xref: /third_party/glfw/deps/nuklear_glfw_gl2.h (revision b877906b)
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
18enum nk_glfw_init_state{
19    NK_GLFW3_DEFAULT = 0,
20    NK_GLFW3_INSTALL_CALLBACKS
21};
22NK_API struct nk_context*   nk_glfw3_init(GLFWwindow *win, enum nk_glfw_init_state);
23NK_API void                 nk_glfw3_font_stash_begin(struct nk_font_atlas **atlas);
24NK_API void                 nk_glfw3_font_stash_end(void);
25
26NK_API void                 nk_glfw3_new_frame(void);
27NK_API void                 nk_glfw3_render(enum nk_anti_aliasing);
28NK_API void                 nk_glfw3_shutdown(void);
29
30NK_API void                 nk_glfw3_char_callback(GLFWwindow *win, unsigned int codepoint);
31NK_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
54struct nk_glfw_device {
55    struct nk_buffer cmds;
56    struct nk_draw_null_texture null;
57    GLuint font_tex;
58};
59
60struct nk_glfw_vertex {
61    float position[2];
62    float uv[2];
63    nk_byte col[4];
64};
65
66static 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
82NK_INTERN void
83nk_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
94NK_API void
95nk_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
200NK_API void
201nk_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
208NK_API void
209nk_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
216NK_API void
217nk_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
232NK_INTERN void
233nk_glfw3_clipboard_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
240NK_INTERN void
241nk_glfw3_clipboard_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
254NK_API struct nk_context*
255nk_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_clipboard_copy;
265    glfw.ctx.clip.paste = nk_glfw3_clipboard_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
275NK_API void
276nk_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
283NK_API void
284nk_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
294NK_API void
295nk_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
370NK_API
371void 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