1 /*
2 * Nuklear - 1.40.8 - public domain
3 * no warrenty implied; use at your own risk.
4 * authored from 2015-2017 by Micha Mettke
5 * emscripten from 2016 by Chris Willcocks
6 * OpenGL ES 2.0 from 2017 by Dmitry Hrabrov a.k.a. DeXPeriX
7 */
8 /*
9 * ==============================================================
10 *
11 * API
12 *
13 * ===============================================================
14 */
15 #ifndef NK_SDL_GLES2_H_
16 #define NK_SDL_GLES2_H_
17
18 #include <SDL2/SDL.h>
19 #include <SDL2/SDL_opengles2.h>
20
21
22 NK_API struct nk_context* nk_sdl_init(SDL_Window *win);
23 NK_API void nk_sdl_font_stash_begin(struct nk_font_atlas **atlas);
24 NK_API void nk_sdl_font_stash_end(void);
25 NK_API int nk_sdl_handle_event(SDL_Event *evt);
26 NK_API void nk_sdl_render(enum nk_anti_aliasing , int max_vertex_buffer, int max_element_buffer);
27 NK_API void nk_sdl_shutdown(void);
28 NK_API void nk_sdl_device_destroy(void);
29 NK_API void nk_sdl_device_create(void);
30
31 #endif
32
33 /*
34 * ==============================================================
35 *
36 * IMPLEMENTATION
37 *
38 * ===============================================================
39 */
40 #ifdef NK_SDL_GLES2_IMPLEMENTATION
41
42 #include <string.h>
43
44 struct nk_sdl_device {
45 struct nk_buffer cmds;
46 struct nk_draw_null_texture null;
47 GLuint vbo, ebo;
48 GLuint prog;
49 GLuint vert_shdr;
50 GLuint frag_shdr;
51 GLint attrib_pos;
52 GLint attrib_uv;
53 GLint attrib_col;
54 GLint uniform_tex;
55 GLint uniform_proj;
56 GLuint font_tex;
57 GLsizei vs;
58 size_t vp, vt, vc;
59 };
60
61 struct nk_sdl_vertex {
62 GLfloat position[2];
63 GLfloat uv[2];
64 nk_byte col[4];
65 };
66
67 static struct nk_sdl {
68 SDL_Window *win;
69 struct nk_sdl_device ogl;
70 struct nk_context ctx;
71 struct nk_font_atlas atlas;
72 } sdl;
73
74
75 #define NK_SHADER_VERSION "#version 100\n"
76
77
78 NK_API void
nk_sdl_device_create(void)79 nk_sdl_device_create(void)
80 {
81 GLint status;
82 static const GLchar *vertex_shader =
83 NK_SHADER_VERSION
84 "uniform mat4 ProjMtx;\n"
85 "attribute vec2 Position;\n"
86 "attribute vec2 TexCoord;\n"
87 "attribute vec4 Color;\n"
88 "varying vec2 Frag_UV;\n"
89 "varying vec4 Frag_Color;\n"
90 "void main() {\n"
91 " Frag_UV = TexCoord;\n"
92 " Frag_Color = Color;\n"
93 " gl_Position = ProjMtx * vec4(Position.xy, 0, 1);\n"
94 "}\n";
95 static const GLchar *fragment_shader =
96 NK_SHADER_VERSION
97 "precision mediump float;\n"
98 "uniform sampler2D Texture;\n"
99 "varying vec2 Frag_UV;\n"
100 "varying vec4 Frag_Color;\n"
101 "void main(){\n"
102 " gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV);\n"
103 "}\n";
104
105 struct nk_sdl_device *dev = &sdl.ogl;
106
107 nk_buffer_init_default(&dev->cmds);
108 dev->prog = glCreateProgram();
109 dev->vert_shdr = glCreateShader(GL_VERTEX_SHADER);
110 dev->frag_shdr = glCreateShader(GL_FRAGMENT_SHADER);
111 glShaderSource(dev->vert_shdr, 1, &vertex_shader, 0);
112 glShaderSource(dev->frag_shdr, 1, &fragment_shader, 0);
113 glCompileShader(dev->vert_shdr);
114 glCompileShader(dev->frag_shdr);
115 glGetShaderiv(dev->vert_shdr, GL_COMPILE_STATUS, &status);
116 assert(status == GL_TRUE);
117 glGetShaderiv(dev->frag_shdr, GL_COMPILE_STATUS, &status);
118 assert(status == GL_TRUE);
119 glAttachShader(dev->prog, dev->vert_shdr);
120 glAttachShader(dev->prog, dev->frag_shdr);
121 glLinkProgram(dev->prog);
122 glGetProgramiv(dev->prog, GL_LINK_STATUS, &status);
123 assert(status == GL_TRUE);
124
125
126 dev->uniform_tex = glGetUniformLocation(dev->prog, "Texture");
127 dev->uniform_proj = glGetUniformLocation(dev->prog, "ProjMtx");
128 dev->attrib_pos = glGetAttribLocation(dev->prog, "Position");
129 dev->attrib_uv = glGetAttribLocation(dev->prog, "TexCoord");
130 dev->attrib_col = glGetAttribLocation(dev->prog, "Color");
131 {
132 dev->vs = sizeof(struct nk_sdl_vertex);
133 dev->vp = offsetof(struct nk_sdl_vertex, position);
134 dev->vt = offsetof(struct nk_sdl_vertex, uv);
135 dev->vc = offsetof(struct nk_sdl_vertex, col);
136
137 /* Allocate buffers */
138 glGenBuffers(1, &dev->vbo);
139 glGenBuffers(1, &dev->ebo);
140 }
141 glBindTexture(GL_TEXTURE_2D, 0);
142 glBindBuffer(GL_ARRAY_BUFFER, 0);
143 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
144 }
145
146 NK_INTERN void
nk_sdl_device_upload_atlas(const void * image,int width,int height)147 nk_sdl_device_upload_atlas(const void *image, int width, int height)
148 {
149 struct nk_sdl_device *dev = &sdl.ogl;
150 glGenTextures(1, &dev->font_tex);
151 glBindTexture(GL_TEXTURE_2D, dev->font_tex);
152 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
153 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
154 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (GLsizei)width, (GLsizei)height, 0,
155 GL_RGBA, GL_UNSIGNED_BYTE, image);
156 }
157
158 NK_API void
nk_sdl_device_destroy(void)159 nk_sdl_device_destroy(void)
160 {
161 struct nk_sdl_device *dev = &sdl.ogl;
162 glDetachShader(dev->prog, dev->vert_shdr);
163 glDetachShader(dev->prog, dev->frag_shdr);
164 glDeleteShader(dev->vert_shdr);
165 glDeleteShader(dev->frag_shdr);
166 glDeleteProgram(dev->prog);
167 glDeleteTextures(1, &dev->font_tex);
168 glDeleteBuffers(1, &dev->vbo);
169 glDeleteBuffers(1, &dev->ebo);
170 nk_buffer_free(&dev->cmds);
171 }
172
173 NK_API void
nk_sdl_render(enum nk_anti_aliasing AA,int max_vertex_buffer,int max_element_buffer)174 nk_sdl_render(enum nk_anti_aliasing AA, int max_vertex_buffer, int max_element_buffer)
175 {
176 struct nk_sdl_device *dev = &sdl.ogl;
177 int width, height;
178 int display_width, display_height;
179 struct nk_vec2 scale;
180 GLfloat ortho[4][4] = {
181 {2.0f, 0.0f, 0.0f, 0.0f},
182 {0.0f,-2.0f, 0.0f, 0.0f},
183 {0.0f, 0.0f,-1.0f, 0.0f},
184 {-1.0f,1.0f, 0.0f, 1.0f},
185 };
186 SDL_GetWindowSize(sdl.win, &width, &height);
187 SDL_GL_GetDrawableSize(sdl.win, &display_width, &display_height);
188 ortho[0][0] /= (GLfloat)width;
189 ortho[1][1] /= (GLfloat)height;
190
191 scale.x = (float)display_width/(float)width;
192 scale.y = (float)display_height/(float)height;
193
194 /* setup global state */
195 glViewport(0,0,display_width,display_height);
196 glEnable(GL_BLEND);
197 glBlendEquation(GL_FUNC_ADD);
198 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
199 glDisable(GL_CULL_FACE);
200 glDisable(GL_DEPTH_TEST);
201 glEnable(GL_SCISSOR_TEST);
202 glActiveTexture(GL_TEXTURE0);
203
204 /* setup program */
205 glUseProgram(dev->prog);
206 glUniform1i(dev->uniform_tex, 0);
207 glUniformMatrix4fv(dev->uniform_proj, 1, GL_FALSE, &ortho[0][0]);
208 {
209 /* convert from command queue into draw list and draw to screen */
210 const struct nk_draw_command *cmd;
211 void *vertices, *elements;
212 const nk_draw_index *offset = NULL;
213
214 /* Bind buffers */
215 glBindBuffer(GL_ARRAY_BUFFER, dev->vbo);
216 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, dev->ebo);
217
218 {
219 /* buffer setup */
220 glEnableVertexAttribArray((GLuint)dev->attrib_pos);
221 glEnableVertexAttribArray((GLuint)dev->attrib_uv);
222 glEnableVertexAttribArray((GLuint)dev->attrib_col);
223
224 glVertexAttribPointer((GLuint)dev->attrib_pos, 2, GL_FLOAT, GL_FALSE, dev->vs, (void*)dev->vp);
225 glVertexAttribPointer((GLuint)dev->attrib_uv, 2, GL_FLOAT, GL_FALSE, dev->vs, (void*)dev->vt);
226 glVertexAttribPointer((GLuint)dev->attrib_col, 4, GL_UNSIGNED_BYTE, GL_TRUE, dev->vs, (void*)dev->vc);
227 }
228
229 glBufferData(GL_ARRAY_BUFFER, max_vertex_buffer, NULL, GL_STREAM_DRAW);
230 glBufferData(GL_ELEMENT_ARRAY_BUFFER, max_element_buffer, NULL, GL_STREAM_DRAW);
231
232 /* load vertices/elements directly into vertex/element buffer */
233 vertices = malloc((size_t)max_vertex_buffer);
234 elements = malloc((size_t)max_element_buffer);
235 {
236 /* fill convert configuration */
237 struct nk_convert_config config;
238 static const struct nk_draw_vertex_layout_element vertex_layout[] = {
239 {NK_VERTEX_POSITION, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_sdl_vertex, position)},
240 {NK_VERTEX_TEXCOORD, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_sdl_vertex, uv)},
241 {NK_VERTEX_COLOR, NK_FORMAT_R8G8B8A8, NK_OFFSETOF(struct nk_sdl_vertex, col)},
242 {NK_VERTEX_LAYOUT_END}
243 };
244 memset(&config, 0, sizeof(config));
245 config.vertex_layout = vertex_layout;
246 config.vertex_size = sizeof(struct nk_sdl_vertex);
247 config.vertex_alignment = NK_ALIGNOF(struct nk_sdl_vertex);
248 config.null = dev->null;
249 config.circle_segment_count = 22;
250 config.curve_segment_count = 22;
251 config.arc_segment_count = 22;
252 config.global_alpha = 1.0f;
253 config.shape_AA = AA;
254 config.line_AA = AA;
255
256 /* setup buffers to load vertices and elements */
257 {struct nk_buffer vbuf, ebuf;
258 nk_buffer_init_fixed(&vbuf, vertices, (nk_size)max_vertex_buffer);
259 nk_buffer_init_fixed(&ebuf, elements, (nk_size)max_element_buffer);
260 nk_convert(&sdl.ctx, &dev->cmds, &vbuf, &ebuf, &config);}
261 }
262 glBufferSubData(GL_ARRAY_BUFFER, 0, (size_t)max_vertex_buffer, vertices);
263 glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, (size_t)max_element_buffer, elements);
264 free(vertices);
265 free(elements);
266
267 /* iterate over and execute each draw command */
268 nk_draw_foreach(cmd, &sdl.ctx, &dev->cmds) {
269 if (!cmd->elem_count) continue;
270 glBindTexture(GL_TEXTURE_2D, (GLuint)cmd->texture.id);
271 glScissor((GLint)(cmd->clip_rect.x * scale.x),
272 (GLint)((height - (GLint)(cmd->clip_rect.y + cmd->clip_rect.h)) * scale.y),
273 (GLint)(cmd->clip_rect.w * scale.x),
274 (GLint)(cmd->clip_rect.h * scale.y));
275 glDrawElements(GL_TRIANGLES, (GLsizei)cmd->elem_count, GL_UNSIGNED_SHORT, offset);
276 offset += cmd->elem_count;
277 }
278 nk_clear(&sdl.ctx);
279 nk_buffer_clear(&dev->cmds);
280 }
281
282 glUseProgram(0);
283 glBindBuffer(GL_ARRAY_BUFFER, 0);
284 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
285
286 glDisable(GL_BLEND);
287 glDisable(GL_SCISSOR_TEST);
288 }
289
290 static void
nk_sdl_clipboard_paste(nk_handle usr,struct nk_text_edit * edit)291 nk_sdl_clipboard_paste(nk_handle usr, struct nk_text_edit *edit)
292 {
293 const char *text = SDL_GetClipboardText();
294 if (text) nk_textedit_paste(edit, text, nk_strlen(text));
295 (void)usr;
296 }
297
298 static void
nk_sdl_clipboard_copy(nk_handle usr,const char * text,int len)299 nk_sdl_clipboard_copy(nk_handle usr, const char *text, int len)
300 {
301 char *str = 0;
302 (void)usr;
303 if (!len) return;
304 str = (char*)malloc((size_t)len+1);
305 if (!str) return;
306 memcpy(str, text, (size_t)len);
307 str[len] = '\0';
308 SDL_SetClipboardText(str);
309 free(str);
310 }
311
312 NK_API struct nk_context*
nk_sdl_init(SDL_Window * win)313 nk_sdl_init(SDL_Window *win)
314 {
315 sdl.win = win;
316 nk_init_default(&sdl.ctx, 0);
317 sdl.ctx.clip.copy = nk_sdl_clipboard_copy;
318 sdl.ctx.clip.paste = nk_sdl_clipboard_paste;
319 sdl.ctx.clip.userdata = nk_handle_ptr(0);
320 nk_sdl_device_create();
321 return &sdl.ctx;
322 }
323
324 NK_API void
nk_sdl_font_stash_begin(struct nk_font_atlas ** atlas)325 nk_sdl_font_stash_begin(struct nk_font_atlas **atlas)
326 {
327 nk_font_atlas_init_default(&sdl.atlas);
328 nk_font_atlas_begin(&sdl.atlas);
329 *atlas = &sdl.atlas;
330 }
331
332 NK_API void
nk_sdl_font_stash_end(void)333 nk_sdl_font_stash_end(void)
334 {
335 const void *image; int w, h;
336 image = nk_font_atlas_bake(&sdl.atlas, &w, &h, NK_FONT_ATLAS_RGBA32);
337 nk_sdl_device_upload_atlas(image, w, h);
338 nk_font_atlas_end(&sdl.atlas, nk_handle_id((int)sdl.ogl.font_tex), &sdl.ogl.null);
339 if (sdl.atlas.default_font)
340 nk_style_set_font(&sdl.ctx, &sdl.atlas.default_font->handle);
341
342 }
343
344 NK_API int
nk_sdl_handle_event(SDL_Event * evt)345 nk_sdl_handle_event(SDL_Event *evt)
346 {
347 struct nk_context *ctx = &sdl.ctx;
348 if (evt->type == SDL_KEYUP || evt->type == SDL_KEYDOWN) {
349 /* key events */
350 int down = evt->type == SDL_KEYDOWN;
351 const Uint8* state = SDL_GetKeyboardState(0);
352 SDL_Keycode sym = evt->key.keysym.sym;
353 if (sym == SDLK_RSHIFT || sym == SDLK_LSHIFT)
354 nk_input_key(ctx, NK_KEY_SHIFT, down);
355 else if (sym == SDLK_DELETE)
356 nk_input_key(ctx, NK_KEY_DEL, down);
357 else if (sym == SDLK_RETURN)
358 nk_input_key(ctx, NK_KEY_ENTER, down);
359 else if (sym == SDLK_TAB)
360 nk_input_key(ctx, NK_KEY_TAB, down);
361 else if (sym == SDLK_BACKSPACE)
362 nk_input_key(ctx, NK_KEY_BACKSPACE, down);
363 else if (sym == SDLK_HOME) {
364 nk_input_key(ctx, NK_KEY_TEXT_START, down);
365 nk_input_key(ctx, NK_KEY_SCROLL_START, down);
366 } else if (sym == SDLK_END) {
367 nk_input_key(ctx, NK_KEY_TEXT_END, down);
368 nk_input_key(ctx, NK_KEY_SCROLL_END, down);
369 } else if (sym == SDLK_PAGEDOWN) {
370 nk_input_key(ctx, NK_KEY_SCROLL_DOWN, down);
371 } else if (sym == SDLK_PAGEUP) {
372 nk_input_key(ctx, NK_KEY_SCROLL_UP, down);
373 } else if (sym == SDLK_z)
374 nk_input_key(ctx, NK_KEY_TEXT_UNDO, down && state[SDL_SCANCODE_LCTRL]);
375 else if (sym == SDLK_r)
376 nk_input_key(ctx, NK_KEY_TEXT_REDO, down && state[SDL_SCANCODE_LCTRL]);
377 else if (sym == SDLK_c)
378 nk_input_key(ctx, NK_KEY_COPY, down && state[SDL_SCANCODE_LCTRL]);
379 else if (sym == SDLK_v)
380 nk_input_key(ctx, NK_KEY_PASTE, down && state[SDL_SCANCODE_LCTRL]);
381 else if (sym == SDLK_x)
382 nk_input_key(ctx, NK_KEY_CUT, down && state[SDL_SCANCODE_LCTRL]);
383 else if (sym == SDLK_b)
384 nk_input_key(ctx, NK_KEY_TEXT_LINE_START, down && state[SDL_SCANCODE_LCTRL]);
385 else if (sym == SDLK_e)
386 nk_input_key(ctx, NK_KEY_TEXT_LINE_END, down && state[SDL_SCANCODE_LCTRL]);
387 else if (sym == SDLK_UP)
388 nk_input_key(ctx, NK_KEY_UP, down);
389 else if (sym == SDLK_DOWN)
390 nk_input_key(ctx, NK_KEY_DOWN, down);
391 else if (sym == SDLK_LEFT) {
392 if (state[SDL_SCANCODE_LCTRL])
393 nk_input_key(ctx, NK_KEY_TEXT_WORD_LEFT, down);
394 else nk_input_key(ctx, NK_KEY_LEFT, down);
395 } else if (sym == SDLK_RIGHT) {
396 if (state[SDL_SCANCODE_LCTRL])
397 nk_input_key(ctx, NK_KEY_TEXT_WORD_RIGHT, down);
398 else nk_input_key(ctx, NK_KEY_RIGHT, down);
399 } else return 0;
400 return 1;
401 } else if (evt->type == SDL_MOUSEBUTTONDOWN || evt->type == SDL_MOUSEBUTTONUP) {
402 /* mouse button */
403 int down = evt->type == SDL_MOUSEBUTTONDOWN;
404 const int x = evt->button.x, y = evt->button.y;
405 if (evt->button.button == SDL_BUTTON_LEFT) {
406 if (evt->button.clicks > 1)
407 nk_input_button(ctx, NK_BUTTON_DOUBLE, x, y, down);
408 nk_input_button(ctx, NK_BUTTON_LEFT, x, y, down);
409 } else if (evt->button.button == SDL_BUTTON_MIDDLE)
410 nk_input_button(ctx, NK_BUTTON_MIDDLE, x, y, down);
411 else if (evt->button.button == SDL_BUTTON_RIGHT)
412 nk_input_button(ctx, NK_BUTTON_RIGHT, x, y, down);
413 return 1;
414 } else if (evt->type == SDL_MOUSEMOTION) {
415 /* mouse motion */
416 if (ctx->input.mouse.grabbed) {
417 int x = (int)ctx->input.mouse.prev.x, y = (int)ctx->input.mouse.prev.y;
418 nk_input_motion(ctx, x + evt->motion.xrel, y + evt->motion.yrel);
419 } else nk_input_motion(ctx, evt->motion.x, evt->motion.y);
420 return 1;
421 } else if (evt->type == SDL_TEXTINPUT) {
422 /* text input */
423 nk_glyph glyph;
424 memcpy(glyph, evt->text.text, NK_UTF_SIZE);
425 nk_input_glyph(ctx, glyph);
426 return 1;
427 } else if (evt->type == SDL_MOUSEWHEEL) {
428 /* mouse wheel */
429 nk_input_scroll(ctx,nk_vec2((float)evt->wheel.x,(float)evt->wheel.y));
430 return 1;
431 }
432 return 0;
433 }
434
435 NK_API
nk_sdl_shutdown(void)436 void nk_sdl_shutdown(void)
437 {
438 nk_font_atlas_clear(&sdl.atlas);
439 nk_free(&sdl.ctx);
440 nk_sdl_device_destroy();
441 memset(&sdl, 0, sizeof(sdl));
442 }
443
444 #endif
445