1 module ecs_utils.imgui_bind;
2 
3 import bindbc.sdl;
4 import cimgui.cimgui;
5 
6 version(WebAssembly)
7 {
8     extern(C):
9     bool ImGui_ImplOpenGL3_Init(const char* glsl_version = null);
10     void ImGui_ImplOpenGL3_Shutdown();
11     void ImGui_ImplOpenGL3_NewFrame();
12     void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data);
13 
14     bool ImGui_ImplSDL2_InitForOpenGL(SDL_Window* window, void* sdl_gl_context);
15     bool ImGui_ImplSDL2_InitForVulkan(SDL_Window* window);
16     bool ImGui_ImplSDL2_InitForD3D(SDL_Window* window);
17     void ImGui_ImplSDL2_Shutdown();
18     void ImGui_ImplSDL2_NewFrame(SDL_Window* window);
19     bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event);
20 }
21 else :
22 
23 import bindbc.sdl;
24 
25 version(WebAssembly)import glad.gl.gles2;
26 else version(Android)import glad.gl.gles2;
27 else import glad.gl.gl;
28 
29 import cimgui.cimgui;
30 
31 extern(C):
32 
33 __gshared SDL_Window* g_Window;
34 __gshared ulong g_Time;
35 __gshared bool[3] g_MousePressed;
36 __gshared SDL_Cursor*[ImGuiMouseCursor_COUNT] g_MouseCursors;
37 __gshared char* g_ClipboardTextData;
38 __gshared GLuint g_FontTexture = 0;
39 
40 const (char)* ImGuiImplSDL2GetClipboardText(void*)
41 {
42     if (g_ClipboardTextData)
43         SDL_free(g_ClipboardTextData);
44     g_ClipboardTextData = SDL_GetClipboardText();
45     return g_ClipboardTextData;
46 }
47 
48 void ImGuiImplSDL2SetClipboardText(void*, const char* text)
49 {
50     SDL_SetClipboardText(text);
51 }
52 
53 bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
54 {
55     ImGuiIO* io = igGetIO();
56     switch (event.type)
57     {
58     case SDL_MOUSEWHEEL:
59         {
60             if (event.wheel.x > 0) io.MouseWheelH += 1;
61             if (event.wheel.x < 0) io.MouseWheelH -= 1;
62             if (event.wheel.y > 0) io.MouseWheel += 1;
63             if (event.wheel.y < 0) io.MouseWheel -= 1;
64             return true;
65         }
66     case SDL_MOUSEBUTTONDOWN:
67         {
68             if (event.button.button == SDL_BUTTON_LEFT) g_MousePressed[0] = true;
69             if (event.button.button == SDL_BUTTON_RIGHT) g_MousePressed[1] = true;
70             if (event.button.button == SDL_BUTTON_MIDDLE) g_MousePressed[2] = true;
71             return true;
72         }
73     case SDL_TEXTINPUT:
74         {
75             ImGuiIO_AddInputCharactersUTF8(io,event.text.text.ptr);
76             return true;
77         }
78     case SDL_KEYDOWN:
79     case SDL_KEYUP:
80         {
81             int key = event.key.keysym.scancode;
82             //IM_ASSERT(key >= 0 && key < IM_ARRAYSIZE(io.KeysDown));
83             io.KeysDown[key] = (event.type == SDL_KEYDOWN);
84             io.KeyShift = ((SDL_GetModState() & KMOD_SHIFT) != 0);
85             io.KeyCtrl = ((SDL_GetModState() & KMOD_CTRL) != 0);
86             io.KeyAlt = ((SDL_GetModState() & KMOD_ALT) != 0);
87             io.KeySuper = ((SDL_GetModState() & KMOD_GUI) != 0);
88             return true;
89         }
90     default:break;
91     }
92     return false;
93 }
94 
95 bool ImGuiImplSDL2Init(SDL_Window* window)
96 {
97     g_Window = window;
98 
99     // Setup back-end capabilities flags
100     ImGuiIO* io = igGetIO();
101     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;       // We can honor GetMouseCursor() values (optional)
102     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;        // We can honor io.WantSetMousePos requests (optional, rarely used)
103     io.BackendPlatformName = "imgui_impl_sdl";
104 
105     // Keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array.
106     io.KeyMap[ImGuiKey_Tab] = SDL_SCANCODE_TAB;
107     io.KeyMap[ImGuiKey_LeftArrow] = SDL_SCANCODE_LEFT;
108     io.KeyMap[ImGuiKey_RightArrow] = SDL_SCANCODE_RIGHT;
109     io.KeyMap[ImGuiKey_UpArrow] = SDL_SCANCODE_UP;
110     io.KeyMap[ImGuiKey_DownArrow] = SDL_SCANCODE_DOWN;
111     io.KeyMap[ImGuiKey_PageUp] = SDL_SCANCODE_PAGEUP;
112     io.KeyMap[ImGuiKey_PageDown] = SDL_SCANCODE_PAGEDOWN;
113     io.KeyMap[ImGuiKey_Home] = SDL_SCANCODE_HOME;
114     io.KeyMap[ImGuiKey_End] = SDL_SCANCODE_END;
115     io.KeyMap[ImGuiKey_Insert] = SDL_SCANCODE_INSERT;
116     io.KeyMap[ImGuiKey_Delete] = SDL_SCANCODE_DELETE;
117     io.KeyMap[ImGuiKey_Backspace] = SDL_SCANCODE_BACKSPACE;
118     io.KeyMap[ImGuiKey_Space] = SDL_SCANCODE_SPACE;
119     io.KeyMap[ImGuiKey_Enter] = SDL_SCANCODE_RETURN;
120     io.KeyMap[ImGuiKey_Escape] = SDL_SCANCODE_ESCAPE;
121     io.KeyMap[ImGuiKey_KeyPadEnter] = SDL_SCANCODE_RETURN2;
122     io.KeyMap[ImGuiKey_A] = SDL_SCANCODE_A;
123     io.KeyMap[ImGuiKey_C] = SDL_SCANCODE_C;
124     io.KeyMap[ImGuiKey_V] = SDL_SCANCODE_V;
125     io.KeyMap[ImGuiKey_X] = SDL_SCANCODE_X;
126     io.KeyMap[ImGuiKey_Y] = SDL_SCANCODE_Y;
127     io.KeyMap[ImGuiKey_Z] = SDL_SCANCODE_Z;
128 
129     io.SetClipboardTextFn = &ImGuiImplSDL2SetClipboardText;
130     io.GetClipboardTextFn = &ImGuiImplSDL2GetClipboardText;
131     io.ClipboardUserData = null;
132 
133     g_MouseCursors[ImGuiMouseCursor_Arrow] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_ARROW);
134     g_MouseCursors[ImGuiMouseCursor_TextInput] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_IBEAM);
135     g_MouseCursors[ImGuiMouseCursor_ResizeAll] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZEALL);
136     g_MouseCursors[ImGuiMouseCursor_ResizeNS] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZENS);
137     g_MouseCursors[ImGuiMouseCursor_ResizeEW] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZEWE);
138     g_MouseCursors[ImGuiMouseCursor_ResizeNESW] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZENESW);
139     g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZENWSE);
140     g_MouseCursors[ImGuiMouseCursor_Hand] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_HAND);
141 
142     //#ifdef _WIN32
143     version(WebAssembly)
144     {
145 
146     }
147     else version(Windows)
148     {
149         SDL_SysWMinfo wmInfo;
150         SDL_VERSION(&wmInfo.version_);
151         SDL_GetWindowWMInfo(window, &wmInfo);
152         io.ImeWindowHandle = wmInfo.info.win.window;
153     }
154     //#else
155         //(void)window;
156     //#endif
157 
158     return true;
159 }
160 
161 bool ImGuiImplSDL2InitForOpenGL(SDL_Window* window, void* sdl_gl_context)
162 {
163     //(void)sdl_gl_context; // Viewport branch will need this.
164     return ImGuiImplSDL2Init(window);
165 }
166 
167 void ImGuiImplSDL2Shutdown()
168 {
169     g_Window = null;
170 
171     // Destroy last known clipboard data
172     if (g_ClipboardTextData)
173         SDL_free(g_ClipboardTextData);
174     g_ClipboardTextData = null;
175 
176     // Destroy SDL mouse cursors
177     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
178         SDL_FreeCursor(g_MouseCursors[cursor_n]);
179     //memset(g_MouseCursors, 0, sizeof(g_MouseCursors));
180 }
181 
182 static void ImGui_ImplSDL2_UpdateMousePosAndButtons()
183 {
184     ImGuiIO* io = igGetIO();
185 
186     // Set OS mouse position if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
187     if (io.WantSetMousePos)
188         SDL_WarpMouseInWindow(g_Window, cast(int)io.MousePos.x, cast(int)io.MousePos.y);
189     else
190         io.MousePos = ImVec2(-float.max, -float.max);
191 
192     int mx, my;
193     Uint32 mouse_buttons = SDL_GetMouseState(&mx, &my);
194     io.MouseDown[0] = g_MousePressed[0] || (mouse_buttons & (SDL_PRESSED<<(SDL_BUTTON_LEFT-1))) != 0;  // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame.
195     io.MouseDown[1] = g_MousePressed[1] || (mouse_buttons & (SDL_PRESSED<<(SDL_BUTTON_RIGHT-1))) != 0;
196     io.MouseDown[2] = g_MousePressed[2] || (mouse_buttons & (SDL_PRESSED<<(SDL_BUTTON_MIDDLE-1))) != 0;
197     g_MousePressed[0] = g_MousePressed[1] = g_MousePressed[2] = false;
198 
199     //#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE && !defined(__EMSCRIPTEN__) && !defined(__ANDROID__) && !(defined(__APPLE__) && TARGET_OS_IOS)
200     /*SDL_Window* focused_window = SDL_GetKeyboardFocus();
201     if (g_Window == focused_window)
202     {
203         // SDL_GetMouseState() gives mouse position seemingly based on the last window entered/focused(?)
204         // The creation of a new windows at runtime and SDL_CaptureMouse both seems to severely mess up with that, so we retrieve that position globally.
205         int wx, wy;
206         SDL_GetWindowPosition(focused_window, &wx, &wy);
207         SDL_GetGlobalMouseState(&mx, &my);
208         mx -= wx;
209         my -= wy;
210         io.MousePos = ImVec2((float)mx, (float)my);
211     }
212 
213     // SDL_CaptureMouse() let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't e.g. trigger the OS window resize cursor.
214     // The function is only supported from SDL 2.0.4 (released Jan 2016)
215     bool any_mouse_button_down = ImGui.IsAnyMouseDown();
216     SDL_CaptureMouse(any_mouse_button_down ? SDL_TRUE : SDL_FALSE);
217 //#else*/
218     if (SDL_GetWindowFlags(g_Window) & SDL_WINDOW_INPUT_FOCUS)
219         io.MousePos = ImVec2(cast(float)mx, cast(float)my);
220 //#endif
221 }
222 
223 static void ImGui_ImplSDL2_UpdateMouseCursor()
224 {
225     ImGuiIO* io = igGetIO();
226     if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
227         return;
228 
229     ImGuiMouseCursor imgui_cursor = igGetMouseCursor();
230     if (io.MouseDrawCursor || imgui_cursor == ImGuiMouseCursor_None)
231     {
232         // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
233         SDL_ShowCursor(SDL_FALSE);
234     }
235     else
236     {
237         // Show OS mouse cursor
238         SDL_SetCursor(g_MouseCursors[imgui_cursor] ? g_MouseCursors[imgui_cursor] : g_MouseCursors[ImGuiMouseCursor_Arrow]);
239         SDL_ShowCursor(SDL_TRUE);
240     }
241 }
242 
243 static void ImGui_ImplSDL2_UpdateGamepads()
244 {
245     ImGuiIO* io = igGetIO();
246     //memset(io.NavInputs, 0, sizeof(io.NavInputs));
247     if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0)
248         return;
249 
250     // Get gamepad
251     SDL_GameController* game_controller = SDL_GameControllerOpen(0);
252     if (!game_controller)
253     {
254         io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
255         return;
256     }
257 
258     // Update gamepad inputs
259     /*#define MAP_BUTTON(NAV_NO, BUTTON_NO)       { io.NavInputs[NAV_NO] = (SDL_GameControllerGetButton(game_controller, BUTTON_NO) != 0) ? 1.0f : 0.0f; }
260     #define MAP_ANALOG(NAV_NO, AXIS_NO, V0, V1) { float vn = (float)(SDL_GameControllerGetAxis(game_controller, AXIS_NO) - V0) / (float)(V1 - V0); if (vn > 1.0f) vn = 1.0f; if (vn > 0.0f && io.NavInputs[NAV_NO] < vn) io.NavInputs[NAV_NO] = vn; }
261     const int thumb_dead_zone = 8000;           // SDL_gamecontroller.h suggests using this value.
262     MAP_BUTTON(ImGuiNavInput_Activate,      SDL_CONTROLLER_BUTTON_A);               // Cross / A
263     MAP_BUTTON(ImGuiNavInput_Cancel,        SDL_CONTROLLER_BUTTON_B);               // Circle / B
264     MAP_BUTTON(ImGuiNavInput_Menu,          SDL_CONTROLLER_BUTTON_X);               // Square / X
265     MAP_BUTTON(ImGuiNavInput_Input,         SDL_CONTROLLER_BUTTON_Y);               // Triangle / Y
266     MAP_BUTTON(ImGuiNavInput_DpadLeft,      SDL_CONTROLLER_BUTTON_DPAD_LEFT);       // D-Pad Left
267     MAP_BUTTON(ImGuiNavInput_DpadRight,     SDL_CONTROLLER_BUTTON_DPAD_RIGHT);      // D-Pad Right
268     MAP_BUTTON(ImGuiNavInput_DpadUp,        SDL_CONTROLLER_BUTTON_DPAD_UP);         // D-Pad Up
269     MAP_BUTTON(ImGuiNavInput_DpadDown,      SDL_CONTROLLER_BUTTON_DPAD_DOWN);       // D-Pad Down
270     MAP_BUTTON(ImGuiNavInput_FocusPrev,     SDL_CONTROLLER_BUTTON_LEFTSHOULDER);    // L1 / LB
271     MAP_BUTTON(ImGuiNavInput_FocusNext,     SDL_CONTROLLER_BUTTON_RIGHTSHOULDER);   // R1 / RB
272     MAP_BUTTON(ImGuiNavInput_TweakSlow,     SDL_CONTROLLER_BUTTON_LEFTSHOULDER);    // L1 / LB
273     MAP_BUTTON(ImGuiNavInput_TweakFast,     SDL_CONTROLLER_BUTTON_RIGHTSHOULDER);   // R1 / RB
274     MAP_ANALOG(ImGuiNavInput_LStickLeft,    SDL_CONTROLLER_AXIS_LEFTX, -thumb_dead_zone, -32768);
275     MAP_ANALOG(ImGuiNavInput_LStickRight,   SDL_CONTROLLER_AXIS_LEFTX, +thumb_dead_zone, +32767);
276     MAP_ANALOG(ImGuiNavInput_LStickUp,      SDL_CONTROLLER_AXIS_LEFTY, -thumb_dead_zone, -32767);
277     MAP_ANALOG(ImGuiNavInput_LStickDown,    SDL_CONTROLLER_AXIS_LEFTY, +thumb_dead_zone, +32767);
278 
279     io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
280     #undef MAP_BUTTON
281     #undef MAP_ANALOG*/
282 }
283 
284 
285 __gshared private long frequency;
286 
287 void ImGuiImplSDL2NewFrame(SDL_Window* window)
288 {
289     ImGuiIO* io = igGetIO();
290     assert(ImFontAtlas_IsBuilt(io.Fonts), "Font atlas not built! It is generally built by the renderer back-end. Missing call to renderer _NewFrame() function? e.g. ImGui_ImplOpenGL3_NewFrame().");
291 
292     // Setup display size (every frame to accommodate for window resizing)
293     int w, h;
294     int display_w, display_h;
295     SDL_GetWindowSize(window, &w, &h);
296     // SDL_GL_GetDrawableSize(window, &display_w, &display_h); FIXME: you see
297     io.DisplaySize = ImVec2(cast(float)w, cast(float)h);
298     // if (w > 0 && h > 0)
299     //     io.DisplayFramebufferScale = ImVec2(cast(float)display_w / w, cast(float)display_h / h);
300     io.DisplayFramebufferScale = ImVec2(1,1);
301 
302     // Setup time step (we don't use SDL_GetTicks() because it is using millisecond resolution)
303     frequency = SDL_GetPerformanceFrequency();
304     long current_time = SDL_GetPerformanceCounter();
305     io.DeltaTime = g_Time > 0 ? cast(float)(cast(double)(current_time - g_Time) / frequency) : cast(float)(1.0f / 60.0f);
306     g_Time = current_time;
307 
308     ImGui_ImplSDL2_UpdateMousePosAndButtons();
309     ImGui_ImplSDL2_UpdateMouseCursor();
310 
311     // Update game controllers (if enabled and available)
312     ImGui_ImplSDL2_UpdateGamepads();
313 }
314 
315 
316 __gshared GLuint       g_GlVersion = 0;                // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
317 __gshared char[32]         g_GlslVersionString = "";   // Specified by user or detected based on compile time GL settings.
318 //__gshared GLuint       g_FontTexture = 0;
319 __gshared GLuint       g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
320 __gshared int          g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0;                                // Uniforms location
321 __gshared int          g_AttribLocationVtxPos = 0, g_AttribLocationVtxUV = 0, g_AttribLocationVtxColor = 0; // Vertex attributes location
322 __gshared uint g_VboHandle = 0, g_ElementsHandle = 0;
323 
324 bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
325 {
326     // Setup back-end capabilities flags
327     ImGuiIO* io = igGetIO();
328     io.BackendRendererName = "imgui_impl_opengl3";
329 
330 
331     // Store GLSL version string so we can refer to it later in case we recreate shaders.
332     // Note: GLSL version is NOT the same as GL version. Leave this to null if unsure.
333 /*#if defined(IMGUI_IMPL_OPENGL_ES2)
334     if (glsl_version == null)
335         glsl_version = "#version 100";
336 #elif defined(IMGUI_IMPL_OPENGL_ES3)
337     if (glsl_version == null)
338         glsl_version = "#version 300 es";
339 #elif defined(__APPLE__)
340     if (glsl_version == null)
341         glsl_version = "#version 150";
342 #else
343     if (glsl_version == null)
344         glsl_version = "#version 130";
345 #endif
346     IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(g_GlslVersionString));*/
347     //const (char)*glsl_version = "#version 100";
348     import core.stdc.string;
349     strcpy(g_GlslVersionString.ptr, glsl_version);
350     strcat(g_GlslVersionString.ptr, "\n");
351 
352     // Dummy construct to make it easily visible in the IDE and debugger which GL loader has been selected.
353     // The code actually never uses the 'gl_loader' variable! It is only here so you can read it!
354     // If auto-detection fails or doesn't select the same GL loader file as used by your application,
355     // you are likely to get a crash below.
356     // You can explicitly select a loader by using '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
357     /*const char* gl_loader = "Unknown";
358     IM_UNUSED(gl_loader);
359 #if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
360     gl_loader = "GL3W";
361 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
362     gl_loader = "GLEW";
363 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
364     gl_loader = "GLAD";
365 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
366     gl_loader = "glbinding2";
367 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
368     gl_loader = "glbinding3";
369 #elif defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
370     gl_loader = "custom";
371 #else
372     gl_loader = "none";
373 #endif*/
374 
375     // Make a dummy GL call (we don't actually need the result)
376     // IF YOU GET A CRASH HERE: it probably means that you haven't initialized the OpenGL function loader used by this code.
377     // Desktop OpenGL 3/4 need a function loader. See the IMGUI_IMPL_OPENGL_LOADER_xxx explanation above.
378     /*GLint current_texture;
379     glGetIntegerv(GL_TEXTURE_BINDING_2D, &current_texture);*/
380 
381     return true;
382 }
383 
384 static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height, GLuint vertex_array_object)
385 {
386     // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
387     glEnable(GL_BLEND);
388     glBlendEquation(GL_FUNC_ADD);
389     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
390     glDisable(GL_CULL_FACE);
391     glDisable(GL_DEPTH_TEST);
392     glEnable(GL_SCISSOR_TEST);
393 // #ifdef GL_POLYGON_MODE
394 //     glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
395 // #endif
396 
397     // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT)
398     bool clip_origin_lower_left = true;
399 // #if defined(GL_CLIP_ORIGIN) && !defined(__APPLE__)
400 //     GLenum current_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)&current_clip_origin);
401 //     if (current_clip_origin == GL_UPPER_LEFT)
402 //         clip_origin_lower_left = false;
403 // #endif
404 
405     // Setup viewport, orthographic projection matrix
406     // Our visible imgui space lies from draw_data.DisplayPos (top left) to draw_data.DisplayPos+data_data.DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
407     glViewport(0, 0, cast(GLsizei)fb_width, cast(GLsizei)fb_height);
408     float L = draw_data.DisplayPos.x;
409     float R = draw_data.DisplayPos.x + draw_data.DisplaySize.x;
410     float T = draw_data.DisplayPos.y;
411     float B = draw_data.DisplayPos.y + draw_data.DisplaySize.y;
412     if (!clip_origin_lower_left) { float tmp = T; T = B; B = tmp; } // Swap top and bottom if origin is upper left
413     const float[4][4] ortho_projection =
414     [
415         [ 2.0f/(R-L),   0.0f,         0.0f,   0.0f ],
416         [ 0.0f,         2.0f/(T-B),   0.0f,   0.0f ],
417         [ 0.0f,         0.0f,        -1.0f,   0.0f ],
418         [ (R+L)/(L-R),  (T+B)/(B-T),  0.0f,   1.0f ],
419     ];
420     glUseProgram(g_ShaderHandle);
421     glUniform1i(g_AttribLocationTex, 0);
422     glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
423 // #ifdef GL_SAMPLER_BINDING
424 //     glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
425 // #endif
426 
427 //     (void)vertex_array_object;
428 // #ifndef IMGUI_IMPL_OPENGL_ES2
429 //     glBindVertexArray(vertex_array_object);
430 // #endif
431 
432     // Bind vertex/index buffers and setup attributes for ImDrawVert
433     glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
434     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle);
435     glEnableVertexAttribArray(g_AttribLocationVtxPos);
436     glEnableVertexAttribArray(g_AttribLocationVtxUV);
437     glEnableVertexAttribArray(g_AttribLocationVtxColor);
438     glVertexAttribPointer(g_AttribLocationVtxPos,   2, GL_FLOAT,         GL_FALSE, ImDrawVert.sizeof, cast(GLvoid*)ImDrawVert.pos.offsetof);
439     glVertexAttribPointer(g_AttribLocationVtxUV,    2, GL_FLOAT,         GL_FALSE, ImDrawVert.sizeof, cast(GLvoid*)ImDrawVert.uv.offsetof);
440     glVertexAttribPointer(g_AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE,  ImDrawVert.sizeof, cast(GLvoid*)ImDrawVert.col.offsetof);
441 }
442 
443 
444 void    ImGui_ImplOpenGL3_Shutdown()
445 {
446     ImGui_ImplOpenGL3_DestroyDeviceObjects();
447 }
448 
449 void    ImGui_ImplOpenGL3_NewFrame()
450 {
451     if (!g_ShaderHandle)
452         ImGui_ImplOpenGL3_CreateDeviceObjects();
453 }
454 
455 bool    ImGui_ImplOpenGL3_CreateDeviceObjects()
456 {
457     // Backup GL state
458     GLint last_texture, last_array_buffer;
459     glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
460     glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
461 // #ifndef IMGUI_IMPL_OPENGL_ES2
462 //     GLint last_vertex_array;
463 //     glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
464 // #endif
465 
466     // Parse GLSL version string
467     import core.stdc.stdio;
468     int glsl_version = 130;
469     sscanf(g_GlslVersionString.ptr, "#version %d", &glsl_version);
470 
471     const GLchar* vertex_shader_glsl_120 =
472         "uniform mat4 ProjMtx;\n
473         attribute vec2 Position;\n
474         attribute vec2 UV;\n
475         attribute vec4 Color;\n
476         varying vec2 Frag_UV;\n
477         varying vec4 Frag_Color;\n
478         void main()\n
479         {\n
480             Frag_UV = UV;\n
481             Frag_Color = Color;\n
482             gl_Position = ProjMtx * vec4(Position.xy,0,1);\n
483         }\n";
484 
485     const GLchar* vertex_shader_glsl_130 =
486         "uniform mat4 ProjMtx;\n
487         in vec2 Position;\n
488         in vec2 UV;\n
489         in vec4 Color;\n
490         out vec2 Frag_UV;\n
491         out vec4 Frag_Color;\n
492         void main()\n
493         {\n
494             Frag_UV = UV;\n
495             Frag_Color = Color;\n
496             gl_Position = ProjMtx * vec4(Position.xy,0,1);\n
497         }\n";
498 
499     const GLchar* vertex_shader_glsl_300_es =
500         "precision mediump float;\n
501         layout (location = 0) in vec2 Position;\n
502         layout (location = 1) in vec2 UV;\n
503         layout (location = 2) in vec4 Color;\n
504         uniform mat4 ProjMtx;\n
505         out vec2 Frag_UV;\n
506         out vec4 Frag_Color;\n
507         void main()\n
508         {\n
509             Frag_UV = UV;\n
510             Frag_Color = Color;\n
511             gl_Position = ProjMtx * vec4(Position.xy,0,1);\n
512         }\n";
513 
514     const GLchar* vertex_shader_glsl_410_core =
515         "layout (location = 0) in vec2 Position;\n
516         layout (location = 1) in vec2 UV;\n
517         layout (location = 2) in vec4 Color;\n
518         uniform mat4 ProjMtx;\n
519         out vec2 Frag_UV;\n
520         out vec4 Frag_Color;\n
521         void main()\n
522         {\n
523             Frag_UV = UV;\n
524             Frag_Color = Color;\n
525             gl_Position = ProjMtx * vec4(Position.xy,0,1);\n
526         }\n";
527 
528     const GLchar* fragment_shader_glsl_120 =
529         "#ifdef GL_ES\n
530             precision mediump float;\n
531         #endif\n
532         uniform sampler2D Texture;\n
533         varying vec2 Frag_UV;\n
534         varying vec4 Frag_Color;\n
535         void main()\n
536         {\n
537             gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n
538         }\n";
539 
540     const GLchar* fragment_shader_glsl_130 =
541         "uniform sampler2D Texture;\n
542         in vec2 Frag_UV;\n
543         in vec4 Frag_Color;\n
544         out vec4 Out_Color;\n
545         void main()\n
546         {\n
547             Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n
548         }\n";
549 
550     const GLchar* fragment_shader_glsl_300_es =
551         "precision mediump float;\n
552         uniform sampler2D Texture;\n
553         in vec2 Frag_UV;\n
554         in vec4 Frag_Color;\n
555         layout (location = 0) out vec4 Out_Color;\n
556         void main()\n
557         {\n
558             Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n
559         }\n";
560 
561     const GLchar* fragment_shader_glsl_410_core =
562         "in vec2 Frag_UV;\n
563         in vec4 Frag_Color;\n
564         uniform sampler2D Texture;\n
565         layout (location = 0) out vec4 Out_Color;\n
566         void main()\n
567         {\n
568             Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n
569         }\n";
570 
571     // Select shaders matching our GLSL versions
572     const (char)* vertex_shader = null;
573     const (char)* fragment_shader = null;
574     if (glsl_version < 130)
575     {
576         vertex_shader = vertex_shader_glsl_120;
577         fragment_shader = fragment_shader_glsl_120;
578     }
579     else if (glsl_version >= 410)
580     {
581         vertex_shader = vertex_shader_glsl_410_core;
582         fragment_shader = fragment_shader_glsl_410_core;
583     }
584     else if (glsl_version == 300)
585     {
586         vertex_shader = vertex_shader_glsl_300_es;
587         fragment_shader = fragment_shader_glsl_300_es;
588     }
589     else
590     {
591         vertex_shader = vertex_shader_glsl_130;
592         fragment_shader = fragment_shader_glsl_130;
593     }
594 
595     // Create shaders
596     const (char)*[2] vertex_shader_with_version = [ g_GlslVersionString.ptr, vertex_shader ];
597     g_VertHandle = glCreateShader(GL_VERTEX_SHADER);
598     glShaderSource(g_VertHandle, 2, vertex_shader_with_version.ptr, null);
599     glCompileShader(g_VertHandle);
600     CheckShader(g_VertHandle, "vertex shader");
601 
602     const (char)*[2] fragment_shader_with_version = [ g_GlslVersionString.ptr, fragment_shader ];
603     g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER);
604     glShaderSource(g_FragHandle, 2, fragment_shader_with_version.ptr, null);
605     glCompileShader(g_FragHandle);
606     CheckShader(g_FragHandle, "fragment shader");
607 
608     g_ShaderHandle = glCreateProgram();
609     glAttachShader(g_ShaderHandle, g_VertHandle);
610     glAttachShader(g_ShaderHandle, g_FragHandle);
611     glLinkProgram(g_ShaderHandle);
612     CheckProgram(g_ShaderHandle, "shader program");
613 
614     g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture");
615     g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx");
616     g_AttribLocationVtxPos = glGetAttribLocation(g_ShaderHandle, "Position");
617     g_AttribLocationVtxUV = glGetAttribLocation(g_ShaderHandle, "UV");
618     g_AttribLocationVtxColor = glGetAttribLocation(g_ShaderHandle, "Color");
619 
620     // Create buffers
621     glGenBuffers(1, &g_VboHandle);
622     glGenBuffers(1, &g_ElementsHandle);
623 
624     ImGui_ImplOpenGL3_CreateFontsTexture();
625 
626     // Restore modified GL state
627     glBindTexture(GL_TEXTURE_2D, last_texture);
628     glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
629 // #ifndef IMGUI_IMPL_OPENGL_ES2
630 //     glBindVertexArray(last_vertex_array);
631 // #endif
632 
633     return true;
634 }
635 
636 void    ImGui_ImplOpenGL3_DestroyDeviceObjects()
637 {
638     if (g_VboHandle)        { glDeleteBuffers(1, &g_VboHandle); g_VboHandle = 0; }
639     if (g_ElementsHandle)   { glDeleteBuffers(1, &g_ElementsHandle); g_ElementsHandle = 0; }
640     if (g_ShaderHandle && g_VertHandle) { glDetachShader(g_ShaderHandle, g_VertHandle); }
641     if (g_ShaderHandle && g_FragHandle) { glDetachShader(g_ShaderHandle, g_FragHandle); }
642     if (g_VertHandle)       { glDeleteShader(g_VertHandle); g_VertHandle = 0; }
643     if (g_FragHandle)       { glDeleteShader(g_FragHandle); g_FragHandle = 0; }
644     if (g_ShaderHandle)     { glDeleteProgram(g_ShaderHandle); g_ShaderHandle = 0; }
645 
646     ImGui_ImplOpenGL3_DestroyFontsTexture();
647 }
648 
649 static bool CheckShader(GLuint handle, const char* desc)
650 {
651     GLint status = 0, log_length = 0;
652     glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
653     glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
654     /*if (cast(GLboolean)status == GL_FALSE)
655         fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile %s!\n", desc);
656     if (log_length > 1)
657     {
658         ImVector<char> buf;
659         buf.resize(cast(int)(log_length + 1));
660         glGetShaderInfoLog(handle, log_length, null, cast(GLchar*)buf.begin());
661         fprintf(stderr, "%s\n", buf.begin());
662     }*/
663     return cast(GLboolean)status == GL_TRUE;
664 }
665 
666 // If you get an error please report on GitHub. You may try different GL context version or GLSL version.
667 static bool CheckProgram(GLuint handle, const char* desc)
668 {
669     GLint status = 0, log_length = 0;
670     glGetProgramiv(handle, GL_LINK_STATUS, &status);
671     glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
672     /*if (cast(GLboolean)status == GL_FALSE)
673         fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! (with GLSL '%s')\n", desc, g_GlslVersionString);
674     if (log_length > 1)
675     {
676         ImVector<char> buf;
677         buf.resize(cast(int)(log_length + 1));
678         glGetProgramInfoLog(handle, log_length, null, cast(GLchar*)buf.begin());
679         fprintf(stderr, "%s\n", buf.begin());
680     }*/
681     return cast(GLboolean)status == GL_TRUE;
682 }
683 
684 bool ImGui_ImplOpenGL3_CreateFontsTexture()
685 {
686     // Build texture atlas
687     ImGuiIO* io = igGetIO();
688     ubyte* pixels;
689     int width, height, bpp;
690 
691     ImFontAtlas_GetTexDataAsRGBA32(io.Fonts,&pixels, &width, &height, &bpp);
692     //io.Fonts.GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
693     
694     // Upload texture to graphics system
695     GLint last_texture;
696     glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
697     glGenTextures(1, &g_FontTexture);
698     glBindTexture(GL_TEXTURE_2D, g_FontTexture);
699     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
700     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
701 // #ifdef GL_UNPACK_ROW_LENGTH
702 //     glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
703 // #endif
704     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
705 
706     // Store our identifier
707     io.Fonts.TexID = cast(ImTextureID)cast(sizediff_t)g_FontTexture;
708 
709     // Restore state
710     glBindTexture(GL_TEXTURE_2D, last_texture);
711 
712     return true;
713 }
714 
715 void ImGui_ImplOpenGL3_DestroyFontsTexture()
716 {
717     if (g_FontTexture)
718     {
719         ImGuiIO* io = igGetIO();
720         glDeleteTextures(1, &g_FontTexture);
721         io.Fonts.TexID = null;
722         g_FontTexture = 0;
723     }
724 }
725 
726 void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
727 {
728     // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
729     int fb_width = cast(int)(draw_data.DisplaySize.x * draw_data.FramebufferScale.x);
730     int fb_height = cast(int)(draw_data.DisplaySize.y * draw_data.FramebufferScale.y);
731     if (fb_width <= 0 || fb_height <= 0)
732         return;
733 
734     // Backup GL state
735     GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, cast(GLint*)&last_active_texture);
736     glActiveTexture(GL_TEXTURE0);
737     GLint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
738     GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
739 // #ifdef GL_SAMPLER_BINDING
740 //     GLint last_sampler; glGetIntegerv(GL_SAMPLER_BINDING, &last_sampler);
741 // #endif
742     GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
743 // #ifndef IMGUI_IMPL_OPENGL_ES2
744 //     GLint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array_object);
745 // #endif
746 // #ifdef GL_POLYGON_MODE
747 //     GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
748 // #endif
749     GLint[4] last_viewport; glGetIntegerv(GL_VIEWPORT, last_viewport.ptr);
750     GLint[4] last_scissor_box; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box.ptr);
751     GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, cast(GLint*)&last_blend_src_rgb);
752     GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, cast(GLint*)&last_blend_dst_rgb);
753     GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, cast(GLint*)&last_blend_src_alpha);
754     GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, cast(GLint*)&last_blend_dst_alpha);
755     GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, cast(GLint*)&last_blend_equation_rgb);
756     GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, cast(GLint*)&last_blend_equation_alpha);
757     GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
758     GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
759     GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
760     GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
761 
762     // Setup desired GL state
763     // Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
764     // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
765     GLuint vertex_array_object = 0;
766 // #ifndef IMGUI_IMPL_OPENGL_ES2
767 //     glGenVertexArrays(1, &vertex_array_object);
768 // #endif
769     ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
770 
771     // Will project scissor/clipping rectangles into framebuffer space
772     ImVec2 clip_off = draw_data.DisplayPos;         // (0,0) unless using multi-viewports
773     ImVec2 clip_scale = draw_data.FramebufferScale; // (1,1) unless using retina display which are often (2,2)
774 
775     // Render command lists
776     for (int n = 0; n < draw_data.CmdListsCount; n++)
777     {
778         const ImDrawList* cmd_list = draw_data.CmdLists[n];
779 
780         // Upload vertex/index buffers
781         glBufferData(GL_ARRAY_BUFFER, cast(GLsizeiptr)cmd_list.VtxBuffer.Size * ImDrawVert.sizeof, cast(const GLvoid*)cmd_list.VtxBuffer.Data, GL_STREAM_DRAW);
782         glBufferData(GL_ELEMENT_ARRAY_BUFFER, cast(GLsizeiptr)cmd_list.IdxBuffer.Size * ImDrawIdx.sizeof, cast(const GLvoid*)cmd_list.IdxBuffer.Data, GL_STREAM_DRAW);
783 
784         for (int cmd_i = 0; cmd_i < cmd_list.CmdBuffer.Size; cmd_i++)
785         {
786             const ImDrawCmd* pcmd = &cmd_list.CmdBuffer.Data[cmd_i];
787             if (pcmd.UserCallback != null)
788             {
789                 // User callback, registered via ImDrawList::AddCallback()
790                 // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
791                 // if (pcmd.UserCallback == ImDrawCallback_ResetRenderState)
792                 //     ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
793                 // else
794                     pcmd.UserCallback(cmd_list, pcmd);
795             }
796             else
797             {
798                 // Project scissor/clipping rectangles into framebuffer space
799                 ImVec4 clip_rect = ImVec4(0,0,0,0);
800                 clip_rect.x = (pcmd.ClipRect.x - clip_off.x) * clip_scale.x;
801                 clip_rect.y = (pcmd.ClipRect.y - clip_off.y) * clip_scale.y;
802                 clip_rect.z = (pcmd.ClipRect.z - clip_off.x) * clip_scale.x;
803                 clip_rect.w = (pcmd.ClipRect.w - clip_off.y) * clip_scale.y;
804 
805                 if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
806                 {
807                     // Apply scissor/clipping rectangle
808                     glScissor(cast(int)clip_rect.x, cast(int)(fb_height - clip_rect.w), cast(int)(clip_rect.z - clip_rect.x), cast(int)(clip_rect.w - clip_rect.y));
809 
810                     // Bind texture, Draw
811                     glBindTexture(GL_TEXTURE_2D, cast(GLuint)cast(sizediff_t)pcmd.TextureId);
812 // #if IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
813 //                     if (g_GlVersion >= 320)
814 //                         glDrawElementsBaseVertex(GL_TRIANGLES, (GLsizei)pcmd.ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd.IdxOffset * sizeof(ImDrawIdx)), (GLint)pcmd.VtxOffset);
815 //                     else
816 // #endif
817                     glDrawElements(GL_TRIANGLES, cast(GLsizei)pcmd.ElemCount, ImDrawIdx.sizeof == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, cast(void*)cast(sizediff_t)(pcmd.IdxOffset * ImDrawIdx.sizeof));
818                 }
819             }
820         }
821     }
822 
823     // Destroy the temporary VAO
824 // #ifndef IMGUI_IMPL_OPENGL_ES2
825 //     glDeleteVertexArrays(1, &vertex_array_object);
826 // #endif
827 
828     // Restore modified GL state
829     glUseProgram(last_program);
830     glBindTexture(GL_TEXTURE_2D, last_texture);
831 // #ifdef GL_SAMPLER_BINDING
832 //     glBindSampler(0, last_sampler);
833 // #endif
834     glActiveTexture(last_active_texture);
835 // #ifndef IMGUI_IMPL_OPENGL_ES2
836 //     glBindVertexArray(last_vertex_array_object);
837 // #endif
838     glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
839     glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
840     glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
841     if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
842     if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
843     if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
844     if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
845 // #ifdef GL_POLYGON_MODE
846 //     glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
847 // #endif
848     glViewport(last_viewport[0], last_viewport[1], cast(GLsizei)last_viewport[2], cast(GLsizei)last_viewport[3]);
849     glScissor(last_scissor_box[0], last_scissor_box[1], cast(GLsizei)last_scissor_box[2], cast(GLsizei)last_scissor_box[3]);
850 }