1 //
2 // Copyright (c) 2013 Mikko Mononen memon@inside.org
3 //
4 // This software is provided 'as-is', without any express or implied
5 // warranty.  In no event will the authors be held liable for any damages
6 // arising from the use of this software.
7 // Permission is granted to anyone to use this software for any purpose,
8 // including commercial applications, and to alter it and redistribute it
9 // freely, subject to the following restrictions:
10 // 1. The origin of this software must not be misrepresented; you must not
11 //    claim that you wrote the original software. If you use this software
12 //    in a product, an acknowledgment in the product documentation would be
13 //    appreciated but is not required.
14 // 2. Altered source versions must be plainly marked as such, and must not be
15 //    misrepresented as being the original software.
16 // 3. This notice may not be removed or altered from any source distribution.
17 //
18 
19 #ifndef NANOVG_H
20 #define NANOVG_H
21 
22 #ifdef __cplusplus
23 extern "C" {
24 #endif
25 
26 #define NVG_PI 3.14159265358979323846264338327f
27 
28 #ifdef _MSC_VER
29 #pragma warning(push)
30 #pragma warning(disable: 4201)  // nonstandard extension used : nameless struct/union
31 #endif
32 
33 typedef struct NVGcontext NVGcontext;
34 
35 struct NVGcolor {
36 	union {
37 		float rgba[4];
38 		struct {
39 			float r,g,b,a;
40 		};
41 	};
42 };
43 typedef struct NVGcolor NVGcolor;
44 
45 struct NVGpaint {
46 	float xform[6];
47 	float extent[2];
48 	float radius;
49 	float feather;
50 	NVGcolor innerColor;
51 	NVGcolor outerColor;
52 	int image;
53 };
54 typedef struct NVGpaint NVGpaint;
55 
56 enum NVGwinding {
57 	NVG_CCW = 1,			// Winding for solid shapes
58 	NVG_CW = 2,				// Winding for holes
59 };
60 
61 enum NVGsolidity {
62 	NVG_SOLID = 1,			// CCW
63 	NVG_HOLE = 2,			// CW
64 };
65 
66 enum NVGlineCap {
67 	NVG_BUTT,
68 	NVG_ROUND,
69 	NVG_SQUARE,
70 	NVG_BEVEL,
71 	NVG_MITER,
72 };
73 
74 enum NVGalign {
75 	// Horizontal align
76 	NVG_ALIGN_LEFT 		= 1<<0,	// Default, align text horizontally to left.
77 	NVG_ALIGN_CENTER 	= 1<<1,	// Align text horizontally to center.
78 	NVG_ALIGN_RIGHT 	= 1<<2,	// Align text horizontally to right.
79 	// Vertical align
80 	NVG_ALIGN_TOP 		= 1<<3,	// Align text vertically to top.
81 	NVG_ALIGN_MIDDLE	= 1<<4,	// Align text vertically to middle.
82 	NVG_ALIGN_BOTTOM	= 1<<5,	// Align text vertically to bottom.
83 	NVG_ALIGN_BASELINE	= 1<<6, // Default, align text vertically to baseline.
84 };
85 
86 struct NVGglyphPosition {
87 	const char* str;	// Position of the glyph in the input string.
88 	float x;			// The x-coordinate of the logical glyph position.
89 	float minx, maxx;	// The bounds of the glyph shape.
90 };
91 typedef struct NVGglyphPosition NVGglyphPosition;
92 
93 struct NVGtextRow {
94 	const char* start;	// Pointer to the input text where the row starts.
95 	const char* end;	// Pointer to the input text where the row ends (one past the last character).
96 	const char* next;	// Pointer to the beginning of the next row.
97 	float width;		// Logical width of the row.
98 	float minx, maxx;	// Actual bounds of the row. Logical with and bounds can differ because of kerning and some parts over extending.
99 };
100 typedef struct NVGtextRow NVGtextRow;
101 
102 enum NVGimageFlags {
103 	NVG_IMAGE_GENERATE_MIPMAPS		= 1<<0,		// Generate mipmaps during creation of the image.
104 	NVG_IMAGE_REPEATX			= 1<<1,		// Repeat image in X direction.
105 	NVG_IMAGE_REPEATY			= 1<<2,		// Repeat image in Y direction.
106 	NVG_IMAGE_FLIPY				= 1<<3,		// Flips (inverses) image in Y direction when rendered.
107 	NVG_IMAGE_PREMULTIPLIED			= 1<<4,		// Image data has premultiplied alpha.
108 };
109 
110 // Begin drawing a new frame
111 // Calls to nanovg drawing API should be wrapped in nvgBeginFrame() & nvgEndFrame()
112 // nvgBeginFrame() defines the size of the window to render to in relation currently
113 // set viewport (i.e. glViewport on GL backends). Device pixel ration allows to
114 // control the rendering on Hi-DPI devices.
115 // For example, GLFW returns two dimension for an opened window: window size and
116 // frame buffer size. In that case you would set windowWidth/Height to the window size
117 // devicePixelRatio to: frameBufferWidth / windowWidth.
118 void nvgBeginFrame(NVGcontext* ctx, int windowWidth, int windowHeight, float devicePixelRatio);
119 
120 // Cancels drawing the current frame.
121 void nvgCancelFrame(NVGcontext* ctx);
122 
123 // Ends drawing flushing remaining render state.
124 void nvgEndFrame(NVGcontext* ctx);
125 
126 //
127 // Color utils
128 //
129 // Colors in NanoVG are stored as unsigned ints in ABGR format.
130 
131 // Returns a color value from red, green, blue values. Alpha will be set to 255 (1.0f).
132 NVGcolor nvgRGB(unsigned char r, unsigned char g, unsigned char b);
133 
134 // Returns a color value from red, green, blue values. Alpha will be set to 1.0f.
135 NVGcolor nvgRGBf(float r, float g, float b);
136 
137 
138 // Returns a color value from red, green, blue and alpha values.
139 NVGcolor nvgRGBA(unsigned char r, unsigned char g, unsigned char b, unsigned char a);
140 
141 // Returns a color value from red, green, blue and alpha values.
142 NVGcolor nvgRGBAf(float r, float g, float b, float a);
143 
144 
145 // Linearly interpolates from color c0 to c1, and returns resulting color value.
146 NVGcolor nvgLerpRGBA(NVGcolor c0, NVGcolor c1, float u);
147 
148 // Sets transparency of a color value.
149 NVGcolor nvgTransRGBA(NVGcolor c0, unsigned char a);
150 
151 // Sets transparency of a color value.
152 NVGcolor nvgTransRGBAf(NVGcolor c0, float a);
153 
154 // Returns color value specified by hue, saturation and lightness.
155 // HSL values are all in range [0..1], alpha will be set to 255.
156 NVGcolor nvgHSL(float h, float s, float l);
157 
158 // Returns color value specified by hue, saturation and lightness and alpha.
159 // HSL values are all in range [0..1], alpha in range [0..255]
160 NVGcolor nvgHSLA(float h, float s, float l, unsigned char a);
161 
162 //
163 // State Handling
164 //
165 // NanoVG contains state which represents how paths will be rendered.
166 // The state contains transform, fill and stroke styles, text and font styles,
167 // and scissor clipping.
168 
169 // Pushes and saves the current render state into a state stack.
170 // A matching nvgRestore() must be used to restore the state.
171 void nvgSave(NVGcontext* ctx);
172 
173 // Pops and restores current render state.
174 void nvgRestore(NVGcontext* ctx);
175 
176 // Resets current render state to default values. Does not affect the render state stack.
177 void nvgReset(NVGcontext* ctx);
178 
179 //
180 // Render styles
181 //
182 // Fill and stroke render style can be either a solid color or a paint which is a gradient or a pattern.
183 // Solid color is simply defined as a color value, different kinds of paints can be created
184 // using nvgLinearGradient(), nvgBoxGradient(), nvgRadialGradient() and nvgImagePattern().
185 //
186 // Current render style can be saved and restored using nvgSave() and nvgRestore().
187 
188 // Sets current stroke style to a solid color.
189 void nvgStrokeColor(NVGcontext* ctx, NVGcolor color);
190 
191 // Sets current stroke style to a paint, which can be a one of the gradients or a pattern.
192 void nvgStrokePaint(NVGcontext* ctx, NVGpaint paint);
193 
194 // Sets current fill style to a solid color.
195 void nvgFillColor(NVGcontext* ctx, NVGcolor color);
196 
197 // Sets current fill style to a paint, which can be a one of the gradients or a pattern.
198 void nvgFillPaint(NVGcontext* ctx, NVGpaint paint);
199 
200 // Sets the miter limit of the stroke style.
201 // Miter limit controls when a sharp corner is beveled.
202 void nvgMiterLimit(NVGcontext* ctx, float limit);
203 
204 // Sets the stroke width of the stroke style.
205 void nvgStrokeWidth(NVGcontext* ctx, float size);
206 
207 // Sets how the end of the line (cap) is drawn,
208 // Can be one of: NVG_BUTT (default), NVG_ROUND, NVG_SQUARE.
209 void nvgLineCap(NVGcontext* ctx, int cap);
210 
211 // Sets how sharp path corners are drawn.
212 // Can be one of NVG_MITER (default), NVG_ROUND, NVG_BEVEL.
213 void nvgLineJoin(NVGcontext* ctx, int join);
214 
215 // Sets the transparency applied to all rendered shapes.
216 // Already transparent paths will get proportionally more transparent as well.
217 void nvgGlobalAlpha(NVGcontext* ctx, float alpha);
218 
219 //
220 // Transforms
221 //
222 // The paths, gradients, patterns and scissor region are transformed by an transformation
223 // matrix at the time when they are passed to the API.
224 // The current transformation matrix is a affine matrix:
225 //   [sx kx tx]
226 //   [ky sy ty]
227 //   [ 0  0  1]
228 // Where: sx,sy define scaling, kx,ky skewing, and tx,ty translation.
229 // The last row is assumed to be 0,0,1 and is not stored.
230 //
231 // Apart from nvgResetTransform(), each transformation function first creates
232 // specific transformation matrix and pre-multiplies the current transformation by it.
233 //
234 // Current coordinate system (transformation) can be saved and restored using nvgSave() and nvgRestore().
235 
236 // Resets current transform to a identity matrix.
237 void nvgResetTransform(NVGcontext* ctx);
238 
239 // Premultiplies current coordinate system by specified matrix.
240 // The parameters are interpreted as matrix as follows:
241 //   [a c e]
242 //   [b d f]
243 //   [0 0 1]
244 void nvgTransform(NVGcontext* ctx, float a, float b, float c, float d, float e, float f);
245 
246 // Translates current coordinate system.
247 void nvgTranslate(NVGcontext* ctx, float x, float y);
248 
249 // Rotates current coordinate system. Angle is specified in radians.
250 void nvgRotate(NVGcontext* ctx, float angle);
251 
252 // Skews the current coordinate system along X axis. Angle is specified in radians.
253 void nvgSkewX(NVGcontext* ctx, float angle);
254 
255 // Skews the current coordinate system along Y axis. Angle is specified in radians.
256 void nvgSkewY(NVGcontext* ctx, float angle);
257 
258 // Scales the current coordinate system.
259 void nvgScale(NVGcontext* ctx, float x, float y);
260 
261 // Stores the top part (a-f) of the current transformation matrix in to the specified buffer.
262 //   [a c e]
263 //   [b d f]
264 //   [0 0 1]
265 // There should be space for 6 floats in the return buffer for the values a-f.
266 void nvgCurrentTransform(NVGcontext* ctx, float* xform);
267 
268 
269 // The following functions can be used to make calculations on 2x3 transformation matrices.
270 // A 2x3 matrix is represented as float[6].
271 
272 // Sets the transform to identity matrix.
273 void nvgTransformIdentity(float* dst);
274 
275 // Sets the transform to translation matrix matrix.
276 void nvgTransformTranslate(float* dst, float tx, float ty);
277 
278 // Sets the transform to scale matrix.
279 void nvgTransformScale(float* dst, float sx, float sy);
280 
281 // Sets the transform to rotate matrix. Angle is specified in radians.
282 void nvgTransformRotate(float* dst, float a);
283 
284 // Sets the transform to skew-x matrix. Angle is specified in radians.
285 void nvgTransformSkewX(float* dst, float a);
286 
287 // Sets the transform to skew-y matrix. Angle is specified in radians.
288 void nvgTransformSkewY(float* dst, float a);
289 
290 // Sets the transform to the result of multiplication of two transforms, of A = A*B.
291 void nvgTransformMultiply(float* dst, const float* src);
292 
293 // Sets the transform to the result of multiplication of two transforms, of A = B*A.
294 void nvgTransformPremultiply(float* dst, const float* src);
295 
296 // Sets the destination to inverse of specified transform.
297 // Returns 1 if the inverse could be calculated, else 0.
298 int nvgTransformInverse(float* dst, const float* src);
299 
300 // Transform a point by given transform.
301 void nvgTransformPoint(float* dstx, float* dsty, const float* xform, float srcx, float srcy);
302 
303 // Converts degrees to radians and vice versa.
304 float nvgDegToRad(float deg);
305 float nvgRadToDeg(float rad);
306 
307 //
308 // Images
309 //
310 // NanoVG allows you to load jpg, png, psd, tga, pic and gif files to be used for rendering.
311 // In addition you can upload your own image. The image loading is provided by stb_image.
312 // The parameter imageFlags is combination of flags defined in NVGimageFlags.
313 
314 // Creates image by loading it from the disk from specified file name.
315 // Returns handle to the image.
316 int nvgCreateImage(NVGcontext* ctx, const char* filename, int imageFlags);
317 
318 // Creates image by loading it from the specified chunk of memory.
319 // Returns handle to the image.
320 int nvgCreateImageMem(NVGcontext* ctx, int imageFlags, const unsigned char* data, int ndata);
321 
322 // Creates image from specified image data.
323 // Returns handle to the image.
324 int nvgCreateImageRGBA(NVGcontext* ctx, int w, int h, int imageFlags, const unsigned char* data);
325 
326 // Updates image data specified by image handle.
327 void nvgUpdateImage(NVGcontext* ctx, int image, const unsigned char* data);
328 
329 // Returns the dimensions of a created image.
330 void nvgImageSize(NVGcontext* ctx, int image, int* w, int* h);
331 
332 // Deletes created image.
333 void nvgDeleteImage(NVGcontext* ctx, int image);
334 
335 //
336 // Paints
337 //
338 // NanoVG supports four types of paints: linear gradient, box gradient, radial gradient and image pattern.
339 // These can be used as paints for strokes and fills.
340 
341 // Creates and returns a linear gradient. Parameters (sx,sy)-(ex,ey) specify the start and end coordinates
342 // of the linear gradient, icol specifies the start color and ocol the end color.
343 // The gradient is transformed by the current transform when it is passed to nvgFillPaint() or nvgStrokePaint().
344 NVGpaint nvgLinearGradient(NVGcontext* ctx, float sx, float sy, float ex, float ey,
345 						   NVGcolor icol, NVGcolor ocol);
346 
347 // Creates and returns a box gradient. Box gradient is a feathered rounded rectangle, it is useful for rendering
348 // drop shadows or highlights for boxes. Parameters (x,y) define the top-left corner of the rectangle,
349 // (w,h) define the size of the rectangle, r defines the corner radius, and f feather. Feather defines how blurry
350 // the border of the rectangle is. Parameter icol specifies the inner color and ocol the outer color of the gradient.
351 // The gradient is transformed by the current transform when it is passed to nvgFillPaint() or nvgStrokePaint().
352 NVGpaint nvgBoxGradient(NVGcontext* ctx, float x, float y, float w, float h,
353 						float r, float f, NVGcolor icol, NVGcolor ocol);
354 
355 // Creates and returns a radial gradient. Parameters (cx,cy) specify the center, inr and outr specify
356 // the inner and outer radius of the gradient, icol specifies the start color and ocol the end color.
357 // The gradient is transformed by the current transform when it is passed to nvgFillPaint() or nvgStrokePaint().
358 NVGpaint nvgRadialGradient(NVGcontext* ctx, float cx, float cy, float inr, float outr,
359 						   NVGcolor icol, NVGcolor ocol);
360 
361 // Creates and returns an image patter. Parameters (ox,oy) specify the left-top location of the image pattern,
362 // (ex,ey) the size of one image, angle rotation around the top-left corner, image is handle to the image to render.
363 // The gradient is transformed by the current transform when it is passed to nvgFillPaint() or nvgStrokePaint().
364 NVGpaint nvgImagePattern(NVGcontext* ctx, float ox, float oy, float ex, float ey,
365 						 float angle, int image, float alpha);
366 
367 //
368 // Scissoring
369 //
370 // Scissoring allows you to clip the rendering into a rectangle. This is useful for various
371 // user interface cases like rendering a text edit or a timeline.
372 
373 // Sets the current scissor rectangle.
374 // The scissor rectangle is transformed by the current transform.
375 void nvgScissor(NVGcontext* ctx, float x, float y, float w, float h);
376 
377 // Intersects current scissor rectangle with the specified rectangle.
378 // The scissor rectangle is transformed by the current transform.
379 // Note: in case the rotation of previous scissor rect differs from
380 // the current one, the intersection will be done between the specified
381 // rectangle and the previous scissor rectangle transformed in the current
382 // transform space. The resulting shape is always rectangle.
383 void nvgIntersectScissor(NVGcontext* ctx, float x, float y, float w, float h);
384 
385 // Reset and disables scissoring.
386 void nvgResetScissor(NVGcontext* ctx);
387 
388 //
389 // Paths
390 //
391 // Drawing a new shape starts with nvgBeginPath(), it clears all the currently defined paths.
392 // Then you define one or more paths and sub-paths which describe the shape. The are functions
393 // to draw common shapes like rectangles and circles, and lower level step-by-step functions,
394 // which allow to define a path curve by curve.
395 //
396 // NanoVG uses even-odd fill rule to draw the shapes. Solid shapes should have counter clockwise
397 // winding and holes should have counter clockwise order. To specify winding of a path you can
398 // call nvgPathWinding(). This is useful especially for the common shapes, which are drawn CCW.
399 //
400 // Finally you can fill the path using current fill style by calling nvgFill(), and stroke it
401 // with current stroke style by calling nvgStroke().
402 //
403 // The curve segments and sub-paths are transformed by the current transform.
404 
405 // Clears the current path and sub-paths.
406 void nvgBeginPath(NVGcontext* ctx);
407 
408 // Starts new sub-path with specified point as first point.
409 void nvgMoveTo(NVGcontext* ctx, float x, float y);
410 
411 // Adds line segment from the last point in the path to the specified point.
412 void nvgLineTo(NVGcontext* ctx, float x, float y);
413 
414 // Adds cubic bezier segment from last point in the path via two control points to the specified point.
415 void nvgBezierTo(NVGcontext* ctx, float c1x, float c1y, float c2x, float c2y, float x, float y);
416 
417 // Adds quadratic bezier segment from last point in the path via a control point to the specified point.
418 void nvgQuadTo(NVGcontext* ctx, float cx, float cy, float x, float y);
419 
420 // Adds an arc segment at the corner defined by the last path point, and two specified points.
421 void nvgArcTo(NVGcontext* ctx, float x1, float y1, float x2, float y2, float radius);
422 
423 // Closes current sub-path with a line segment.
424 void nvgClosePath(NVGcontext* ctx);
425 
426 // Sets the current sub-path winding, see NVGwinding and NVGsolidity.
427 void nvgPathWinding(NVGcontext* ctx, int dir);
428 
429 // Creates new circle arc shaped sub-path. The arc center is at cx,cy, the arc radius is r,
430 // and the arc is drawn from angle a0 to a1, and swept in direction dir (NVG_CCW, or NVG_CW).
431 // Angles are specified in radians.
432 void nvgArc(NVGcontext* ctx, float cx, float cy, float r, float a0, float a1, int dir);
433 
434 // Creates new rectangle shaped sub-path.
435 void nvgRect(NVGcontext* ctx, float x, float y, float w, float h);
436 
437 // Creates new rounded rectangle shaped sub-path.
438 void nvgRoundedRect(NVGcontext* ctx, float x, float y, float w, float h, float r);
439 
440 // Creates new ellipse shaped sub-path.
441 void nvgEllipse(NVGcontext* ctx, float cx, float cy, float rx, float ry);
442 
443 // Creates new circle shaped sub-path.
444 void nvgCircle(NVGcontext* ctx, float cx, float cy, float r);
445 
446 // Fills the current path with current fill style.
447 void nvgFill(NVGcontext* ctx);
448 
449 // Fills the current path with current stroke style.
450 void nvgStroke(NVGcontext* ctx);
451 
452 
453 //
454 // Text
455 //
456 // NanoVG allows you to load .ttf files and use the font to render text.
457 //
458 // The appearance of the text can be defined by setting the current text style
459 // and by specifying the fill color. Common text and font settings such as
460 // font size, letter spacing and text align are supported. Font blur allows you
461 // to create simple text effects such as drop shadows.
462 //
463 // At render time the font face can be set based on the font handles or name.
464 //
465 // Font measure functions return values in local space, the calculations are
466 // carried in the same resolution as the final rendering. This is done because
467 // the text glyph positions are snapped to the nearest pixels sharp rendering.
468 //
469 // The local space means that values are not rotated or scale as per the current
470 // transformation. For example if you set font size to 12, which would mean that
471 // line height is 16, then regardless of the current scaling and rotation, the
472 // returned line height is always 16. Some measures may vary because of the scaling
473 // since aforementioned pixel snapping.
474 //
475 // While this may sound a little odd, the setup allows you to always render the
476 // same way regardless of scaling. I.e. following works regardless of scaling:
477 //
478 //		const char* txt = "Text me up.";
479 //		nvgTextBounds(vg, x,y, txt, NULL, bounds);
480 //		nvgBeginPath(vg);
481 //		nvgRoundedRect(vg, bounds[0],bounds[1], bounds[2]-bounds[0], bounds[3]-bounds[1]);
482 //		nvgFill(vg);
483 //
484 // Note: currently only solid color fill is supported for text.
485 
486 // Creates font by loading it from the disk from specified file name.
487 // Returns handle to the font.
488 int nvgCreateFont(NVGcontext* ctx, const char* name, const char* filename);
489 
490 // Creates image by loading it from the specified memory chunk.
491 // Returns handle to the font.
492 int nvgCreateFontMem(NVGcontext* ctx, const char* name, const unsigned char* data, int ndata, int freeData);
493 
494 // Finds a loaded font of specified name, and returns handle to it, or -1 if the font is not found.
495 int nvgFindFont(NVGcontext* ctx, const char* name);
496 
497 // Sets the font size of current text style.
498 void nvgFontSize(NVGcontext* ctx, float size);
499 
500 // Sets the blur of current text style.
501 void nvgFontBlur(NVGcontext* ctx, float blur);
502 
503 // Sets the letter spacing of current text style.
504 void nvgTextLetterSpacing(NVGcontext* ctx, float spacing);
505 
506 // Sets the proportional line height of current text style. The line height is specified as multiple of font size.
507 void nvgTextLineHeight(NVGcontext* ctx, float lineHeight);
508 
509 // Sets the text align of current text style, see NVGalign for options.
510 void nvgTextAlign(NVGcontext* ctx, int align);
511 
512 // Sets the font face based on specified id of current text style.
513 void nvgFontFaceId(NVGcontext* ctx, int font);
514 
515 // Sets the font face based on specified name of current text style.
516 void nvgFontFace(NVGcontext* ctx, const char* font);
517 
518 // Draws text string at specified location. If end is specified only the sub-string up to the end is drawn.
519 float nvgText(NVGcontext* ctx, float x, float y, const char* string, const char* end);
520 
521 // Draws multi-line text string at specified location wrapped at the specified width. If end is specified only the sub-string up to the end is drawn.
522 // White space is stripped at the beginning of the rows, the text is split at word boundaries or when new-line characters are encountered.
523 // Words longer than the max width are slit at nearest character (i.e. no hyphenation).
524 void nvgTextBox(NVGcontext* ctx, float x, float y, float breakRowWidth, const char* string, const char* end);
525 
526 // Measures the specified text string. Parameter bounds should be a pointer to float[4],
527 // if the bounding box of the text should be returned. The bounds value are [xmin,ymin, xmax,ymax]
528 // Returns the horizontal advance of the measured text (i.e. where the next character should drawn).
529 // Measured values are returned in local coordinate space.
530 float nvgTextBounds(NVGcontext* ctx, float x, float y, const char* string, const char* end, float* bounds);
531 
532 // Measures the specified multi-text string. Parameter bounds should be a pointer to float[4],
533 // if the bounding box of the text should be returned. The bounds value are [xmin,ymin, xmax,ymax]
534 // Measured values are returned in local coordinate space.
535 void nvgTextBoxBounds(NVGcontext* ctx, float x, float y, float breakRowWidth, const char* string, const char* end, float* bounds);
536 
537 // Calculates the glyph x positions of the specified text. If end is specified only the sub-string will be used.
538 // Measured values are returned in local coordinate space.
539 int nvgTextGlyphPositions(NVGcontext* ctx, float x, float y, const char* string, const char* end, NVGglyphPosition* positions, int maxPositions);
540 
541 // Returns the vertical metrics based on the current text style.
542 // Measured values are returned in local coordinate space.
543 void nvgTextMetrics(NVGcontext* ctx, float* ascender, float* descender, float* lineh);
544 
545 // Breaks the specified text into lines. If end is specified only the sub-string will be used.
546 // White space is stripped at the beginning of the rows, the text is split at word boundaries or when new-line characters are encountered.
547 // Words longer than the max width are slit at nearest character (i.e. no hyphenation).
548 int nvgTextBreakLines(NVGcontext* ctx, const char* string, const char* end, float breakRowWidth, NVGtextRow* rows, int maxRows);
549 
550 //
551 // Internal Render API
552 //
553 enum NVGtexture {
554 	NVG_TEXTURE_ALPHA = 0x01,
555 	NVG_TEXTURE_RGBA = 0x02,
556 };
557 
558 struct NVGscissor {
559 	float xform[6];
560 	float extent[2];
561 };
562 typedef struct NVGscissor NVGscissor;
563 
564 struct NVGvertex {
565 	float x,y,u,v;
566 };
567 typedef struct NVGvertex NVGvertex;
568 
569 struct NVGpath {
570 	int first;
571 	int count;
572 	unsigned char closed;
573 	int nbevel;
574 	NVGvertex* fill;
575 	int nfill;
576 	NVGvertex* stroke;
577 	int nstroke;
578 	int winding;
579 	int convex;
580 };
581 typedef struct NVGpath NVGpath;
582 
583 struct NVGparams {
584 	void* userPtr;
585 	int edgeAntiAlias;
586 	int (*renderCreate)(void* uptr);
587 	int (*renderCreateTexture)(void* uptr, int type, int w, int h, int imageFlags, const unsigned char* data);
588 	int (*renderDeleteTexture)(void* uptr, int image);
589 	int (*renderUpdateTexture)(void* uptr, int image, int x, int y, int w, int h, const unsigned char* data);
590 	int (*renderGetTextureSize)(void* uptr, int image, int* w, int* h);
591 	void (*renderViewport)(void* uptr, int width, int height);
592 	void (*renderCancel)(void* uptr);
593 	void (*renderFlush)(void* uptr);
594 	void (*renderFill)(void* uptr, NVGpaint* paint, NVGscissor* scissor, float fringe, const float* bounds, const NVGpath* paths, int npaths);
595 	void (*renderStroke)(void* uptr, NVGpaint* paint, NVGscissor* scissor, float fringe, float strokeWidth, const NVGpath* paths, int npaths);
596 	void (*renderTriangles)(void* uptr, NVGpaint* paint, NVGscissor* scissor, const NVGvertex* verts, int nverts);
597 	void (*renderDelete)(void* uptr);
598 };
599 typedef struct NVGparams NVGparams;
600 
601 // Constructor and destructor, called by the render back-end.
602 NVGcontext* nvgCreateInternal(NVGparams* params);
603 void nvgDeleteInternal(NVGcontext* ctx);
604 
605 NVGparams* nvgInternalParams(NVGcontext* ctx);
606 
607 // Debug function to dump cached path data.
608 void nvgDebugDumpPathCache(NVGcontext* ctx);
609 
610 #ifdef _MSC_VER
611 #pragma warning(pop)
612 #endif
613 
614 #define NVG_NOTUSED(v) for (;;) { (void)(1 ? (void)0 : ( (void)(v) ) ); break; }
615 
616 #ifdef __cplusplus
617 }
618 #endif
619 
620 #endif // NANOVG_H
621