
1257  * transformed by the model-view matrix and the projection
1258  * matrix.</note>
1259  *
1260  * As a general rule for better performance its recommended to use
1261  * this this API instead of calling
1262  * cogl_framebuffer_draw_textured_rectangle() separately for multiple
1263  * rectangles if all of the rectangles will be drawn together with the
1264  * same @pipeline state.
1265  *
1266  * Since: 1.10
1267  * Stability: unstable
1268  */
1269 COGL_EXPORT void
1270 cogl_framebuffer_draw_rectangles (CoglFramebuffer *framebuffer,
1271                                   CoglPipeline *pipeline,
1272                                   const float *coordinates,
1273                                   unsigned int n_rectangles);
1274 
1275 /**
1276  * cogl_framebuffer_draw_textured_rectangles:
1277  * @framebuffer: A destination #CoglFramebuffer
1278  * @pipeline: A #CoglPipeline state object
1279  * @coordinates: (in) (array) (transfer none): an array containing
1280  *   groups of 8 float values: [x_1, y_1, x_2, y_2, s_1, t_1, s_2, t_2]
1281  *   that have the same meaning as the arguments for
1282  *   cogl_framebuffer_draw_textured_rectangle().
1283  * @n_rectangles: number of rectangles to @coordinates to draw
1284  *
1285  * Draws a series of rectangles to @framebuffer with the given
1286  * @pipeline state in the same way that
1287  * cogl_framebuffer_draw_textured_rectangle() does.
1288  *
1289  * <note>The position is the position before the rectangle has been
1290  * transformed by the model-view matrix and the projection
1291  * matrix.</note>
1292  *
1293  * This is a high level drawing api that can handle any kind of
1294  * #CoglMetaTexture texture such as #CoglTexture2DSliced textures
1295  * which may internally be comprised of multiple low-level textures.
1296  * This is unlike low-level drawing apis such as cogl_primitive_draw()
1297  * which only support low level texture types that are directly
1298  * supported by GPUs such as #CoglTexture2D.
1299  *
1300  * The top left corner of the first rectangle is positioned at
1301  * (coordinates[0], coordinates[1]) and the bottom right corner is
1302  * positioned at (coordinates[2], coordinates[3]). The top left
1303  * texture coordinate is (coordinates[4], coordinates[5]) and the
1304  * bottom right texture coordinate is (coordinates[6],
1305  * coordinates[7]). The coordinates for subsequent rectangles
1306  * are defined similarly by the subsequent coordinates.
1307  *
1308  * As a general rule for better performance its recommended to use
1309  * this this API instead of calling
1310  * cogl_framebuffer_draw_textured_rectangle() separately for multiple
1311  * rectangles if all of the rectangles will be drawn together with the
1312  * same @pipeline state.
1313  *
1314  * The given texture coordinates should always be normalized such that
1315  * (0, 0) corresponds to the top left and (1, 1) corresponds to the
1316  * bottom right. To map an entire texture across the rectangle pass
1317  * in tex_coords[0]=0, tex_coords[1]=0, tex_coords[2]=1,
1318  * tex_coords[3]=1.
1319  *
1320  * Since: 1.10
1321  * Stability: unstable
1322  */
1323 COGL_EXPORT void
1324 cogl_framebuffer_draw_textured_rectangles (CoglFramebuffer *framebuffer,
1325                                            CoglPipeline *pipeline,
1326                                            const float *coordinates,
1327                                            unsigned int n_rectangles);
1328 
1329 /* XXX: Should we take an n_buffers + buffer id array instead of using
1330  * the CoglBufferBits type which doesn't seem future proof? */
1331 /**
1332  * cogl_framebuffer_discard_buffers:
1333  * @framebuffer: A #CoglFramebuffer
1334  * @buffers: A #CoglBufferBit mask of which ancillary buffers you want
1335  *           to discard.
1336  *
1337  * Declares that the specified @buffers no longer need to be referenced
1338  * by any further rendering commands. This can be an important
1339  * optimization to avoid subsequent frames of rendering depending on
1340  * the results of a previous frame.
1341  *
1342  * For example; some tile-based rendering GPUs are able to avoid allocating and
1343  * accessing system memory for the depth and stencil buffer so long as these
1344  * buffers are not required as input for subsequent frames and that can save a
1345  * significant amount of memory bandwidth used to save and restore their
1346  * contents to system memory between frames.
1347  *
1348  * It is currently considered an error to try and explicitly discard the color
1349  * buffer by passing %COGL_BUFFER_BIT_COLOR. This is because the color buffer is
1350  * already implicitly discard when you finish rendering to a #CoglOnscreen
1351  * framebuffer, and it's not meaningful to try and discard the color buffer of
1352  * a #CoglOffscreen framebuffer since they are single-buffered.
1353  *
1354  *
1355  * Since: 1.8
1356  * Stability: unstable
1357  */
1358 COGL_EXPORT void
1359 cogl_framebuffer_discard_buffers (CoglFramebuffer *framebuffer,
1360                                   unsigned long buffers);
1361 
1362 /**
1363  * cogl_framebuffer_finish:
1364  * @framebuffer: A #CoglFramebuffer pointer
1365  *
1366  * This blocks the CPU until all pending rendering associated with the
1367  * specified framebuffer has completed. It's very rare that developers should
1368  * ever need this level of synchronization with the GPU and should never be
1369  * used unless you clearly understand why you need to explicitly force
1370  * synchronization.
1371  *
1372  * One example might be for benchmarking purposes to be sure timing
1373  * measurements reflect the time that the GPU is busy for not just the time it
1374  * takes to queue rendering commands.
1375  *
1376  * Stability: unstable
1377  * Since: 1.10
1378  */
1379 COGL_EXPORT void
1380 cogl_framebuffer_finish (CoglFramebuffer *framebuffer);
1381 
1382 /**
1383  * cogl_framebuffer_read_pixels_into_bitmap:
1384  * @framebuffer: A #CoglFramebuffer
1385  * @x: The x position to read from
1386  * @y: The y position to read from
1387  * @source: Identifies which auxiliary buffer you want to read
1388  *          (only COGL_READ_PIXELS_COLOR_BUFFER supported currently)
1389  * @bitmap: The bitmap to store the results in.
1390  *
1391  * This reads a rectangle of pixels from the given framebuffer where
1392  * position (0, 0) is the top left. The pixel at (x, y) is the first
1393  * read, and a rectangle of pixels with the same size as the bitmap is
1394  * read right and downwards from that point.
1395  *
1396  * Currently Cogl assumes that the framebuffer is in a premultiplied
1397  * format so if the format of @bitmap is non-premultiplied it will
1398  * convert it. To read the pixel values without any conversion you
1399  * should either specify a format that doesn't use an alpha channel or
1400  * use one of the formats ending in PRE.
1401  *
1402  * Return value: %TRUE if the read succeeded or %FALSE otherwise. The
1403  *  function is only likely to fail if the bitmap points to a pixel
1404  *  buffer and it could not be mapped.
1405  * Since: 1.10
1406  * Stability: unstable
1407  */
1408 COGL_EXPORT gboolean
1409 cogl_framebuffer_read_pixels_into_bitmap (CoglFramebuffer *framebuffer,
1410                                           int x,
1411                                           int y,
1412                                           CoglReadPixelsFlags source,
1413                                           CoglBitmap *bitmap);
1414 
1415 /**
1416  * cogl_framebuffer_read_pixels:
1417  * @framebuffer: A #CoglFramebuffer
1418  * @x: The x position to read from
1419  * @y: The y position to read from
1420  * @width: The width of the region of rectangles to read
1421  * @height: The height of the region of rectangles to read
1422  * @format: The pixel format to store the data in
1423  * @pixels: The address of the buffer to store the data in
1424  *
1425  * This is a convenience wrapper around
1426  * cogl_framebuffer_read_pixels_into_bitmap() which allocates a
1427  * temporary #CoglBitmap to read pixel data directly into the given
1428  * buffer. The rowstride of the buffer is assumed to be the width of
1429  * the region times the bytes per pixel of the format. The source for
1430  * the data is always taken from the color buffer. If you want to use
1431  * any other rowstride or source, please use the
1432  * cogl_framebuffer_read_pixels_into_bitmap() function directly.
1433  *
1434  * The implementation of the function looks like this:
1435  *
1436  * |[
1437  * bitmap = cogl_bitmap_new_for_data (context,
1438  *                                    width, height,
1439  *                                    format,
1440  *                                    /<!-- -->* rowstride *<!-- -->/
1441  *                                    bpp * width,
1442  *                                    pixels);
1443  * cogl_framebuffer_read_pixels_into_bitmap (framebuffer,
1444  *                                           x, y,
1445  *                                           COGL_READ_PIXELS_COLOR_BUFFER,
1446  *                                           bitmap);
1447  * cogl_object_unref (bitmap);
1448  * ]|
1449  *
1450  * Return value: %TRUE if the read succeeded or %FALSE otherwise.
1451  * Since: 1.10
1452  * Stability: unstable
1453  */
1454 COGL_EXPORT gboolean
1455 cogl_framebuffer_read_pixels (CoglFramebuffer *framebuffer,
1456                               int x,
1457                               int y,
1458                               int width,
1459                               int height,
1460                               CoglPixelFormat format,
1461                               uint8_t *pixels);
1462 
1463 COGL_EXPORT uint32_t
1464 cogl_framebuffer_error_quark (void);
1465 
1466 /**
1467  * COGL_FRAMEBUFFER_ERROR:
1468  *
1469  * An error domain for reporting #CoglFramebuffer exceptions
1470  */
1471 #define COGL_FRAMEBUFFER_ERROR (cogl_framebuffer_error_quark ())
1472 
1473 typedef enum /*< prefix=COGL_FRAMEBUFFER_ERROR >*/
1474 {
1475   COGL_FRAMEBUFFER_ERROR_ALLOCATE
1476 } CoglFramebufferError;
1477 
1478 /**
1479  * cogl_is_framebuffer:
1480  * @object: A #CoglObject pointer
1481  *
1482  * Gets whether the given object references a #CoglFramebuffer.
1483  *
1484  * Return value: %TRUE if the object references a #CoglFramebuffer
1485  *   and %FALSE otherwise.
1486  * Since: 1.10
1487  * Stability: unstable
1488  */
1489 COGL_EXPORT gboolean
1490 cogl_is_framebuffer (void *object);
1491 
1492 /**
1493  * cogl_blit_framebuffer:
1494  * @framebuffer: The source #CoglFramebuffer
1495  * @dst: The destination #CoglFramebuffer
1496  * @src_x: Source x position
1497  * @src_y: Source y position
1498  * @dst_x: Destination x position
1499  * @dst_y: Destination y position
1500  * @width: Width of region to copy
1501  * @height: Height of region to copy
1502  * @error: optional error object
1503  *
1504  * @return FALSE for an immediately detected error, TRUE otherwise.
1505  *
1506  * This blits a region of the color buffer of the source buffer
1507  * to the destination buffer. This function should only be
1508  * called if the COGL_FEATURE_ID_BLIT_FRAMEBUFFER feature is
1509  * advertised.
1510  *
1511  * The source and destination rectangles are defined in offscreen
1512  * framebuffer orientation. When copying between an offscreen and
1513  * onscreen framebuffers, the image is y-flipped accordingly.
1514  *
1515  * The two buffers must have the same value types (e.g. floating-point,
1516  * unsigned int, signed int, or fixed-point), but color formats do not
1517  * need to match. This limitation comes from OpenGL ES 3.0 definition
1518  * of glBlitFramebuffer.
1519  *
1520  * Note that this function differs a lot from the glBlitFramebuffer
1521  * function provided by the GL_EXT_framebuffer_blit extension. Notably
1522  * it doesn't support having different sizes for the source and
1523  * destination rectangle. This doesn't seem
1524  * like a particularly useful feature. If the application wanted to
1525  * scale the results it may make more sense to draw a primitive
1526  * instead.
1527  *
1528  * The GL function is documented to be affected by the scissor. This
1529  * function therefore ensure that an empty clip stack is flushed
1530  * before performing the blit which means the scissor is effectively
1531  * ignored.
1532  *
1533  * The function also doesn't support specifying the buffers to copy
1534  * and instead only the color buffer is copied. When copying the depth
1535  * or stencil buffers the extension on GLES2.0 only supports copying
1536  * the full buffer which would be awkward to document with this
1537  * API. If we wanted to support that feature it may be better to have
1538  * a separate function to copy the entire buffer for a given mask.
1539  *
1540  * The @c error argument is optional, it can be NULL. If it is not NULL
1541  * and this function returns FALSE, an error object with a code from
1542  * COGL_SYSTEM_ERROR will be created.
1543  */
1544 COGL_EXPORT gboolean
1545 cogl_blit_framebuffer (CoglFramebuffer *framebuffer,
1546                        CoglFramebuffer *dst,
1547                        int src_x,
1548                        int src_y,
1549                        int dst_x,
1550                        int dst_y,
1551                        int width,
1552                        int height,
1553                        GError **error);
1554 
1555 /**
1556  * cogl_framebuffer_flush:
1557  * @framebuffer: A #CoglFramebuffer pointer
1558  *
1559  * Flushes @framebuffer to ensure the current batch of commands is
1560  * submitted to the GPU.
1561  *
1562  * Unlike cogl_framebuffer_finish(), this does not block the CPU.
1563  */
1564 COGL_EXPORT void
1565 cogl_framebuffer_flush (CoglFramebuffer *framebuffer);
1566 
1567 /**
1568  * cogl_framebuffer_create_timestamp_query: (skip)
1569  *
1570  * Creates a query for the GPU timestamp that will complete upon completion of
1571  * all previously submitted GL commands related to this framebuffer. E.g. when
1572  * the rendering is finished on this framebuffer.
1573  *
1574  * This function should only be called if the COGL_FEATURE_ID_TIMESTAMP_QUERY
1575  * feature is advertised.
1576  */
1577 COGL_EXPORT CoglTimestampQuery *
1578 cogl_framebuffer_create_timestamp_query (CoglFramebuffer *framebuffer);
1579 
1580 G_END_DECLS
1581 
1582 #endif /* __COGL_FRAMEBUFFER_H */
1583