1 /*
2  * Nuklear - 1.32.0 - public domain
3  * no warrenty implied; use at your own risk.
4  * authored from 2015-2016 by Micha Mettke
5  */
6 /*
7  * ==============================================================
8  *
9  *                              API
10  *
11  * ===============================================================
12  */
13 #ifndef NK_SFML_GL3_H_
14 #define NK_SFML_GL3_H_
15 
16 /* Feel free to edit here and include your own extension wrangler */
17 #include <glad/glad.h>
18 /* I use GLAD but you can use GLEW or what you like */
19 
20 #include <SFML/Window.hpp>
21 
22 NK_API struct nk_context*   nk_sfml_init(sf::Window* window);
23 NK_API void                 nk_sfml_font_stash_begin(struct nk_font_atlas** atlas);
24 NK_API void                 nk_sfml_font_stash_end(void);
25 NK_API int                  nk_sfml_handle_event(sf::Event* event);
26 NK_API void                 nk_sfml_render(enum nk_anti_aliasing, int max_vertex_buffer, int max_element_buffer);
27 NK_API void                 nk_sfml_shutdown(void);
28 
29 NK_API void                 nk_sfml_device_create(void);
30 NK_API void                 nk_sfml_device_destroy(void);
31 
32 #endif
33 /*
34  * ==============================================================
35  *
36  *                          IMPLEMENTATION
37  *
38  * ===============================================================
39  */
40  #ifdef NK_SFML_GL3_IMPLEMENTATION
41 
42 #include <string>
43 
44 struct nk_sfml_device {
45     struct nk_buffer cmds;
46     struct nk_draw_null_texture null;
47     GLuint vbo, vao, 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 };
58 struct nk_sfml_vertex {
59     float position[2];
60     float uv[2];
61     nk_byte col[4];
62 };
63 static struct nk_sfml {
64     sf::Window* window;
65     struct nk_sfml_device ogl;
66     struct nk_context ctx;
67     struct nk_font_atlas atlas;
68 } sfml;
69 
70 #ifdef __APPLE__
71   #define NK_SHADER_VERSION "#version 150\n"
72 #else
73   #define NK_SHADER_VERSION "#version 300 es\n"
74 #endif
75 
76 NK_API void
nk_sfml_device_create(void)77 nk_sfml_device_create(void)
78 {
79     GLint status;
80     static const GLchar* vertex_shader =
81         NK_SHADER_VERSION
82         "uniform mat4 ProjMtx;\n"
83         "in vec2 Position;\n"
84         "in vec2 TexCoord;\n"
85         "in vec4 Color;\n"
86         "out vec2 Frag_UV;\n"
87         "out vec4 Frag_Color;\n"
88         "void main() {\n"
89         "   Frag_UV = TexCoord;\n"
90         "   Frag_Color = Color;\n"
91         "   gl_Position = ProjMtx * vec4(Position.xy, 0, 1);\n"
92         "}\n";
93     static const GLchar *fragment_shader =
94         NK_SHADER_VERSION
95         "precision mediump float;\n"
96         "uniform sampler2D Texture;\n"
97         "in vec2 Frag_UV;\n"
98         "in vec4 Frag_Color;\n"
99         "out vec4 Out_Color;\n"
100         "void main(){\n"
101         "   Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
102         "}\n";
103 
104     struct nk_sfml_device* dev = &sfml.ogl;
105     nk_buffer_init_default(&dev->cmds);
106 
107     dev->prog = glCreateProgram();
108     dev->vert_shdr = glCreateShader(GL_VERTEX_SHADER);
109     dev->frag_shdr = glCreateShader(GL_FRAGMENT_SHADER);
110 
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 
116     glGetShaderiv(dev->vert_shdr, GL_COMPILE_STATUS, &status);
117     assert(status == GL_TRUE);
118 
119     glGetShaderiv(dev->frag_shdr, GL_COMPILE_STATUS, &status);
120     assert(status == GL_TRUE);
121 
122     glAttachShader(dev->prog, dev->vert_shdr);
123     glAttachShader(dev->prog, dev->frag_shdr);
124     glLinkProgram(dev->prog);
125 
126     glGetProgramiv(dev->prog, GL_LINK_STATUS, &status);
127     assert(status == GL_TRUE);
128 
129     dev->uniform_tex = glGetUniformLocation(dev->prog, "Texture");
130     dev->uniform_proj = glGetUniformLocation(dev->prog, "ProjMtx");
131     dev->attrib_pos = glGetAttribLocation(dev->prog, "Position");
132     dev->attrib_uv = glGetAttribLocation(dev->prog, "TexCoord");
133     dev->attrib_col = glGetAttribLocation(dev->prog, "Color");
134     {
135         /* buffer setup */
136         GLsizei vs = sizeof(struct nk_sfml_vertex);
137         size_t vp = offsetof(struct nk_sfml_vertex, position);
138         size_t vt = offsetof(struct nk_sfml_vertex, uv);
139         size_t vc = offsetof(struct nk_sfml_vertex, col);
140 
141         glGenBuffers(1, &dev->vbo);
142         glGenBuffers(1, &dev->ebo);
143         glGenVertexArrays(1, &dev->vao);
144 
145         glBindVertexArray(dev->vao);
146         glBindBuffer(GL_ARRAY_BUFFER, dev->vbo);
147         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, dev->ebo);
148 
149         glEnableVertexAttribArray((GLuint)dev->attrib_pos);
150         glEnableVertexAttribArray((GLuint)dev->attrib_uv);
151         glEnableVertexAttribArray((GLuint)dev->attrib_col);
152 
153         glVertexAttribPointer((GLuint)dev->attrib_pos, 2, GL_FLOAT, GL_FALSE, vs, (void*)vp);
154         glVertexAttribPointer((GLuint)dev->attrib_uv, 2, GL_FLOAT, GL_FALSE, vs, (void*)vt);
155         glVertexAttribPointer((GLuint)dev->attrib_col, 4, GL_UNSIGNED_BYTE, GL_TRUE, vs, (void*)vc);
156     }
157     glBindTexture(GL_TEXTURE_2D, 0);
158     glBindBuffer(GL_ARRAY_BUFFER, 0);
159     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
160     glBindVertexArray(0);
161 }
162 
163 NK_API void
nk_sfml_device_destroy(void)164 nk_sfml_device_destroy(void)
165 {
166     struct nk_sfml_device* dev = &sfml.ogl;
167 
168     glDetachShader(dev->prog, dev->vert_shdr);
169     glDetachShader(dev->prog, dev->frag_shdr);
170     glDeleteShader(dev->vert_shdr);
171     glDeleteShader(dev->vert_shdr);
172     glDeleteProgram(dev->prog);
173     glDeleteTextures(1, &dev->font_tex);
174     glDeleteBuffers(1, &dev->vbo);
175     glDeleteBuffers(1, &dev->ebo);
176     nk_buffer_free(&dev->cmds);
177 }
178 
179 NK_INTERN void
nk_sfml_device_upload_atlas(const void * image,int width,int height)180 nk_sfml_device_upload_atlas(const void* image, int width, int height)
181 {
182     struct nk_sfml_device* dev = &sfml.ogl;
183     glGenTextures(1, &dev->font_tex);
184     glBindTexture(GL_TEXTURE_2D, dev->font_tex);
185     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
186     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
187     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (GLsizei)width, (GLsizei)height, 0,
188                 GL_RGBA, GL_UNSIGNED_BYTE, image);
189 }
190 
191 NK_API void
nk_sfml_render(enum nk_anti_aliasing AA,int max_vertex_buffer,int max_element_buffer)192 nk_sfml_render(enum nk_anti_aliasing AA, int max_vertex_buffer, int max_element_buffer)
193 {
194     /* setup global state */
195     struct nk_sfml_device* dev = &sfml.ogl;
196     int window_width = sfml.window->getSize().x;
197     int window_height = sfml.window->getSize().y;
198     GLfloat ortho[4][4] = {
199         {2.0f, 0.0f, 0.0f, 0.0f},
200         {0.0f,-2.0f, 0.0f, 0.0f},
201         {0.0f, 0.0f,-1.0f, 0.0f},
202         {-1.0f,1.0f, 0.0f, 1.0f},
203     };
204     ortho[0][0] /= (GLfloat)window_width;
205     ortho[1][1] /= (GLfloat)window_height;
206 
207     glViewport(0, 0, window_width, window_height);
208     glEnable(GL_BLEND);
209     glBlendEquation(GL_FUNC_ADD);
210     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
211     glDisable(GL_CULL_FACE);
212     glDisable(GL_DEPTH_TEST);
213     glEnable(GL_SCISSOR_TEST);
214     glActiveTexture(GL_TEXTURE0);
215 
216     /* setup program */
217     glUseProgram(dev->prog);
218     glUniform1i(dev->uniform_tex, 0);
219     glUniformMatrix4fv(dev->uniform_proj, 1, GL_FALSE, &ortho[0][0]);
220     {
221         /* convert from command queue into draw list and draw to screen */
222         const struct nk_draw_command *cmd;
223         void *vertices, *elements;
224         const nk_draw_index *offset = NULL;
225 
226         /* allocate vertex and element buffer */
227         glBindVertexArray(dev->vao);
228         glBindBuffer(GL_ARRAY_BUFFER, dev->vbo);
229         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, dev->ebo);
230 
231         glBufferData(GL_ARRAY_BUFFER, max_vertex_buffer, NULL, GL_STREAM_DRAW);
232         glBufferData(GL_ELEMENT_ARRAY_BUFFER, max_element_buffer, NULL, GL_STREAM_DRAW);
233 
234         /* load vertices/elements directly into vertex/element buffer */
235         vertices = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
236         elements = glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_WRITE_ONLY);
237         {
238             /* fill convert configuration */
239             struct nk_convert_config config;
240             static const struct nk_draw_vertex_layout_element vertex_layout[] =  {
241                 {NK_VERTEX_POSITION, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_sfml_vertex, position)},
242                 {NK_VERTEX_TEXCOORD, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_sfml_vertex, uv)},
243                 {NK_VERTEX_COLOR, NK_FORMAT_R8G8B8A8, NK_OFFSETOF(struct nk_sfml_vertex, col)},
244                 {NK_VERTEX_LAYOUT_END}
245             };
246 
247             NK_MEMSET(&config, 0, sizeof(config));
248             config.vertex_layout = vertex_layout;
249             config.vertex_size = sizeof(struct nk_sfml_vertex);
250             config.vertex_alignment = NK_ALIGNOF(struct nk_sfml_vertex);
251             config.null = dev->null;
252             config.circle_segment_count = 22;
253             config.curve_segment_count = 22;
254             config.arc_segment_count = 22;
255             config.global_alpha = 1.0f;
256             config.shape_AA = AA;
257             config.line_AA = AA;
258 
259             /* setup buffers to load vertices and elements */
260             struct nk_buffer vbuf, ebuf;
261             nk_buffer_init_fixed(&vbuf, vertices, (nk_size)max_vertex_buffer);
262             nk_buffer_init_fixed(&ebuf, elements, (nk_size)max_element_buffer);
263             nk_convert(&sfml.ctx, &dev->cmds, &vbuf, &ebuf, &config);
264         }
265         glUnmapBuffer(GL_ARRAY_BUFFER);
266         glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
267 
268         /* iterate over and execute each draw command */
269         nk_draw_foreach(cmd, &sfml.ctx, &dev->cmds)
270         {
271             if (!cmd->elem_count) continue;
272             glBindTexture(GL_TEXTURE_2D, (GLuint)cmd->texture.id);
273             glScissor(
274                 (GLint)(cmd->clip_rect.x),
275                 (GLint)((window_height - (GLint)(cmd->clip_rect.y + cmd->clip_rect.h))),
276                 (GLint)(cmd->clip_rect.w),
277                 (GLint)(cmd->clip_rect.h));
278             glDrawElements(GL_TRIANGLES, (GLsizei)cmd->elem_count, GL_UNSIGNED_SHORT, offset);
279             offset += cmd->elem_count;
280         }
281         nk_clear(&sfml.ctx);
282     }
283     glUseProgram(0);
284     glBindBuffer(GL_ARRAY_BUFFER, 0);
285     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
286     glBindVertexArray(0);
287     glDisable(GL_BLEND);
288     glDisable(GL_SCISSOR_TEST);
289 }
290 
291 static void
nk_sfml_clipboard_paste(nk_handle usr,struct nk_text_edit * edit)292 nk_sfml_clipboard_paste(nk_handle usr, struct nk_text_edit* edit)
293 {
294 #if 0
295     /* Not Implemented in SFML */
296     (void)usr;
297     sf::Clipboard clipboard(sfml.window);
298     const char* text = clipboard.getText();
299     if(text) nk_textedit_paste(edit, text, nk_strlen(text));
300 #endif
301 }
302 static void
nk_sfml_clipboard_copy(nk_handle usr,const char * text,int len)303 nk_sfml_clipboard_copy(nk_handle usr, const char* text, int len)
304 {
305 #if 0
306     char* str = 0;
307     (void)usr;
308     if(!len) return;
309     str = (char*)malloc((size_t)len+1);
310     if(!str) return;
311     memcpy(str, text, (size_t)len);
312     str[len] = '\0';
313 
314     /* Not Implemented in SFML */
315     sf::Clipboard clipboard(sfml.window);
316     clipboard.setText(str);
317     free(str);
318 #endif
319 }
320 
321 NK_API struct nk_context*
nk_sfml_init(sf::Window * window)322 nk_sfml_init(sf::Window* window)
323 {
324     sfml.window = window;
325     nk_init_default(&sfml.ctx, 0);
326     sfml.ctx.clip.copy = nk_sfml_clipboard_copy;
327     sfml.ctx.clip.paste = nk_sfml_clipboard_paste;
328     sfml.ctx.clip.userdata = nk_handle_ptr(0);
329     nk_sfml_device_create();
330     return &sfml.ctx;
331 }
332 
333 NK_API void
nk_sfml_font_stash_begin(struct nk_font_atlas ** atlas)334 nk_sfml_font_stash_begin(struct nk_font_atlas** atlas)
335 {
336     nk_font_atlas_init_default(&sfml.atlas);
337     nk_font_atlas_begin(&sfml.atlas);
338     *atlas = &sfml.atlas;
339 }
340 
341 NK_API void
nk_sfml_font_stash_end()342 nk_sfml_font_stash_end()
343 {
344     const void* image;
345     int w, h;
346     image = nk_font_atlas_bake(&sfml.atlas, &w, &h, NK_FONT_ATLAS_RGBA32);
347     nk_sfml_device_upload_atlas(image, w, h);
348     nk_font_atlas_end(&sfml.atlas, nk_handle_id((int)sfml.ogl.font_tex), &sfml.ogl.null);
349     if(sfml.atlas.default_font)
350         nk_style_set_font(&sfml.ctx, &sfml.atlas.default_font->handle);
351 }
352 
353 NK_API int
nk_sfml_handle_event(sf::Event * evt)354 nk_sfml_handle_event(sf::Event* evt)
355 {
356     struct nk_context* ctx = &sfml.ctx;
357     /* optional grabbing behavior */
358     if(ctx->input.mouse.grab)
359         ctx->input.mouse.grab = 0;
360     else if(ctx->input.mouse.ungrab) {
361         int x = (int)ctx->input.mouse.prev.x;
362         int y = (int)ctx->input.mouse.prev.y;
363         sf::Mouse::setPosition(sf::Vector2i(x, y), *sfml.window);
364         ctx->input.mouse.ungrab = 0;
365     }
366     if(evt->type == sf::Event::KeyReleased || evt->type == sf::Event::KeyPressed)
367     {
368         int down = evt->type == sf::Event::KeyPressed;
369         sf::Keyboard::Key key = evt->key.code;
370         if(key == sf::Keyboard::RShift || key == sf::Keyboard::LShift)
371             nk_input_key(ctx, NK_KEY_SHIFT, down);
372         else if(key == sf::Keyboard::Delete)
373             nk_input_key(ctx, NK_KEY_DEL, down);
374         else if(key == sf::Keyboard::Return)
375             nk_input_key(ctx, NK_KEY_ENTER, down);
376         else if(key == sf::Keyboard::Tab)
377             nk_input_key(ctx, NK_KEY_TAB, down);
378         else if(key == sf::Keyboard::BackSpace)
379             nk_input_key(ctx, NK_KEY_BACKSPACE, down);
380         else if(key == sf::Keyboard::Home) {
381             nk_input_key(ctx, NK_KEY_TEXT_START, down);
382             nk_input_key(ctx, NK_KEY_SCROLL_START, down);
383         } else if(key == sf::Keyboard::End) {
384             nk_input_key(ctx, NK_KEY_TEXT_END, down);
385             nk_input_key(ctx, NK_KEY_SCROLL_END, down);
386         } else if(key == sf::Keyboard::PageDown)
387             nk_input_key(ctx, NK_KEY_SCROLL_DOWN, down);
388         else if(key == sf::Keyboard::PageUp)
389             nk_input_key(ctx, NK_KEY_SCROLL_DOWN, down);
390         else if(key == sf::Keyboard::Z)
391             nk_input_key(ctx, NK_KEY_TEXT_UNDO, down && sf::Keyboard::isKeyPressed(sf::Keyboard::LControl));
392         else if(key == sf::Keyboard::R)
393             nk_input_key(ctx, NK_KEY_TEXT_REDO, down && sf::Keyboard::isKeyPressed(sf::Keyboard::LControl));
394         else if(key == sf::Keyboard::C)
395             nk_input_key(ctx, NK_KEY_COPY, down && sf::Keyboard::isKeyPressed(sf::Keyboard::LControl));
396         else if(key == sf::Keyboard::V)
397             nk_input_key(ctx, NK_KEY_PASTE, down && sf::Keyboard::isKeyPressed(sf::Keyboard::LControl));
398         else if(key == sf::Keyboard::X)
399             nk_input_key(ctx, NK_KEY_CUT, down && sf::Keyboard::isKeyPressed(sf::Keyboard::LControl));
400         else if(key == sf::Keyboard::B)
401             nk_input_key(ctx, NK_KEY_TEXT_LINE_START, down && sf::Keyboard::isKeyPressed(sf::Keyboard::LControl));
402         else if(key == sf::Keyboard::E)
403             nk_input_key(ctx, NK_KEY_TEXT_LINE_END, down && sf::Keyboard::isKeyPressed(sf::Keyboard::LControl));
404         else if(key == sf::Keyboard::Up)
405             nk_input_key(ctx, NK_KEY_UP, down);
406         else if(key == sf::Keyboard::Down)
407             nk_input_key(ctx, NK_KEY_DOWN, down);
408         else if(key == sf::Keyboard::Left) {
409             if(sf::Keyboard::isKeyPressed(sf::Keyboard::LControl))
410                 nk_input_key(ctx, NK_KEY_TEXT_WORD_LEFT, down);
411             else nk_input_key(ctx, NK_KEY_LEFT, down);
412         } else if(key == sf::Keyboard::Right) {
413             if(sf::Keyboard::isKeyPressed(sf::Keyboard::LControl))
414                 nk_input_key(ctx, NK_KEY_TEXT_WORD_RIGHT, down);
415             else nk_input_key(ctx, NK_KEY_RIGHT, down);
416         } else return 0;
417         return 1;
418     } else if(evt->type == sf::Event::MouseButtonPressed || evt->type == sf::Event::MouseButtonReleased) {
419         int down = evt->type == sf::Event::MouseButtonPressed;
420         const int x = evt->mouseButton.x, y = evt->mouseButton.y;
421         if(evt->mouseButton.button == sf::Mouse::Left)
422             nk_input_button(ctx, NK_BUTTON_LEFT, x, y, down);
423         if(evt->mouseButton.button == sf::Mouse::Middle)
424             nk_input_button(ctx, NK_BUTTON_MIDDLE, x, y, down);
425         if(evt->mouseButton.button == sf::Mouse::Right)
426             nk_input_button(ctx, NK_BUTTON_RIGHT, x, y, down);
427         else return 0;
428         return 1;
429     } else if(evt->type == sf::Event::MouseMoved) {
430         nk_input_motion(ctx, evt->mouseMove.x, evt->mouseMove.y);
431         return 1;
432     } else if(evt->type == sf::Event::TouchBegan || evt->type == sf::Event::TouchEnded) {
433         int down = evt->type == sf::Event::TouchBegan;
434         const int x = evt->touch.x, y = evt->touch.y;
435         nk_input_button(ctx, NK_BUTTON_LEFT, x, y, down);
436         return 1;
437     } else if(evt->type == sf::Event::TouchMoved) {
438         if(ctx->input.mouse.grabbed) {
439             int x = (int)ctx->input.mouse.prev.x;
440             int y = (int)ctx->input.mouse.prev.y;
441             nk_input_motion(ctx, x + evt->touch.x, y + evt->touch.y);
442         } else nk_input_motion(ctx, evt->touch.x, evt->touch.y);
443         return 1;
444     } else if(evt->type == sf::Event::TextEntered) {
445         nk_input_unicode(ctx, evt->text.unicode);
446         return 1;
447     } else if(evt->type == sf::Event::MouseWheelScrolled) {
448         nk_input_scroll(ctx, nk_vec2(0,evt->mouseWheelScroll.delta));
449         return 1;
450     }
451     return 0;
452 }
453 
454 NK_API
nk_sfml_shutdown()455 void nk_sfml_shutdown()
456 {
457     nk_font_atlas_clear(&sfml.atlas);
458     nk_free(&sfml.ctx);
459     nk_sfml_device_destroy();
460     memset(&sfml, 0, sizeof(sfml));
461 }
462 
463 #endif
464