imgui_impl_opengl3.cpp 36 KB

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  1. // dear imgui: Renderer Backend for modern OpenGL with shaders / programmatic pipeline
  2. // - Desktop GL: 2.x 3.x 4.x
  3. // - Embedded GL: ES 2.0 (WebGL 1.0), ES 3.0 (WebGL 2.0)
  4. // This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
  5. // Implemented features:
  6. // [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
  7. // [X] Renderer: Multi-viewport support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
  8. // [x] Renderer: Desktop GL only: Support for large meshes (64k+ vertices) with 16-bit indices.
  9. // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
  10. // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
  11. // Read online: https://github.com/ocornut/imgui/tree/master/docs
  12. // CHANGELOG
  13. // (minor and older changes stripped away, please see git history for details)
  14. // 2021-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
  15. // 2021-05-24: OpenGL: Access GL_CLIP_ORIGIN when "GL_ARB_clip_control" extension is detected, inside of just OpenGL 4.5 version.
  16. // 2021-05-19: OpenGL: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
  17. // 2021-04-06: OpenGL: Don't try to read GL_CLIP_ORIGIN unless we're OpenGL 4.5 or greater.
  18. // 2021-02-18: OpenGL: Change blending equation to preserve alpha in output buffer.
  19. // 2021-01-03: OpenGL: Backup, setup and restore GL_STENCIL_TEST state.
  20. // 2020-10-23: OpenGL: Backup, setup and restore GL_PRIMITIVE_RESTART state.
  21. // 2020-10-15: OpenGL: Use glGetString(GL_VERSION) instead of glGetIntegerv(GL_MAJOR_VERSION, ...) when the later returns zero (e.g. Desktop GL 2.x)
  22. // 2020-09-17: OpenGL: Fix to avoid compiling/calling glBindSampler() on ES or pre 3.3 context which have the defines set by a loader.
  23. // 2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
  24. // 2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
  25. // 2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by inverting projection matrix.
  26. // 2020-04-12: OpenGL: Fixed context version check mistakenly testing for 4.0+ instead of 3.2+ to enable ImGuiBackendFlags_RendererHasVtxOffset.
  27. // 2020-03-24: OpenGL: Added support for glbinding 2.x OpenGL loader.
  28. // 2020-01-07: OpenGL: Added support for glbinding 3.x OpenGL loader.
  29. // 2019-10-25: OpenGL: Using a combination of GL define and runtime GL version to decide whether to use glDrawElementsBaseVertex(). Fix building with pre-3.2 GL loaders.
  30. // 2019-09-22: OpenGL: Detect default GL loader using __has_include compiler facility.
  31. // 2019-09-16: OpenGL: Tweak initialization code to allow application calling ImGui_ImplOpenGL3_CreateFontsTexture() before the first NewFrame() call.
  32. // 2019-05-29: OpenGL: Desktop GL only: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
  33. // 2019-04-30: OpenGL: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
  34. // 2019-03-29: OpenGL: Not calling glBindBuffer more than necessary in the render loop.
  35. // 2019-03-15: OpenGL: Added a GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early.
  36. // 2019-03-03: OpenGL: Fix support for ES 2.0 (WebGL 1.0).
  37. // 2019-02-20: OpenGL: Fix for OSX not supporting OpenGL 4.5, we don't try to read GL_CLIP_ORIGIN even if defined by the headers/loader.
  38. // 2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
  39. // 2019-02-01: OpenGL: Using GLSL 410 shaders for any version over 410 (e.g. 430, 450).
  40. // 2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
  41. // 2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT) / GL_CLIP_ORIGIN.
  42. // 2018-08-29: OpenGL: Added support for more OpenGL loaders: glew and glad, with comments indicative that any loader can be used.
  43. // 2018-08-09: OpenGL: Default to OpenGL ES 3 on iOS and Android. GLSL version default to "#version 300 ES".
  44. // 2018-07-30: OpenGL: Support for GLSL 300 ES and 410 core. Fixes for Emscripten compilation.
  45. // 2018-07-10: OpenGL: Support for more GLSL versions (based on the GLSL version string). Added error output when shaders fail to compile/link.
  46. // 2018-06-08: Misc: Extracted imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3 examples.
  47. // 2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
  48. // 2018-05-25: OpenGL: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
  49. // 2018-05-14: OpenGL: Making the call to glBindSampler() optional so 3.2 context won't fail if the function is a NULL pointer.
  50. // 2018-03-06: OpenGL: Added const char* glsl_version parameter to ImGui_ImplOpenGL3_Init() so user can override the GLSL version e.g. "#version 150".
  51. // 2018-02-23: OpenGL: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context.
  52. // 2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplSdlGL3_RenderDrawData() in the .h file so you can call it yourself.
  53. // 2018-01-07: OpenGL: Changed GLSL shader version from 330 to 150.
  54. // 2017-09-01: OpenGL: Save and restore current bound sampler. Save and restore current polygon mode.
  55. // 2017-05-01: OpenGL: Fixed save and restore of current blend func state.
  56. // 2017-05-01: OpenGL: Fixed save and restore of current GL_ACTIVE_TEXTURE.
  57. // 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
  58. // 2016-07-29: OpenGL: Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes it. (#752)
  59. //----------------------------------------
  60. // OpenGL GLSL GLSL
  61. // version version string
  62. //----------------------------------------
  63. // 2.0 110 "#version 110"
  64. // 2.1 120 "#version 120"
  65. // 3.0 130 "#version 130"
  66. // 3.1 140 "#version 140"
  67. // 3.2 150 "#version 150"
  68. // 3.3 330 "#version 330 core"
  69. // 4.0 400 "#version 400 core"
  70. // 4.1 410 "#version 410 core"
  71. // 4.2 420 "#version 410 core"
  72. // 4.3 430 "#version 430 core"
  73. // ES 2.0 100 "#version 100" = WebGL 1.0
  74. // ES 3.0 300 "#version 300 es" = WebGL 2.0
  75. //----------------------------------------
  76. #if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
  77. #define _CRT_SECURE_NO_WARNINGS
  78. #endif
  79. #include "imgui.h"
  80. #include "imgui_impl_opengl3.h"
  81. #include <stdio.h>
  82. #if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
  83. #include <stddef.h> // intptr_t
  84. #else
  85. #include <stdint.h> // intptr_t
  86. #endif
  87. // GL includes
  88. #if defined(IMGUI_IMPL_OPENGL_ES2)
  89. #include <GLES2/gl2.h>
  90. #elif defined(IMGUI_IMPL_OPENGL_ES3)
  91. #if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
  92. #include <OpenGLES/ES3/gl.h> // Use GL ES 3
  93. #else
  94. #include <GLES3/gl3.h> // Use GL ES 3
  95. #endif
  96. #else
  97. // About Desktop OpenGL function loaders:
  98. // Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
  99. // Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad).
  100. // You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.
  101. #if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
  102. #include <GL/gl3w.h> // Needs to be initialized with gl3wInit() in user's code
  103. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
  104. #include <GL/glew.h> // Needs to be initialized with glewInit() in user's code.
  105. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
  106. #include <glad/glad.h> // Needs to be initialized with gladLoadGL() in user's code.
  107. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
  108. #include <glad/gl.h> // Needs to be initialized with gladLoadGL(...) or gladLoaderLoadGL() in user's code.
  109. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
  110. #ifndef GLFW_INCLUDE_NONE
  111. #define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
  112. #endif
  113. #include <glbinding/Binding.h> // Needs to be initialized with glbinding::Binding::initialize() in user's code.
  114. #include <glbinding/gl/gl.h>
  115. using namespace gl;
  116. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
  117. #ifndef GLFW_INCLUDE_NONE
  118. #define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
  119. #endif
  120. #include <glbinding/glbinding.h>// Needs to be initialized with glbinding::initialize() in user's code.
  121. #include <glbinding/gl/gl.h>
  122. using namespace gl;
  123. #else
  124. #include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
  125. #endif
  126. #endif
  127. // Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't have.
  128. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_2)
  129. #define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
  130. #endif
  131. // Desktop GL 3.3+ has glBindSampler()
  132. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_3)
  133. #define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
  134. #endif
  135. // Desktop GL 3.1+ has GL_PRIMITIVE_RESTART state
  136. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_1)
  137. #define IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
  138. #endif
  139. // Desktop GL use extension detection
  140. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3)
  141. #define IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
  142. #endif
  143. // OpenGL Data
  144. static GLuint g_GlVersion = 0; // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
  145. static char g_GlslVersionString[32] = ""; // Specified by user or detected based on compile time GL settings.
  146. static GLuint g_FontTexture = 0;
  147. static GLuint g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
  148. static GLint g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; // Uniforms location
  149. static GLuint g_AttribLocationVtxPos = 0, g_AttribLocationVtxUV = 0, g_AttribLocationVtxColor = 0; // Vertex attributes location
  150. static unsigned int g_VboHandle = 0, g_ElementsHandle = 0;
  151. static bool g_HasClipOrigin = false;
  152. // Forward Declarations
  153. static void ImGui_ImplOpenGL3_InitPlatformInterface();
  154. static void ImGui_ImplOpenGL3_ShutdownPlatformInterface();
  155. // Functions
  156. bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
  157. {
  158. // Query for GL version (e.g. 320 for GL 3.2)
  159. #if !defined(IMGUI_IMPL_OPENGL_ES2)
  160. GLint major = 0;
  161. GLint minor = 0;
  162. glGetIntegerv(GL_MAJOR_VERSION, &major);
  163. glGetIntegerv(GL_MINOR_VERSION, &minor);
  164. if (major == 0 && minor == 0)
  165. {
  166. // Query GL_VERSION in desktop GL 2.x, the string will start with "<major>.<minor>"
  167. const char* gl_version = (const char*)glGetString(GL_VERSION);
  168. sscanf(gl_version, "%d.%d", &major, &minor);
  169. }
  170. g_GlVersion = (GLuint)(major * 100 + minor * 10);
  171. #else
  172. g_GlVersion = 200; // GLES 2
  173. #endif
  174. // Setup backend capabilities flags
  175. ImGuiIO& io = ImGui::GetIO();
  176. io.BackendRendererName = "imgui_impl_opengl3";
  177. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
  178. if (g_GlVersion >= 320)
  179. io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
  180. #endif
  181. io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports; // We can create multi-viewports on the Renderer side (optional)
  182. // Store GLSL version string so we can refer to it later in case we recreate shaders.
  183. // Note: GLSL version is NOT the same as GL version. Leave this to NULL if unsure.
  184. #if defined(IMGUI_IMPL_OPENGL_ES2)
  185. if (glsl_version == NULL)
  186. glsl_version = "#version 100";
  187. #elif defined(IMGUI_IMPL_OPENGL_ES3)
  188. if (glsl_version == NULL)
  189. glsl_version = "#version 300 es";
  190. #elif defined(__APPLE__)
  191. if (glsl_version == NULL)
  192. glsl_version = "#version 150";
  193. #else
  194. if (glsl_version == NULL)
  195. glsl_version = "#version 130";
  196. #endif
  197. IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(g_GlslVersionString));
  198. strcpy(g_GlslVersionString, glsl_version);
  199. strcat(g_GlslVersionString, "\n");
  200. // Debugging construct to make it easily visible in the IDE and debugger which GL loader has been selected.
  201. // The code actually never uses the 'gl_loader' variable! It is only here so you can read it!
  202. // If auto-detection fails or doesn't select the same GL loader file as used by your application,
  203. // you are likely to get a crash below.
  204. // You can explicitly select a loader by using '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
  205. const char* gl_loader = "Unknown";
  206. IM_UNUSED(gl_loader);
  207. #if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
  208. gl_loader = "GL3W";
  209. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
  210. gl_loader = "GLEW";
  211. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
  212. gl_loader = "GLAD";
  213. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
  214. gl_loader = "GLAD2";
  215. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
  216. gl_loader = "glbinding2";
  217. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
  218. gl_loader = "glbinding3";
  219. #elif defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
  220. gl_loader = "custom";
  221. #else
  222. gl_loader = "none";
  223. #endif
  224. // Make an arbitrary GL call (we don't actually need the result)
  225. // IF YOU GET A CRASH HERE: it probably means that you haven't initialized the OpenGL function loader used by this code.
  226. // Desktop OpenGL 3/4 need a function loader. See the IMGUI_IMPL_OPENGL_LOADER_xxx explanation above.
  227. GLint current_texture;
  228. glGetIntegerv(GL_TEXTURE_BINDING_2D, &current_texture);
  229. // Detect extensions we support
  230. g_HasClipOrigin = (g_GlVersion >= 450);
  231. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
  232. GLint num_extensions = 0;
  233. glGetIntegerv(GL_NUM_EXTENSIONS, &num_extensions);
  234. for (GLint i = 0; i < num_extensions; i++)
  235. {
  236. const char* extension = (const char*)glGetStringi(GL_EXTENSIONS, i);
  237. if (strcmp(extension, "GL_ARB_clip_control") == 0)
  238. g_HasClipOrigin = true;
  239. }
  240. #endif
  241. if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
  242. ImGui_ImplOpenGL3_InitPlatformInterface();
  243. return true;
  244. }
  245. void ImGui_ImplOpenGL3_Shutdown()
  246. {
  247. ImGui_ImplOpenGL3_ShutdownPlatformInterface();
  248. ImGui_ImplOpenGL3_DestroyDeviceObjects();
  249. }
  250. void ImGui_ImplOpenGL3_NewFrame()
  251. {
  252. if (!g_ShaderHandle)
  253. ImGui_ImplOpenGL3_CreateDeviceObjects();
  254. }
  255. static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height, GLuint vertex_array_object)
  256. {
  257. // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
  258. glEnable(GL_BLEND);
  259. glBlendEquation(GL_FUNC_ADD);
  260. glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
  261. glDisable(GL_CULL_FACE);
  262. glDisable(GL_DEPTH_TEST);
  263. glDisable(GL_STENCIL_TEST);
  264. glEnable(GL_SCISSOR_TEST);
  265. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
  266. if (g_GlVersion >= 310)
  267. glDisable(GL_PRIMITIVE_RESTART);
  268. #endif
  269. #ifdef GL_POLYGON_MODE
  270. glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
  271. #endif
  272. // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT)
  273. #if defined(GL_CLIP_ORIGIN)
  274. bool clip_origin_lower_left = true;
  275. if (g_HasClipOrigin)
  276. {
  277. GLenum current_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)&current_clip_origin);
  278. if (current_clip_origin == GL_UPPER_LEFT)
  279. clip_origin_lower_left = false;
  280. }
  281. #endif
  282. // Setup viewport, orthographic projection matrix
  283. // 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.
  284. glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height);
  285. float L = draw_data->DisplayPos.x;
  286. float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
  287. float T = draw_data->DisplayPos.y;
  288. float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
  289. #if defined(GL_CLIP_ORIGIN)
  290. if (!clip_origin_lower_left) { float tmp = T; T = B; B = tmp; } // Swap top and bottom if origin is upper left
  291. #endif
  292. const float ortho_projection[4][4] =
  293. {
  294. { 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
  295. { 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
  296. { 0.0f, 0.0f, -1.0f, 0.0f },
  297. { (R+L)/(L-R), (T+B)/(B-T), 0.0f, 1.0f },
  298. };
  299. glUseProgram(g_ShaderHandle);
  300. glUniform1i(g_AttribLocationTex, 0);
  301. glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
  302. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
  303. if (g_GlVersion >= 330)
  304. glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
  305. #endif
  306. (void)vertex_array_object;
  307. #ifndef IMGUI_IMPL_OPENGL_ES2
  308. glBindVertexArray(vertex_array_object);
  309. #endif
  310. // Bind vertex/index buffers and setup attributes for ImDrawVert
  311. glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
  312. glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle);
  313. glEnableVertexAttribArray(g_AttribLocationVtxPos);
  314. glEnableVertexAttribArray(g_AttribLocationVtxUV);
  315. glEnableVertexAttribArray(g_AttribLocationVtxColor);
  316. glVertexAttribPointer(g_AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos));
  317. glVertexAttribPointer(g_AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
  318. glVertexAttribPointer(g_AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
  319. }
  320. // OpenGL3 Render function.
  321. // Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly.
  322. // This is in order to be able to run within an OpenGL engine that doesn't do so.
  323. void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
  324. {
  325. // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
  326. int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
  327. int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
  328. if (fb_width <= 0 || fb_height <= 0)
  329. return;
  330. // Backup GL state
  331. GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
  332. glActiveTexture(GL_TEXTURE0);
  333. GLuint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&last_program);
  334. GLuint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint*)&last_texture);
  335. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
  336. GLuint last_sampler; if (g_GlVersion >= 330) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
  337. #endif
  338. GLuint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint*)&last_array_buffer);
  339. #ifndef IMGUI_IMPL_OPENGL_ES2
  340. GLuint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, (GLint*)&last_vertex_array_object);
  341. #endif
  342. #ifdef GL_POLYGON_MODE
  343. GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
  344. #endif
  345. GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
  346. GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
  347. GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb);
  348. GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb);
  349. GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha);
  350. GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha);
  351. GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb);
  352. GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha);
  353. GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
  354. GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
  355. GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
  356. GLboolean last_enable_stencil_test = glIsEnabled(GL_STENCIL_TEST);
  357. GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
  358. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
  359. GLboolean last_enable_primitive_restart = (g_GlVersion >= 310) ? glIsEnabled(GL_PRIMITIVE_RESTART) : GL_FALSE;
  360. #endif
  361. // Setup desired GL state
  362. // Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
  363. // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
  364. GLuint vertex_array_object = 0;
  365. #ifndef IMGUI_IMPL_OPENGL_ES2
  366. glGenVertexArrays(1, &vertex_array_object);
  367. #endif
  368. ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
  369. // Will project scissor/clipping rectangles into framebuffer space
  370. ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
  371. ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
  372. // Render command lists
  373. for (int n = 0; n < draw_data->CmdListsCount; n++)
  374. {
  375. const ImDrawList* cmd_list = draw_data->CmdLists[n];
  376. // Upload vertex/index buffers
  377. glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW);
  378. glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW);
  379. for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
  380. {
  381. const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
  382. if (pcmd->UserCallback != NULL)
  383. {
  384. // User callback, registered via ImDrawList::AddCallback()
  385. // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
  386. if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
  387. ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
  388. else
  389. pcmd->UserCallback(cmd_list, pcmd);
  390. }
  391. else
  392. {
  393. // Project scissor/clipping rectangles into framebuffer space
  394. ImVec4 clip_rect;
  395. clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
  396. clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
  397. clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
  398. clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
  399. if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
  400. {
  401. // Apply scissor/clipping rectangle
  402. glScissor((int)clip_rect.x, (int)(fb_height - clip_rect.w), (int)(clip_rect.z - clip_rect.x), (int)(clip_rect.w - clip_rect.y));
  403. // Bind texture, Draw
  404. glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID());
  405. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
  406. if (g_GlVersion >= 320)
  407. 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);
  408. else
  409. #endif
  410. glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)));
  411. }
  412. }
  413. }
  414. }
  415. // Destroy the temporary VAO
  416. #ifndef IMGUI_IMPL_OPENGL_ES2
  417. glDeleteVertexArrays(1, &vertex_array_object);
  418. #endif
  419. // Restore modified GL state
  420. glUseProgram(last_program);
  421. glBindTexture(GL_TEXTURE_2D, last_texture);
  422. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
  423. if (g_GlVersion >= 330)
  424. glBindSampler(0, last_sampler);
  425. #endif
  426. glActiveTexture(last_active_texture);
  427. #ifndef IMGUI_IMPL_OPENGL_ES2
  428. glBindVertexArray(last_vertex_array_object);
  429. #endif
  430. glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
  431. glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
  432. glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
  433. if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
  434. if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
  435. if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
  436. if (last_enable_stencil_test) glEnable(GL_STENCIL_TEST); else glDisable(GL_STENCIL_TEST);
  437. if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
  438. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
  439. if (g_GlVersion >= 310) { if (last_enable_primitive_restart) glEnable(GL_PRIMITIVE_RESTART); else glDisable(GL_PRIMITIVE_RESTART); }
  440. #endif
  441. #ifdef GL_POLYGON_MODE
  442. glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
  443. #endif
  444. glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
  445. glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
  446. }
  447. bool ImGui_ImplOpenGL3_CreateFontsTexture()
  448. {
  449. // Build texture atlas
  450. ImGuiIO& io = ImGui::GetIO();
  451. unsigned char* pixels;
  452. int width, height;
  453. 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.
  454. // Upload texture to graphics system
  455. GLint last_texture;
  456. glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
  457. glGenTextures(1, &g_FontTexture);
  458. glBindTexture(GL_TEXTURE_2D, g_FontTexture);
  459. glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  460. glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  461. #ifdef GL_UNPACK_ROW_LENGTH
  462. glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
  463. #endif
  464. glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
  465. // Store our identifier
  466. io.Fonts->SetTexID((ImTextureID)(intptr_t)g_FontTexture);
  467. // Restore state
  468. glBindTexture(GL_TEXTURE_2D, last_texture);
  469. return true;
  470. }
  471. void ImGui_ImplOpenGL3_DestroyFontsTexture()
  472. {
  473. if (g_FontTexture)
  474. {
  475. ImGuiIO& io = ImGui::GetIO();
  476. glDeleteTextures(1, &g_FontTexture);
  477. io.Fonts->SetTexID(0);
  478. g_FontTexture = 0;
  479. }
  480. }
  481. // If you get an error please report on github. You may try different GL context version or GLSL version. See GL<>GLSL version table at the top of this file.
  482. static bool CheckShader(GLuint handle, const char* desc)
  483. {
  484. GLint status = 0, log_length = 0;
  485. glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
  486. glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
  487. if ((GLboolean)status == GL_FALSE)
  488. fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile %s!\n", desc);
  489. if (log_length > 1)
  490. {
  491. ImVector<char> buf;
  492. buf.resize((int)(log_length + 1));
  493. glGetShaderInfoLog(handle, log_length, NULL, (GLchar*)buf.begin());
  494. fprintf(stderr, "%s\n", buf.begin());
  495. }
  496. return (GLboolean)status == GL_TRUE;
  497. }
  498. // If you get an error please report on GitHub. You may try different GL context version or GLSL version.
  499. static bool CheckProgram(GLuint handle, const char* desc)
  500. {
  501. GLint status = 0, log_length = 0;
  502. glGetProgramiv(handle, GL_LINK_STATUS, &status);
  503. glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
  504. if ((GLboolean)status == GL_FALSE)
  505. fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! (with GLSL '%s')\n", desc, g_GlslVersionString);
  506. if (log_length > 1)
  507. {
  508. ImVector<char> buf;
  509. buf.resize((int)(log_length + 1));
  510. glGetProgramInfoLog(handle, log_length, NULL, (GLchar*)buf.begin());
  511. fprintf(stderr, "%s\n", buf.begin());
  512. }
  513. return (GLboolean)status == GL_TRUE;
  514. }
  515. bool ImGui_ImplOpenGL3_CreateDeviceObjects()
  516. {
  517. // Backup GL state
  518. GLint last_texture, last_array_buffer;
  519. glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
  520. glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
  521. #ifndef IMGUI_IMPL_OPENGL_ES2
  522. GLint last_vertex_array;
  523. glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
  524. #endif
  525. // Parse GLSL version string
  526. int glsl_version = 130;
  527. sscanf(g_GlslVersionString, "#version %d", &glsl_version);
  528. const GLchar* vertex_shader_glsl_120 =
  529. "uniform mat4 ProjMtx;\n"
  530. "attribute vec2 Position;\n"
  531. "attribute vec2 UV;\n"
  532. "attribute vec4 Color;\n"
  533. "varying vec2 Frag_UV;\n"
  534. "varying vec4 Frag_Color;\n"
  535. "void main()\n"
  536. "{\n"
  537. " Frag_UV = UV;\n"
  538. " Frag_Color = Color;\n"
  539. " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
  540. "}\n";
  541. const GLchar* vertex_shader_glsl_130 =
  542. "uniform mat4 ProjMtx;\n"
  543. "in vec2 Position;\n"
  544. "in vec2 UV;\n"
  545. "in vec4 Color;\n"
  546. "out vec2 Frag_UV;\n"
  547. "out vec4 Frag_Color;\n"
  548. "void main()\n"
  549. "{\n"
  550. " Frag_UV = UV;\n"
  551. " Frag_Color = Color;\n"
  552. " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
  553. "}\n";
  554. const GLchar* vertex_shader_glsl_300_es =
  555. "precision mediump float;\n"
  556. "layout (location = 0) in vec2 Position;\n"
  557. "layout (location = 1) in vec2 UV;\n"
  558. "layout (location = 2) in vec4 Color;\n"
  559. "uniform mat4 ProjMtx;\n"
  560. "out vec2 Frag_UV;\n"
  561. "out vec4 Frag_Color;\n"
  562. "void main()\n"
  563. "{\n"
  564. " Frag_UV = UV;\n"
  565. " Frag_Color = Color;\n"
  566. " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
  567. "}\n";
  568. const GLchar* vertex_shader_glsl_410_core =
  569. "layout (location = 0) in vec2 Position;\n"
  570. "layout (location = 1) in vec2 UV;\n"
  571. "layout (location = 2) in vec4 Color;\n"
  572. "uniform mat4 ProjMtx;\n"
  573. "out vec2 Frag_UV;\n"
  574. "out vec4 Frag_Color;\n"
  575. "void main()\n"
  576. "{\n"
  577. " Frag_UV = UV;\n"
  578. " Frag_Color = Color;\n"
  579. " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
  580. "}\n";
  581. const GLchar* fragment_shader_glsl_120 =
  582. "#ifdef GL_ES\n"
  583. " precision mediump float;\n"
  584. "#endif\n"
  585. "uniform sampler2D Texture;\n"
  586. "varying vec2 Frag_UV;\n"
  587. "varying vec4 Frag_Color;\n"
  588. "void main()\n"
  589. "{\n"
  590. " gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
  591. "}\n";
  592. const GLchar* fragment_shader_glsl_130 =
  593. "uniform sampler2D Texture;\n"
  594. "in vec2 Frag_UV;\n"
  595. "in vec4 Frag_Color;\n"
  596. "out vec4 Out_Color;\n"
  597. "void main()\n"
  598. "{\n"
  599. " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
  600. "}\n";
  601. const GLchar* fragment_shader_glsl_300_es =
  602. "precision mediump float;\n"
  603. "uniform sampler2D Texture;\n"
  604. "in vec2 Frag_UV;\n"
  605. "in vec4 Frag_Color;\n"
  606. "layout (location = 0) out vec4 Out_Color;\n"
  607. "void main()\n"
  608. "{\n"
  609. " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
  610. "}\n";
  611. const GLchar* fragment_shader_glsl_410_core =
  612. "in vec2 Frag_UV;\n"
  613. "in vec4 Frag_Color;\n"
  614. "uniform sampler2D Texture;\n"
  615. "layout (location = 0) out vec4 Out_Color;\n"
  616. "void main()\n"
  617. "{\n"
  618. " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
  619. "}\n";
  620. // Select shaders matching our GLSL versions
  621. const GLchar* vertex_shader = NULL;
  622. const GLchar* fragment_shader = NULL;
  623. if (glsl_version < 130)
  624. {
  625. vertex_shader = vertex_shader_glsl_120;
  626. fragment_shader = fragment_shader_glsl_120;
  627. }
  628. else if (glsl_version >= 410)
  629. {
  630. vertex_shader = vertex_shader_glsl_410_core;
  631. fragment_shader = fragment_shader_glsl_410_core;
  632. }
  633. else if (glsl_version == 300)
  634. {
  635. vertex_shader = vertex_shader_glsl_300_es;
  636. fragment_shader = fragment_shader_glsl_300_es;
  637. }
  638. else
  639. {
  640. vertex_shader = vertex_shader_glsl_130;
  641. fragment_shader = fragment_shader_glsl_130;
  642. }
  643. // Create shaders
  644. const GLchar* vertex_shader_with_version[2] = { g_GlslVersionString, vertex_shader };
  645. g_VertHandle = glCreateShader(GL_VERTEX_SHADER);
  646. glShaderSource(g_VertHandle, 2, vertex_shader_with_version, NULL);
  647. glCompileShader(g_VertHandle);
  648. CheckShader(g_VertHandle, "vertex shader");
  649. const GLchar* fragment_shader_with_version[2] = { g_GlslVersionString, fragment_shader };
  650. g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER);
  651. glShaderSource(g_FragHandle, 2, fragment_shader_with_version, NULL);
  652. glCompileShader(g_FragHandle);
  653. CheckShader(g_FragHandle, "fragment shader");
  654. g_ShaderHandle = glCreateProgram();
  655. glAttachShader(g_ShaderHandle, g_VertHandle);
  656. glAttachShader(g_ShaderHandle, g_FragHandle);
  657. glLinkProgram(g_ShaderHandle);
  658. CheckProgram(g_ShaderHandle, "shader program");
  659. g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture");
  660. g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx");
  661. g_AttribLocationVtxPos = (GLuint)glGetAttribLocation(g_ShaderHandle, "Position");
  662. g_AttribLocationVtxUV = (GLuint)glGetAttribLocation(g_ShaderHandle, "UV");
  663. g_AttribLocationVtxColor = (GLuint)glGetAttribLocation(g_ShaderHandle, "Color");
  664. // Create buffers
  665. glGenBuffers(1, &g_VboHandle);
  666. glGenBuffers(1, &g_ElementsHandle);
  667. ImGui_ImplOpenGL3_CreateFontsTexture();
  668. // Restore modified GL state
  669. glBindTexture(GL_TEXTURE_2D, last_texture);
  670. glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
  671. #ifndef IMGUI_IMPL_OPENGL_ES2
  672. glBindVertexArray(last_vertex_array);
  673. #endif
  674. return true;
  675. }
  676. void ImGui_ImplOpenGL3_DestroyDeviceObjects()
  677. {
  678. if (g_VboHandle) { glDeleteBuffers(1, &g_VboHandle); g_VboHandle = 0; }
  679. if (g_ElementsHandle) { glDeleteBuffers(1, &g_ElementsHandle); g_ElementsHandle = 0; }
  680. if (g_ShaderHandle && g_VertHandle) { glDetachShader(g_ShaderHandle, g_VertHandle); }
  681. if (g_ShaderHandle && g_FragHandle) { glDetachShader(g_ShaderHandle, g_FragHandle); }
  682. if (g_VertHandle) { glDeleteShader(g_VertHandle); g_VertHandle = 0; }
  683. if (g_FragHandle) { glDeleteShader(g_FragHandle); g_FragHandle = 0; }
  684. if (g_ShaderHandle) { glDeleteProgram(g_ShaderHandle); g_ShaderHandle = 0; }
  685. ImGui_ImplOpenGL3_DestroyFontsTexture();
  686. }
  687. //--------------------------------------------------------------------------------------------------------
  688. // MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
  689. // This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
  690. // If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
  691. //--------------------------------------------------------------------------------------------------------
  692. static void ImGui_ImplOpenGL3_RenderWindow(ImGuiViewport* viewport, void*)
  693. {
  694. if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
  695. {
  696. ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
  697. glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
  698. glClear(GL_COLOR_BUFFER_BIT);
  699. }
  700. ImGui_ImplOpenGL3_RenderDrawData(viewport->DrawData);
  701. }
  702. static void ImGui_ImplOpenGL3_InitPlatformInterface()
  703. {
  704. ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
  705. platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
  706. }
  707. static void ImGui_ImplOpenGL3_ShutdownPlatformInterface()
  708. {
  709. ImGui::DestroyPlatformWindows();
  710. }