1 /*
2  * Nuklear - v1.32.0 - public domain
3  * no warrenty implied; use at your own risk.
4  * authored from 2015-2017 by Micha Mettke
5  */
6 /*
7  * ==============================================================
8  *
9  *                              API
10  *
11  * ===============================================================
12  */
13 #ifndef NK_GLFW_GL2_H_
14 #define NK_GLFW_GL2_H_
15 
16 #include <GLFW/glfw3.h>
17 
18 enum nk_glfw_init_state{
19     NK_GLFW3_DEFAULT = 0,
20     NK_GLFW3_INSTALL_CALLBACKS
21 };
22 NK_API struct nk_context*   nk_glfw3_init(GLFWwindow *win, enum nk_glfw_init_state);
23 NK_API void                 nk_glfw3_font_stash_begin(struct nk_font_atlas **atlas);
24 NK_API void                 nk_glfw3_font_stash_end(void);
25 
26 NK_API void                 nk_glfw3_new_frame(void);
27 NK_API void                 nk_glfw3_render(enum nk_anti_aliasing);
28 NK_API void                 nk_glfw3_shutdown(void);
29 
30 NK_API void                 nk_glfw3_char_callback(GLFWwindow *win, unsigned int codepoint);
31 NK_API void                 nk_gflw3_scroll_callback(GLFWwindow *win, double xoff, double yoff);
32 
33 #endif
34 
35 /*
36  * ==============================================================
37  *
38  *                          IMPLEMENTATION
39  *
40  * ===============================================================
41  */
42 #ifdef NK_GLFW_GL2_IMPLEMENTATION
43 
44 #ifndef NK_GLFW_TEXT_MAX
45 #define NK_GLFW_TEXT_MAX 256
46 #endif
47 #ifndef NK_GLFW_DOUBLE_CLICK_LO
48 #define NK_GLFW_DOUBLE_CLICK_LO 0.02
49 #endif
50 #ifndef NK_GLFW_DOUBLE_CLICK_HI
51 #define NK_GLFW_DOUBLE_CLICK_HI 0.2
52 #endif
53 
54 struct nk_glfw_device {
55     struct nk_buffer cmds;
56     struct nk_draw_null_texture null;
57     GLuint font_tex;
58 };
59 
60 struct nk_glfw_vertex {
61     float position[2];
62     float uv[2];
63     nk_byte col[4];
64 };
65 
66 static struct nk_glfw {
67     GLFWwindow *win;
68     int width, height;
69     int display_width, display_height;
70     struct nk_glfw_device ogl;
71     struct nk_context ctx;
72     struct nk_font_atlas atlas;
73     struct nk_vec2 fb_scale;
74     unsigned int text[NK_GLFW_TEXT_MAX];
75     int text_len;
76     struct nk_vec2 scroll;
77     double last_button_click;
78     int is_double_click_down;
79     struct nk_vec2 double_click_pos;
80 } glfw;
81 
82 NK_INTERN void
nk_glfw3_device_upload_atlas(const void * image,int width,int height)83 nk_glfw3_device_upload_atlas(const void *image, int width, int height)
84 {
85     struct nk_glfw_device *dev = &glfw.ogl;
86     glGenTextures(1, &dev->font_tex);
87     glBindTexture(GL_TEXTURE_2D, dev->font_tex);
88     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
89     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
90     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (GLsizei)width, (GLsizei)height, 0,
91                 GL_RGBA, GL_UNSIGNED_BYTE, image);
92 }
93 
94 NK_API void
nk_glfw3_render(enum nk_anti_aliasing AA)95 nk_glfw3_render(enum nk_anti_aliasing AA)
96 {
97     /* setup global state */
98     struct nk_glfw_device *dev = &glfw.ogl;
99     glPushAttrib(GL_ENABLE_BIT|GL_COLOR_BUFFER_BIT|GL_TRANSFORM_BIT);
100     glDisable(GL_CULL_FACE);
101     glDisable(GL_DEPTH_TEST);
102     glEnable(GL_SCISSOR_TEST);
103     glEnable(GL_BLEND);
104     glEnable(GL_TEXTURE_2D);
105     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
106 
107     /* setup viewport/project */
108     glViewport(0,0,(GLsizei)glfw.display_width,(GLsizei)glfw.display_height);
109     glMatrixMode(GL_PROJECTION);
110     glPushMatrix();
111     glLoadIdentity();
112     glOrtho(0.0f, glfw.width, glfw.height, 0.0f, -1.0f, 1.0f);
113     glMatrixMode(GL_MODELVIEW);
114     glPushMatrix();
115     glLoadIdentity();
116 
117     glEnableClientState(GL_VERTEX_ARRAY);
118     glEnableClientState(GL_TEXTURE_COORD_ARRAY);
119     glEnableClientState(GL_COLOR_ARRAY);
120     {
121         GLsizei vs = sizeof(struct nk_glfw_vertex);
122         size_t vp = offsetof(struct nk_glfw_vertex, position);
123         size_t vt = offsetof(struct nk_glfw_vertex, uv);
124         size_t vc = offsetof(struct nk_glfw_vertex, col);
125 
126         /* convert from command queue into draw list and draw to screen */
127         const struct nk_draw_command *cmd;
128         const nk_draw_index *offset = NULL;
129         struct nk_buffer vbuf, ebuf;
130 
131         /* fill convert configuration */
132         struct nk_convert_config config;
133         static const struct nk_draw_vertex_layout_element vertex_layout[] = {
134             {NK_VERTEX_POSITION, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_glfw_vertex, position)},
135             {NK_VERTEX_TEXCOORD, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_glfw_vertex, uv)},
136             {NK_VERTEX_COLOR, NK_FORMAT_R8G8B8A8, NK_OFFSETOF(struct nk_glfw_vertex, col)},
137             {NK_VERTEX_LAYOUT_END}
138         };
139         NK_MEMSET(&config, 0, sizeof(config));
140         config.vertex_layout = vertex_layout;
141         config.vertex_size = sizeof(struct nk_glfw_vertex);
142         config.vertex_alignment = NK_ALIGNOF(struct nk_glfw_vertex);
143         config.null = dev->null;
144         config.circle_segment_count = 22;
145         config.curve_segment_count = 22;
146         config.arc_segment_count = 22;
147         config.global_alpha = 1.0f;
148         config.shape_AA = AA;
149         config.line_AA = AA;
150 
151         /* convert shapes into vertexes */
152         nk_buffer_init_default(&vbuf);
153         nk_buffer_init_default(&ebuf);
154         nk_convert(&glfw.ctx, &dev->cmds, &vbuf, &ebuf, &config);
155 
156         /* setup vertex buffer pointer */
157         {const void *vertices = nk_buffer_memory_const(&vbuf);
158         glVertexPointer(2, GL_FLOAT, vs, (const void*)((const nk_byte*)vertices + vp));
159         glTexCoordPointer(2, GL_FLOAT, vs, (const void*)((const nk_byte*)vertices + vt));
160         glColorPointer(4, GL_UNSIGNED_BYTE, vs, (const void*)((const nk_byte*)vertices + vc));}
161 
162         /* iterate over and execute each draw command */
163         offset = (const nk_draw_index*)nk_buffer_memory_const(&ebuf);
164         nk_draw_foreach(cmd, &glfw.ctx, &dev->cmds)
165         {
166             if (!cmd->elem_count) continue;
167             glBindTexture(GL_TEXTURE_2D, (GLuint)cmd->texture.id);
168             glScissor(
169                 (GLint)(cmd->clip_rect.x * glfw.fb_scale.x),
170                 (GLint)((glfw.height - (GLint)(cmd->clip_rect.y + cmd->clip_rect.h)) * glfw.fb_scale.y),
171                 (GLint)(cmd->clip_rect.w * glfw.fb_scale.x),
172                 (GLint)(cmd->clip_rect.h * glfw.fb_scale.y));
173             glDrawElements(GL_TRIANGLES, (GLsizei)cmd->elem_count, GL_UNSIGNED_SHORT, offset);
174             offset += cmd->elem_count;
175         }
176         nk_clear(&glfw.ctx);
177         nk_buffer_free(&vbuf);
178         nk_buffer_free(&ebuf);
179     }
180 
181     /* default OpenGL state */
182     glDisableClientState(GL_VERTEX_ARRAY);
183     glDisableClientState(GL_TEXTURE_COORD_ARRAY);
184     glDisableClientState(GL_COLOR_ARRAY);
185 
186     glDisable(GL_CULL_FACE);
187     glDisable(GL_DEPTH_TEST);
188     glDisable(GL_SCISSOR_TEST);
189     glDisable(GL_BLEND);
190     glDisable(GL_TEXTURE_2D);
191 
192     glBindTexture(GL_TEXTURE_2D, 0);
193     glMatrixMode(GL_MODELVIEW);
194     glPopMatrix();
195     glMatrixMode(GL_PROJECTION);
196     glPopMatrix();
197     glPopAttrib();
198 }
199 
200 NK_API void
nk_glfw3_char_callback(GLFWwindow * win,unsigned int codepoint)201 nk_glfw3_char_callback(GLFWwindow *win, unsigned int codepoint)
202 {
203     (void)win;
204     if (glfw.text_len < NK_GLFW_TEXT_MAX)
205         glfw.text[glfw.text_len++] = codepoint;
206 }
207 
208 NK_API void
nk_gflw3_scroll_callback(GLFWwindow * win,double xoff,double yoff)209 nk_gflw3_scroll_callback(GLFWwindow *win, double xoff, double yoff)
210 {
211     (void)win; (void)xoff;
212     glfw.scroll.x += (float)xoff;
213     glfw.scroll.y += (float)yoff;
214 }
215 
216 NK_API void
nk_glfw3_mouse_button_callback(GLFWwindow * window,int button,int action,int mods)217 nk_glfw3_mouse_button_callback(GLFWwindow* window, int button, int action, int mods)
218 {
219     double x, y;
220     if (button != GLFW_MOUSE_BUTTON_LEFT) return;
221     glfwGetCursorPos(window, &x, &y);
222     if (action == GLFW_PRESS)  {
223         double dt = glfwGetTime() - glfw.last_button_click;
224         if (dt > NK_GLFW_DOUBLE_CLICK_LO && dt < NK_GLFW_DOUBLE_CLICK_HI) {
225             glfw.is_double_click_down = nk_true;
226             glfw.double_click_pos = nk_vec2((float)x, (float)y);
227         }
228         glfw.last_button_click = glfwGetTime();
229     } else glfw.is_double_click_down = nk_false;
230 }
231 
232 NK_INTERN void
nk_glfw3_clipbard_paste(nk_handle usr,struct nk_text_edit * edit)233 nk_glfw3_clipbard_paste(nk_handle usr, struct nk_text_edit *edit)
234 {
235     const char *text = glfwGetClipboardString(glfw.win);
236     if (text) nk_textedit_paste(edit, text, nk_strlen(text));
237     (void)usr;
238 }
239 
240 NK_INTERN void
nk_glfw3_clipbard_copy(nk_handle usr,const char * text,int len)241 nk_glfw3_clipbard_copy(nk_handle usr, const char *text, int len)
242 {
243     char *str = 0;
244     (void)usr;
245     if (!len) return;
246     str = (char*)malloc((size_t)len+1);
247     if (!str) return;
248     NK_MEMCPY(str, text, (size_t)len);
249     str[len] = '\0';
250     glfwSetClipboardString(glfw.win, str);
251     free(str);
252 }
253 
254 NK_API struct nk_context*
nk_glfw3_init(GLFWwindow * win,enum nk_glfw_init_state init_state)255 nk_glfw3_init(GLFWwindow *win, enum nk_glfw_init_state init_state)
256 {
257     glfw.win = win;
258     if (init_state == NK_GLFW3_INSTALL_CALLBACKS) {
259         glfwSetScrollCallback(win, nk_gflw3_scroll_callback);
260         glfwSetCharCallback(win, nk_glfw3_char_callback);
261         glfwSetMouseButtonCallback(win, nk_glfw3_mouse_button_callback);
262     }
263     nk_init_default(&glfw.ctx, 0);
264     glfw.ctx.clip.copy = nk_glfw3_clipbard_copy;
265     glfw.ctx.clip.paste = nk_glfw3_clipbard_paste;
266     glfw.ctx.clip.userdata = nk_handle_ptr(0);
267     nk_buffer_init_default(&glfw.ogl.cmds);
268 
269     glfw.is_double_click_down = nk_false;
270     glfw.double_click_pos = nk_vec2(0, 0);
271 
272     return &glfw.ctx;
273 }
274 
275 NK_API void
nk_glfw3_font_stash_begin(struct nk_font_atlas ** atlas)276 nk_glfw3_font_stash_begin(struct nk_font_atlas **atlas)
277 {
278     nk_font_atlas_init_default(&glfw.atlas);
279     nk_font_atlas_begin(&glfw.atlas);
280     *atlas = &glfw.atlas;
281 }
282 
283 NK_API void
nk_glfw3_font_stash_end(void)284 nk_glfw3_font_stash_end(void)
285 {
286     const void *image; int w, h;
287     image = nk_font_atlas_bake(&glfw.atlas, &w, &h, NK_FONT_ATLAS_RGBA32);
288     nk_glfw3_device_upload_atlas(image, w, h);
289     nk_font_atlas_end(&glfw.atlas, nk_handle_id((int)glfw.ogl.font_tex), &glfw.ogl.null);
290     if (glfw.atlas.default_font)
291         nk_style_set_font(&glfw.ctx, &glfw.atlas.default_font->handle);
292 }
293 
294 NK_API void
nk_glfw3_new_frame(void)295 nk_glfw3_new_frame(void)
296 {
297     int i;
298     double x, y;
299     struct nk_context *ctx = &glfw.ctx;
300     struct GLFWwindow *win = glfw.win;
301 
302     glfwGetWindowSize(win, &glfw.width, &glfw.height);
303     glfwGetFramebufferSize(win, &glfw.display_width, &glfw.display_height);
304     glfw.fb_scale.x = (float)glfw.display_width/(float)glfw.width;
305     glfw.fb_scale.y = (float)glfw.display_height/(float)glfw.height;
306 
307     nk_input_begin(ctx);
308     for (i = 0; i < glfw.text_len; ++i)
309         nk_input_unicode(ctx, glfw.text[i]);
310 
311     /* optional grabbing behavior */
312     if (ctx->input.mouse.grab)
313         glfwSetInputMode(glfw.win, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
314     else if (ctx->input.mouse.ungrab)
315         glfwSetInputMode(glfw.win, GLFW_CURSOR, GLFW_CURSOR_NORMAL);
316 
317     nk_input_key(ctx, NK_KEY_DEL, glfwGetKey(win, GLFW_KEY_DELETE) == GLFW_PRESS);
318     nk_input_key(ctx, NK_KEY_ENTER, glfwGetKey(win, GLFW_KEY_ENTER) == GLFW_PRESS);
319     nk_input_key(ctx, NK_KEY_TAB, glfwGetKey(win, GLFW_KEY_TAB) == GLFW_PRESS);
320     nk_input_key(ctx, NK_KEY_BACKSPACE, glfwGetKey(win, GLFW_KEY_BACKSPACE) == GLFW_PRESS);
321     nk_input_key(ctx, NK_KEY_UP, glfwGetKey(win, GLFW_KEY_UP) == GLFW_PRESS);
322     nk_input_key(ctx, NK_KEY_DOWN, glfwGetKey(win, GLFW_KEY_DOWN) == GLFW_PRESS);
323     nk_input_key(ctx, NK_KEY_TEXT_START, glfwGetKey(win, GLFW_KEY_HOME) == GLFW_PRESS);
324     nk_input_key(ctx, NK_KEY_TEXT_END, glfwGetKey(win, GLFW_KEY_END) == GLFW_PRESS);
325     nk_input_key(ctx, NK_KEY_SCROLL_START, glfwGetKey(win, GLFW_KEY_HOME) == GLFW_PRESS);
326     nk_input_key(ctx, NK_KEY_SCROLL_END, glfwGetKey(win, GLFW_KEY_END) == GLFW_PRESS);
327     nk_input_key(ctx, NK_KEY_SCROLL_DOWN, glfwGetKey(win, GLFW_KEY_PAGE_DOWN) == GLFW_PRESS);
328     nk_input_key(ctx, NK_KEY_SCROLL_UP, glfwGetKey(win, GLFW_KEY_PAGE_UP) == GLFW_PRESS);
329     nk_input_key(ctx, NK_KEY_SHIFT, glfwGetKey(win, GLFW_KEY_LEFT_SHIFT) == GLFW_PRESS||
330                                     glfwGetKey(win, GLFW_KEY_RIGHT_SHIFT) == GLFW_PRESS);
331 
332     if (glfwGetKey(win, GLFW_KEY_LEFT_CONTROL) == GLFW_PRESS ||
333         glfwGetKey(win, GLFW_KEY_RIGHT_CONTROL) == GLFW_PRESS) {
334         nk_input_key(ctx, NK_KEY_COPY, glfwGetKey(win, GLFW_KEY_C) == GLFW_PRESS);
335         nk_input_key(ctx, NK_KEY_PASTE, glfwGetKey(win, GLFW_KEY_V) == GLFW_PRESS);
336         nk_input_key(ctx, NK_KEY_CUT, glfwGetKey(win, GLFW_KEY_X) == GLFW_PRESS);
337         nk_input_key(ctx, NK_KEY_TEXT_UNDO, glfwGetKey(win, GLFW_KEY_Z) == GLFW_PRESS);
338         nk_input_key(ctx, NK_KEY_TEXT_REDO, glfwGetKey(win, GLFW_KEY_R) == GLFW_PRESS);
339         nk_input_key(ctx, NK_KEY_TEXT_WORD_LEFT, glfwGetKey(win, GLFW_KEY_LEFT) == GLFW_PRESS);
340         nk_input_key(ctx, NK_KEY_TEXT_WORD_RIGHT, glfwGetKey(win, GLFW_KEY_RIGHT) == GLFW_PRESS);
341         nk_input_key(ctx, NK_KEY_TEXT_LINE_START, glfwGetKey(win, GLFW_KEY_B) == GLFW_PRESS);
342         nk_input_key(ctx, NK_KEY_TEXT_LINE_END, glfwGetKey(win, GLFW_KEY_E) == GLFW_PRESS);
343     } else {
344         nk_input_key(ctx, NK_KEY_LEFT, glfwGetKey(win, GLFW_KEY_LEFT) == GLFW_PRESS);
345         nk_input_key(ctx, NK_KEY_RIGHT, glfwGetKey(win, GLFW_KEY_RIGHT) == GLFW_PRESS);
346         nk_input_key(ctx, NK_KEY_COPY, 0);
347         nk_input_key(ctx, NK_KEY_PASTE, 0);
348         nk_input_key(ctx, NK_KEY_CUT, 0);
349         nk_input_key(ctx, NK_KEY_SHIFT, 0);
350     }
351 
352     glfwGetCursorPos(win, &x, &y);
353     nk_input_motion(ctx, (int)x, (int)y);
354     if (ctx->input.mouse.grabbed) {
355         glfwSetCursorPos(glfw.win, (double)ctx->input.mouse.prev.x, (double)ctx->input.mouse.prev.y);
356         ctx->input.mouse.pos.x = ctx->input.mouse.prev.x;
357         ctx->input.mouse.pos.y = ctx->input.mouse.prev.y;
358     }
359 
360     nk_input_button(ctx, NK_BUTTON_LEFT, (int)x, (int)y, glfwGetMouseButton(win, GLFW_MOUSE_BUTTON_LEFT) == GLFW_PRESS);
361     nk_input_button(ctx, NK_BUTTON_MIDDLE, (int)x, (int)y, glfwGetMouseButton(win, GLFW_MOUSE_BUTTON_MIDDLE) == GLFW_PRESS);
362     nk_input_button(ctx, NK_BUTTON_RIGHT, (int)x, (int)y, glfwGetMouseButton(win, GLFW_MOUSE_BUTTON_RIGHT) == GLFW_PRESS);
363     nk_input_button(ctx, NK_BUTTON_DOUBLE, (int)glfw.double_click_pos.x, (int)glfw.double_click_pos.y, glfw.is_double_click_down);
364     nk_input_scroll(ctx, glfw.scroll);
365     nk_input_end(&glfw.ctx);
366     glfw.text_len = 0;
367     glfw.scroll = nk_vec2(0,0);
368 }
369 
370 NK_API
nk_glfw3_shutdown(void)371 void nk_glfw3_shutdown(void)
372 {
373     struct nk_glfw_device *dev = &glfw.ogl;
374     nk_font_atlas_clear(&glfw.atlas);
375     nk_free(&glfw.ctx);
376     glDeleteTextures(1, &dev->font_tex);
377     nk_buffer_free(&dev->cmds);
378     NK_MEMSET(&glfw, 0, sizeof(glfw));
379 }
380 
381 #endif
382