imgui_impl_opengl3.cpp 42 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: Desktop GL only: Support for large meshes (64k+ vertices) with 16-bit indices.
  8. // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
  9. // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
  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. // 2022-11-09: OpenGL: Reverted use of glBufferSubData(), too many corruptions issues + old issues seemingly can't be reproed with Intel drivers nowadays (revert 2021-12-15 and 2022-05-23 changes).
  15. // 2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
  16. // 2022-09-27: OpenGL: Added ability to '#define IMGUI_IMPL_OPENGL_DEBUG'.
  17. // 2022-05-23: OpenGL: Reworking 2021-12-15 "Using buffer orphaning" so it only happens on Intel GPU, seems to cause problems otherwise. (#4468, #4825, #4832, #5127).
  18. // 2022-05-13: OpenGL: Fix state corruption on OpenGL ES 2.0 due to not preserving GL_ELEMENT_ARRAY_BUFFER_BINDING and vertex attribute states.
  19. // 2021-12-15: OpenGL: Using buffer orphaning + glBufferSubData(), seems to fix leaks with multi-viewports with some Intel HD drivers.
  20. // 2021-08-23: OpenGL: Fixed ES 3.0 shader ("#version 300 es") use normal precision floats to avoid wobbly rendering at HD resolutions.
  21. // 2021-08-19: OpenGL: Embed and use our own minimal GL loader (imgui_impl_opengl3_loader.h), removing requirement and support for third-party loader.
  22. // 2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
  23. // 2021-06-25: OpenGL: Use OES_vertex_array extension on Emscripten + backup/restore current state.
  24. // 2021-06-21: OpenGL: Destroy individual vertex/fragment shader objects right after they are linked into the main shader.
  25. // 2021-05-24: OpenGL: Access GL_CLIP_ORIGIN when "GL_ARB_clip_control" extension is detected, inside of just OpenGL 4.5 version.
  26. // 2021-05-19: OpenGL: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
  27. // 2021-04-06: OpenGL: Don't try to read GL_CLIP_ORIGIN unless we're OpenGL 4.5 or greater.
  28. // 2021-02-18: OpenGL: Change blending equation to preserve alpha in output buffer.
  29. // 2021-01-03: OpenGL: Backup, setup and restore GL_STENCIL_TEST state.
  30. // 2020-10-23: OpenGL: Backup, setup and restore GL_PRIMITIVE_RESTART state.
  31. // 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)
  32. // 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.
  33. // 2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
  34. // 2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
  35. // 2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by inverting projection matrix.
  36. // 2020-04-12: OpenGL: Fixed context version check mistakenly testing for 4.0+ instead of 3.2+ to enable ImGuiBackendFlags_RendererHasVtxOffset.
  37. // 2020-03-24: OpenGL: Added support for glbinding 2.x OpenGL loader.
  38. // 2020-01-07: OpenGL: Added support for glbinding 3.x OpenGL loader.
  39. // 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.
  40. // 2019-09-22: OpenGL: Detect default GL loader using __has_include compiler facility.
  41. // 2019-09-16: OpenGL: Tweak initialization code to allow application calling ImGui_ImplOpenGL3_CreateFontsTexture() before the first NewFrame() call.
  42. // 2019-05-29: OpenGL: Desktop GL only: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
  43. // 2019-04-30: OpenGL: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
  44. // 2019-03-29: OpenGL: Not calling glBindBuffer more than necessary in the render loop.
  45. // 2019-03-15: OpenGL: Added a GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early.
  46. // 2019-03-03: OpenGL: Fix support for ES 2.0 (WebGL 1.0).
  47. // 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.
  48. // 2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
  49. // 2019-02-01: OpenGL: Using GLSL 410 shaders for any version over 410 (e.g. 430, 450).
  50. // 2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
  51. // 2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT) / GL_CLIP_ORIGIN.
  52. // 2018-08-29: OpenGL: Added support for more OpenGL loaders: glew and glad, with comments indicative that any loader can be used.
  53. // 2018-08-09: OpenGL: Default to OpenGL ES 3 on iOS and Android. GLSL version default to "#version 300 ES".
  54. // 2018-07-30: OpenGL: Support for GLSL 300 ES and 410 core. Fixes for Emscripten compilation.
  55. // 2018-07-10: OpenGL: Support for more GLSL versions (based on the GLSL version string). Added error output when shaders fail to compile/link.
  56. // 2018-06-08: Misc: Extracted imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3 examples.
  57. // 2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
  58. // 2018-05-25: OpenGL: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
  59. // 2018-05-14: OpenGL: Making the call to glBindSampler() optional so 3.2 context won't fail if the function is a nullptr pointer.
  60. // 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".
  61. // 2018-02-23: OpenGL: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context.
  62. // 2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplSdlGL3_RenderDrawData() in the .h file so you can call it yourself.
  63. // 2018-01-07: OpenGL: Changed GLSL shader version from 330 to 150.
  64. // 2017-09-01: OpenGL: Save and restore current bound sampler. Save and restore current polygon mode.
  65. // 2017-05-01: OpenGL: Fixed save and restore of current blend func state.
  66. // 2017-05-01: OpenGL: Fixed save and restore of current GL_ACTIVE_TEXTURE.
  67. // 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
  68. // 2016-07-29: OpenGL: Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes it. (#752)
  69. //----------------------------------------
  70. // OpenGL GLSL GLSL
  71. // version version string
  72. //----------------------------------------
  73. // 2.0 110 "#version 110"
  74. // 2.1 120 "#version 120"
  75. // 3.0 130 "#version 130"
  76. // 3.1 140 "#version 140"
  77. // 3.2 150 "#version 150"
  78. // 3.3 330 "#version 330 core"
  79. // 4.0 400 "#version 400 core"
  80. // 4.1 410 "#version 410 core"
  81. // 4.2 420 "#version 410 core"
  82. // 4.3 430 "#version 430 core"
  83. // ES 2.0 100 "#version 100" = WebGL 1.0
  84. // ES 3.0 300 "#version 300 es" = WebGL 2.0
  85. //----------------------------------------
  86. #if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
  87. #define _CRT_SECURE_NO_WARNINGS
  88. #endif
  89. #include "imgui.h"
  90. #include "imgui_impl_opengl3.h"
  91. #include <stdio.h>
  92. #if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
  93. #include <stddef.h> // intptr_t
  94. #else
  95. #include <stdint.h> // intptr_t
  96. #endif
  97. #if defined(__APPLE__)
  98. #include <TargetConditionals.h>
  99. #endif
  100. // Clang warnings with -Weverything
  101. #if defined(__clang__)
  102. #pragma clang diagnostic push
  103. #pragma clang diagnostic ignored "-Wold-style-cast" // warning: use of old-style cast
  104. #pragma clang diagnostic ignored "-Wsign-conversion" // warning: implicit conversion changes signedness
  105. #endif
  106. // GL includes
  107. #if defined(IMGUI_IMPL_OPENGL_ES2)
  108. #if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
  109. #include <OpenGLES/ES2/gl.h> // Use GL ES 2
  110. #else
  111. #include <GLES2/gl2.h> // Use GL ES 2
  112. #endif
  113. #if defined(__EMSCRIPTEN__)
  114. #ifndef GL_GLEXT_PROTOTYPES
  115. #define GL_GLEXT_PROTOTYPES
  116. #endif
  117. #include <GLES2/gl2ext.h>
  118. #endif
  119. #elif defined(IMGUI_IMPL_OPENGL_ES3)
  120. #if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
  121. #include <OpenGLES/ES3/gl.h> // Use GL ES 3
  122. #else
  123. #include <GLES3/gl3.h> // Use GL ES 3
  124. #endif
  125. #elif !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
  126. // Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
  127. // Helper libraries are often used for this purpose! Here we are using our own minimal custom loader based on gl3w.
  128. // In the rest of your app/engine, you can use another loader of your choice (gl3w, glew, glad, glbinding, glext, glLoadGen, etc.).
  129. // If you happen to be developing a new feature for this backend (imgui_impl_opengl3.cpp):
  130. // - You may need to regenerate imgui_impl_opengl3_loader.h to add new symbols. See https://github.com/dearimgui/gl3w_stripped
  131. // - You can temporarily use an unstripped version. See https://github.com/dearimgui/gl3w_stripped/releases
  132. // Changes to this backend using new APIs should be accompanied by a regenerated stripped loader version.
  133. #define IMGL3W_IMPL
  134. #include "imgui_impl_opengl3_loader.h"
  135. #endif
  136. // Vertex arrays are not supported on ES2/WebGL1 unless Emscripten which uses an extension
  137. #ifndef IMGUI_IMPL_OPENGL_ES2
  138. #define IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  139. #elif defined(__EMSCRIPTEN__)
  140. #define IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  141. #define glBindVertexArray glBindVertexArrayOES
  142. #define glGenVertexArrays glGenVertexArraysOES
  143. #define glDeleteVertexArrays glDeleteVertexArraysOES
  144. #define GL_VERTEX_ARRAY_BINDING GL_VERTEX_ARRAY_BINDING_OES
  145. #endif
  146. // Desktop GL 2.0+ has glPolygonMode() which GL ES and WebGL don't have.
  147. #ifdef GL_POLYGON_MODE
  148. #define IMGUI_IMPL_HAS_POLYGON_MODE
  149. #endif
  150. // Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't have.
  151. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_2)
  152. #define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
  153. #endif
  154. // Desktop GL 3.3+ has glBindSampler()
  155. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_3)
  156. #define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
  157. #endif
  158. // Desktop GL 3.1+ has GL_PRIMITIVE_RESTART state
  159. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_1)
  160. #define IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
  161. #endif
  162. // Desktop GL use extension detection
  163. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3)
  164. #define IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
  165. #endif
  166. // [Debugging]
  167. //#define IMGUI_IMPL_OPENGL_DEBUG
  168. #ifdef IMGUI_IMPL_OPENGL_DEBUG
  169. #include <stdio.h>
  170. #define GL_CALL(_CALL) do { _CALL; GLenum gl_err = glGetError(); if (gl_err != 0) fprintf(stderr, "GL error 0x%x returned from '%s'.\n", gl_err, #_CALL); } while (0) // Call with error check
  171. #else
  172. #define GL_CALL(_CALL) _CALL // Call without error check
  173. #endif
  174. // OpenGL Data
  175. struct ImGui_ImplOpenGL3_Data
  176. {
  177. GLuint GlVersion; // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
  178. char GlslVersionString[32]; // Specified by user or detected based on compile time GL settings.
  179. GLuint FontTexture;
  180. GLuint ShaderHandle;
  181. GLint AttribLocationTex; // Uniforms location
  182. GLint AttribLocationProjMtx;
  183. GLuint AttribLocationVtxPos; // Vertex attributes location
  184. GLuint AttribLocationVtxUV;
  185. GLuint AttribLocationVtxColor;
  186. unsigned int VboHandle, ElementsHandle;
  187. GLsizeiptr VertexBufferSize;
  188. GLsizeiptr IndexBufferSize;
  189. bool HasClipOrigin;
  190. bool UseBufferSubData;
  191. ImGui_ImplOpenGL3_Data() { memset((void*)this, 0, sizeof(*this)); }
  192. };
  193. // Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
  194. // It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
  195. static ImGui_ImplOpenGL3_Data* ImGui_ImplOpenGL3_GetBackendData()
  196. {
  197. return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
  198. }
  199. // OpenGL vertex attribute state (for ES 1.0 and ES 2.0 only)
  200. #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  201. struct ImGui_ImplOpenGL3_VtxAttribState
  202. {
  203. GLint Enabled, Size, Type, Normalized, Stride;
  204. GLvoid* Ptr;
  205. void GetState(GLint index)
  206. {
  207. glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_ENABLED, &Enabled);
  208. glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_SIZE, &Size);
  209. glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_TYPE, &Type);
  210. glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_NORMALIZED, &Normalized);
  211. glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_STRIDE, &Stride);
  212. glGetVertexAttribPointerv(index, GL_VERTEX_ATTRIB_ARRAY_POINTER, &Ptr);
  213. }
  214. void SetState(GLint index)
  215. {
  216. glVertexAttribPointer(index, Size, Type, (GLboolean)Normalized, Stride, Ptr);
  217. if (Enabled) glEnableVertexAttribArray(index); else glDisableVertexAttribArray(index);
  218. }
  219. };
  220. #endif
  221. // Functions
  222. bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
  223. {
  224. ImGuiIO& io = ImGui::GetIO();
  225. IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
  226. // Initialize our loader
  227. #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
  228. if (imgl3wInit() != 0)
  229. {
  230. fprintf(stderr, "Failed to initialize OpenGL loader!\n");
  231. return false;
  232. }
  233. #endif
  234. // Setup backend capabilities flags
  235. ImGui_ImplOpenGL3_Data* bd = IM_NEW(ImGui_ImplOpenGL3_Data)();
  236. io.BackendRendererUserData = (void*)bd;
  237. io.BackendRendererName = "imgui_impl_opengl3";
  238. // Query for GL version (e.g. 320 for GL 3.2)
  239. #if !defined(IMGUI_IMPL_OPENGL_ES2)
  240. GLint major = 0;
  241. GLint minor = 0;
  242. glGetIntegerv(GL_MAJOR_VERSION, &major);
  243. glGetIntegerv(GL_MINOR_VERSION, &minor);
  244. if (major == 0 && minor == 0)
  245. {
  246. // Query GL_VERSION in desktop GL 2.x, the string will start with "<major>.<minor>"
  247. const char* gl_version = (const char*)glGetString(GL_VERSION);
  248. sscanf(gl_version, "%d.%d", &major, &minor);
  249. }
  250. bd->GlVersion = (GLuint)(major * 100 + minor * 10);
  251. bd->UseBufferSubData = false;
  252. /*
  253. // Query vendor to enable glBufferSubData kludge
  254. #ifdef _WIN32
  255. if (const char* vendor = (const char*)glGetString(GL_VENDOR))
  256. if (strncmp(vendor, "Intel", 5) == 0)
  257. bd->UseBufferSubData = true;
  258. #endif
  259. */
  260. #else
  261. bd->GlVersion = 200; // GLES 2
  262. #endif
  263. #ifdef IMGUI_IMPL_OPENGL_DEBUG
  264. printf("GL_MAJOR_VERSION = %d\nGL_MINOR_VERSION = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", major, minor, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
  265. #endif
  266. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
  267. if (bd->GlVersion >= 320)
  268. io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
  269. #endif
  270. // Store GLSL version string so we can refer to it later in case we recreate shaders.
  271. // Note: GLSL version is NOT the same as GL version. Leave this to nullptr if unsure.
  272. if (glsl_version == nullptr)
  273. {
  274. #if defined(IMGUI_IMPL_OPENGL_ES2)
  275. glsl_version = "#version 100";
  276. #elif defined(IMGUI_IMPL_OPENGL_ES3)
  277. glsl_version = "#version 300 es";
  278. #elif defined(__APPLE__)
  279. glsl_version = "#version 150";
  280. #else
  281. glsl_version = "#version 130";
  282. #endif
  283. }
  284. IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(bd->GlslVersionString));
  285. strcpy(bd->GlslVersionString, glsl_version);
  286. strcat(bd->GlslVersionString, "\n");
  287. // Make an arbitrary GL call (we don't actually need the result)
  288. // IF YOU GET A CRASH HERE: it probably means the OpenGL function loader didn't do its job. Let us know!
  289. GLint current_texture;
  290. glGetIntegerv(GL_TEXTURE_BINDING_2D, &current_texture);
  291. // Detect extensions we support
  292. bd->HasClipOrigin = (bd->GlVersion >= 450);
  293. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
  294. GLint num_extensions = 0;
  295. glGetIntegerv(GL_NUM_EXTENSIONS, &num_extensions);
  296. for (GLint i = 0; i < num_extensions; i++)
  297. {
  298. const char* extension = (const char*)glGetStringi(GL_EXTENSIONS, i);
  299. if (extension != nullptr && strcmp(extension, "GL_ARB_clip_control") == 0)
  300. bd->HasClipOrigin = true;
  301. }
  302. #endif
  303. return true;
  304. }
  305. void ImGui_ImplOpenGL3_Shutdown()
  306. {
  307. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  308. IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
  309. ImGuiIO& io = ImGui::GetIO();
  310. ImGui_ImplOpenGL3_DestroyDeviceObjects();
  311. io.BackendRendererName = nullptr;
  312. io.BackendRendererUserData = nullptr;
  313. IM_DELETE(bd);
  314. }
  315. void ImGui_ImplOpenGL3_NewFrame()
  316. {
  317. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  318. IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplOpenGL3_Init()?");
  319. if (!bd->ShaderHandle)
  320. ImGui_ImplOpenGL3_CreateDeviceObjects();
  321. }
  322. static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height, GLuint vertex_array_object)
  323. {
  324. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  325. // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
  326. glEnable(GL_BLEND);
  327. glBlendEquation(GL_FUNC_ADD);
  328. glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
  329. glDisable(GL_CULL_FACE);
  330. glDisable(GL_DEPTH_TEST);
  331. glDisable(GL_STENCIL_TEST);
  332. glEnable(GL_SCISSOR_TEST);
  333. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
  334. if (bd->GlVersion >= 310)
  335. glDisable(GL_PRIMITIVE_RESTART);
  336. #endif
  337. #ifdef IMGUI_IMPL_HAS_POLYGON_MODE
  338. glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
  339. #endif
  340. // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT)
  341. #if defined(GL_CLIP_ORIGIN)
  342. bool clip_origin_lower_left = true;
  343. if (bd->HasClipOrigin)
  344. {
  345. GLenum current_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)&current_clip_origin);
  346. if (current_clip_origin == GL_UPPER_LEFT)
  347. clip_origin_lower_left = false;
  348. }
  349. #endif
  350. // Setup viewport, orthographic projection matrix
  351. // 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.
  352. GL_CALL(glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height));
  353. float L = draw_data->DisplayPos.x;
  354. float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
  355. float T = draw_data->DisplayPos.y;
  356. float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
  357. #if defined(GL_CLIP_ORIGIN)
  358. if (!clip_origin_lower_left) { float tmp = T; T = B; B = tmp; } // Swap top and bottom if origin is upper left
  359. #endif
  360. const float ortho_projection[4][4] =
  361. {
  362. { 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
  363. { 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
  364. { 0.0f, 0.0f, -1.0f, 0.0f },
  365. { (R+L)/(L-R), (T+B)/(B-T), 0.0f, 1.0f },
  366. };
  367. glUseProgram(bd->ShaderHandle);
  368. glUniform1i(bd->AttribLocationTex, 0);
  369. glUniformMatrix4fv(bd->AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
  370. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
  371. if (bd->GlVersion >= 330)
  372. glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
  373. #endif
  374. (void)vertex_array_object;
  375. #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  376. glBindVertexArray(vertex_array_object);
  377. #endif
  378. // Bind vertex/index buffers and setup attributes for ImDrawVert
  379. GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, bd->VboHandle));
  380. GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bd->ElementsHandle));
  381. GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxPos));
  382. GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxUV));
  383. GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxColor));
  384. GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos)));
  385. GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv)));
  386. GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col)));
  387. }
  388. // OpenGL3 Render function.
  389. // Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly.
  390. // This is in order to be able to run within an OpenGL engine that doesn't do so.
  391. void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
  392. {
  393. // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
  394. int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
  395. int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
  396. if (fb_width <= 0 || fb_height <= 0)
  397. return;
  398. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  399. // Backup GL state
  400. GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
  401. glActiveTexture(GL_TEXTURE0);
  402. GLuint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&last_program);
  403. GLuint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint*)&last_texture);
  404. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
  405. GLuint last_sampler; if (bd->GlVersion >= 330) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
  406. #endif
  407. GLuint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint*)&last_array_buffer);
  408. #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  409. // This is part of VAO on OpenGL 3.0+ and OpenGL ES 3.0+.
  410. GLint last_element_array_buffer; glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer);
  411. ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_pos; last_vtx_attrib_state_pos.GetState(bd->AttribLocationVtxPos);
  412. ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_uv; last_vtx_attrib_state_uv.GetState(bd->AttribLocationVtxUV);
  413. ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_color; last_vtx_attrib_state_color.GetState(bd->AttribLocationVtxColor);
  414. #endif
  415. #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  416. GLuint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, (GLint*)&last_vertex_array_object);
  417. #endif
  418. #ifdef IMGUI_IMPL_HAS_POLYGON_MODE
  419. GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
  420. #endif
  421. GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
  422. GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
  423. GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb);
  424. GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb);
  425. GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha);
  426. GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha);
  427. GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb);
  428. GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha);
  429. GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
  430. GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
  431. GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
  432. GLboolean last_enable_stencil_test = glIsEnabled(GL_STENCIL_TEST);
  433. GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
  434. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
  435. GLboolean last_enable_primitive_restart = (bd->GlVersion >= 310) ? glIsEnabled(GL_PRIMITIVE_RESTART) : GL_FALSE;
  436. #endif
  437. // Setup desired GL state
  438. // Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
  439. // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
  440. GLuint vertex_array_object = 0;
  441. #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  442. GL_CALL(glGenVertexArrays(1, &vertex_array_object));
  443. #endif
  444. ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
  445. // Will project scissor/clipping rectangles into framebuffer space
  446. ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
  447. ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
  448. // Render command lists
  449. for (int n = 0; n < draw_data->CmdListsCount; n++)
  450. {
  451. const ImDrawList* cmd_list = draw_data->CmdLists[n];
  452. // Upload vertex/index buffers
  453. // - OpenGL drivers are in a very sorry state nowadays....
  454. // During 2021 we attempted to switch from glBufferData() to orphaning+glBufferSubData() following reports
  455. // of leaks on Intel GPU when using multi-viewports on Windows.
  456. // - After this we kept hearing of various display corruptions issues. We started disabling on non-Intel GPU, but issues still got reported on Intel.
  457. // - We are now back to using exclusively glBufferData(). So bd->UseBufferSubData IS ALWAYS FALSE in this code.
  458. // We are keeping the old code path for a while in case people finding new issues may want to test the bd->UseBufferSubData path.
  459. // - See https://github.com/ocornut/imgui/issues/4468 and please report any corruption issues.
  460. const GLsizeiptr vtx_buffer_size = (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert);
  461. const GLsizeiptr idx_buffer_size = (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx);
  462. if (bd->UseBufferSubData)
  463. {
  464. if (bd->VertexBufferSize < vtx_buffer_size)
  465. {
  466. bd->VertexBufferSize = vtx_buffer_size;
  467. GL_CALL(glBufferData(GL_ARRAY_BUFFER, bd->VertexBufferSize, nullptr, GL_STREAM_DRAW));
  468. }
  469. if (bd->IndexBufferSize < idx_buffer_size)
  470. {
  471. bd->IndexBufferSize = idx_buffer_size;
  472. GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, bd->IndexBufferSize, nullptr, GL_STREAM_DRAW));
  473. }
  474. GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data));
  475. GL_CALL(glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data));
  476. }
  477. else
  478. {
  479. GL_CALL(glBufferData(GL_ARRAY_BUFFER, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW));
  480. GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW));
  481. }
  482. for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
  483. {
  484. const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
  485. if (pcmd->UserCallback != nullptr)
  486. {
  487. // User callback, registered via ImDrawList::AddCallback()
  488. // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
  489. if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
  490. ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
  491. else
  492. pcmd->UserCallback(cmd_list, pcmd);
  493. }
  494. else
  495. {
  496. // Project scissor/clipping rectangles into framebuffer space
  497. ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
  498. ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
  499. if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
  500. continue;
  501. // Apply scissor/clipping rectangle (Y is inverted in OpenGL)
  502. GL_CALL(glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y)));
  503. // Bind texture, Draw
  504. GL_CALL(glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID()));
  505. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
  506. if (bd->GlVersion >= 320)
  507. GL_CALL(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));
  508. else
  509. #endif
  510. GL_CALL(glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))));
  511. }
  512. }
  513. }
  514. // Destroy the temporary VAO
  515. #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  516. GL_CALL(glDeleteVertexArrays(1, &vertex_array_object));
  517. #endif
  518. // Restore modified GL state
  519. glUseProgram(last_program);
  520. glBindTexture(GL_TEXTURE_2D, last_texture);
  521. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
  522. if (bd->GlVersion >= 330)
  523. glBindSampler(0, last_sampler);
  524. #endif
  525. glActiveTexture(last_active_texture);
  526. #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  527. glBindVertexArray(last_vertex_array_object);
  528. #endif
  529. glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
  530. #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  531. glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, last_element_array_buffer);
  532. last_vtx_attrib_state_pos.SetState(bd->AttribLocationVtxPos);
  533. last_vtx_attrib_state_uv.SetState(bd->AttribLocationVtxUV);
  534. last_vtx_attrib_state_color.SetState(bd->AttribLocationVtxColor);
  535. #endif
  536. glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
  537. glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
  538. if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
  539. if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
  540. if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
  541. if (last_enable_stencil_test) glEnable(GL_STENCIL_TEST); else glDisable(GL_STENCIL_TEST);
  542. if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
  543. #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
  544. if (bd->GlVersion >= 310) { if (last_enable_primitive_restart) glEnable(GL_PRIMITIVE_RESTART); else glDisable(GL_PRIMITIVE_RESTART); }
  545. #endif
  546. #ifdef IMGUI_IMPL_HAS_POLYGON_MODE
  547. glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
  548. #endif
  549. glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
  550. glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
  551. (void)bd; // Not all compilation paths use this
  552. }
  553. bool ImGui_ImplOpenGL3_CreateFontsTexture()
  554. {
  555. ImGuiIO& io = ImGui::GetIO();
  556. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  557. // Build texture atlas
  558. unsigned char* pixels;
  559. int width, height;
  560. 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.
  561. // Upload texture to graphics system
  562. // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
  563. GLint last_texture;
  564. GL_CALL(glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture));
  565. GL_CALL(glGenTextures(1, &bd->FontTexture));
  566. GL_CALL(glBindTexture(GL_TEXTURE_2D, bd->FontTexture));
  567. GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
  568. GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
  569. #ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
  570. GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
  571. #endif
  572. GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels));
  573. // Store our identifier
  574. io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
  575. // Restore state
  576. GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture));
  577. return true;
  578. }
  579. void ImGui_ImplOpenGL3_DestroyFontsTexture()
  580. {
  581. ImGuiIO& io = ImGui::GetIO();
  582. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  583. if (bd->FontTexture)
  584. {
  585. glDeleteTextures(1, &bd->FontTexture);
  586. io.Fonts->SetTexID(0);
  587. bd->FontTexture = 0;
  588. }
  589. }
  590. // 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.
  591. static bool CheckShader(GLuint handle, const char* desc)
  592. {
  593. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  594. GLint status = 0, log_length = 0;
  595. glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
  596. glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
  597. if ((GLboolean)status == GL_FALSE)
  598. fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile %s! With GLSL: %s\n", desc, bd->GlslVersionString);
  599. if (log_length > 1)
  600. {
  601. ImVector<char> buf;
  602. buf.resize((int)(log_length + 1));
  603. glGetShaderInfoLog(handle, log_length, nullptr, (GLchar*)buf.begin());
  604. fprintf(stderr, "%s\n", buf.begin());
  605. }
  606. return (GLboolean)status == GL_TRUE;
  607. }
  608. // If you get an error please report on GitHub. You may try different GL context version or GLSL version.
  609. static bool CheckProgram(GLuint handle, const char* desc)
  610. {
  611. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  612. GLint status = 0, log_length = 0;
  613. glGetProgramiv(handle, GL_LINK_STATUS, &status);
  614. glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
  615. if ((GLboolean)status == GL_FALSE)
  616. fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! With GLSL %s\n", desc, bd->GlslVersionString);
  617. if (log_length > 1)
  618. {
  619. ImVector<char> buf;
  620. buf.resize((int)(log_length + 1));
  621. glGetProgramInfoLog(handle, log_length, nullptr, (GLchar*)buf.begin());
  622. fprintf(stderr, "%s\n", buf.begin());
  623. }
  624. return (GLboolean)status == GL_TRUE;
  625. }
  626. bool ImGui_ImplOpenGL3_CreateDeviceObjects()
  627. {
  628. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  629. // Backup GL state
  630. GLint last_texture, last_array_buffer;
  631. glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
  632. glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
  633. #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  634. GLint last_vertex_array;
  635. glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
  636. #endif
  637. // Parse GLSL version string
  638. int glsl_version = 130;
  639. sscanf(bd->GlslVersionString, "#version %d", &glsl_version);
  640. const GLchar* vertex_shader_glsl_120 =
  641. "uniform mat4 ProjMtx;\n"
  642. "attribute vec2 Position;\n"
  643. "attribute vec2 UV;\n"
  644. "attribute vec4 Color;\n"
  645. "varying vec2 Frag_UV;\n"
  646. "varying vec4 Frag_Color;\n"
  647. "void main()\n"
  648. "{\n"
  649. " Frag_UV = UV;\n"
  650. " Frag_Color = Color;\n"
  651. " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
  652. "}\n";
  653. const GLchar* vertex_shader_glsl_130 =
  654. "uniform mat4 ProjMtx;\n"
  655. "in vec2 Position;\n"
  656. "in vec2 UV;\n"
  657. "in vec4 Color;\n"
  658. "out vec2 Frag_UV;\n"
  659. "out vec4 Frag_Color;\n"
  660. "void main()\n"
  661. "{\n"
  662. " Frag_UV = UV;\n"
  663. " Frag_Color = Color;\n"
  664. " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
  665. "}\n";
  666. const GLchar* vertex_shader_glsl_300_es =
  667. "precision highp float;\n"
  668. "layout (location = 0) in vec2 Position;\n"
  669. "layout (location = 1) in vec2 UV;\n"
  670. "layout (location = 2) in vec4 Color;\n"
  671. "uniform mat4 ProjMtx;\n"
  672. "out vec2 Frag_UV;\n"
  673. "out vec4 Frag_Color;\n"
  674. "void main()\n"
  675. "{\n"
  676. " Frag_UV = UV;\n"
  677. " Frag_Color = Color;\n"
  678. " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
  679. "}\n";
  680. const GLchar* vertex_shader_glsl_410_core =
  681. "layout (location = 0) in vec2 Position;\n"
  682. "layout (location = 1) in vec2 UV;\n"
  683. "layout (location = 2) in vec4 Color;\n"
  684. "uniform mat4 ProjMtx;\n"
  685. "out vec2 Frag_UV;\n"
  686. "out vec4 Frag_Color;\n"
  687. "void main()\n"
  688. "{\n"
  689. " Frag_UV = UV;\n"
  690. " Frag_Color = Color;\n"
  691. " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
  692. "}\n";
  693. const GLchar* fragment_shader_glsl_120 =
  694. "#ifdef GL_ES\n"
  695. " precision mediump float;\n"
  696. "#endif\n"
  697. "uniform sampler2D Texture;\n"
  698. "varying vec2 Frag_UV;\n"
  699. "varying vec4 Frag_Color;\n"
  700. "void main()\n"
  701. "{\n"
  702. " gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
  703. "}\n";
  704. const GLchar* fragment_shader_glsl_130 =
  705. "uniform sampler2D Texture;\n"
  706. "in vec2 Frag_UV;\n"
  707. "in vec4 Frag_Color;\n"
  708. "out vec4 Out_Color;\n"
  709. "void main()\n"
  710. "{\n"
  711. " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
  712. "}\n";
  713. const GLchar* fragment_shader_glsl_300_es =
  714. "precision mediump float;\n"
  715. "uniform sampler2D Texture;\n"
  716. "in vec2 Frag_UV;\n"
  717. "in vec4 Frag_Color;\n"
  718. "layout (location = 0) out vec4 Out_Color;\n"
  719. "void main()\n"
  720. "{\n"
  721. " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
  722. "}\n";
  723. const GLchar* fragment_shader_glsl_410_core =
  724. "in vec2 Frag_UV;\n"
  725. "in vec4 Frag_Color;\n"
  726. "uniform sampler2D Texture;\n"
  727. "layout (location = 0) out vec4 Out_Color;\n"
  728. "void main()\n"
  729. "{\n"
  730. " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
  731. "}\n";
  732. // Select shaders matching our GLSL versions
  733. const GLchar* vertex_shader = nullptr;
  734. const GLchar* fragment_shader = nullptr;
  735. if (glsl_version < 130)
  736. {
  737. vertex_shader = vertex_shader_glsl_120;
  738. fragment_shader = fragment_shader_glsl_120;
  739. }
  740. else if (glsl_version >= 410)
  741. {
  742. vertex_shader = vertex_shader_glsl_410_core;
  743. fragment_shader = fragment_shader_glsl_410_core;
  744. }
  745. else if (glsl_version == 300)
  746. {
  747. vertex_shader = vertex_shader_glsl_300_es;
  748. fragment_shader = fragment_shader_glsl_300_es;
  749. }
  750. else
  751. {
  752. vertex_shader = vertex_shader_glsl_130;
  753. fragment_shader = fragment_shader_glsl_130;
  754. }
  755. // Create shaders
  756. const GLchar* vertex_shader_with_version[2] = { bd->GlslVersionString, vertex_shader };
  757. GLuint vert_handle = glCreateShader(GL_VERTEX_SHADER);
  758. glShaderSource(vert_handle, 2, vertex_shader_with_version, nullptr);
  759. glCompileShader(vert_handle);
  760. CheckShader(vert_handle, "vertex shader");
  761. const GLchar* fragment_shader_with_version[2] = { bd->GlslVersionString, fragment_shader };
  762. GLuint frag_handle = glCreateShader(GL_FRAGMENT_SHADER);
  763. glShaderSource(frag_handle, 2, fragment_shader_with_version, nullptr);
  764. glCompileShader(frag_handle);
  765. CheckShader(frag_handle, "fragment shader");
  766. // Link
  767. bd->ShaderHandle = glCreateProgram();
  768. glAttachShader(bd->ShaderHandle, vert_handle);
  769. glAttachShader(bd->ShaderHandle, frag_handle);
  770. glLinkProgram(bd->ShaderHandle);
  771. CheckProgram(bd->ShaderHandle, "shader program");
  772. glDetachShader(bd->ShaderHandle, vert_handle);
  773. glDetachShader(bd->ShaderHandle, frag_handle);
  774. glDeleteShader(vert_handle);
  775. glDeleteShader(frag_handle);
  776. bd->AttribLocationTex = glGetUniformLocation(bd->ShaderHandle, "Texture");
  777. bd->AttribLocationProjMtx = glGetUniformLocation(bd->ShaderHandle, "ProjMtx");
  778. bd->AttribLocationVtxPos = (GLuint)glGetAttribLocation(bd->ShaderHandle, "Position");
  779. bd->AttribLocationVtxUV = (GLuint)glGetAttribLocation(bd->ShaderHandle, "UV");
  780. bd->AttribLocationVtxColor = (GLuint)glGetAttribLocation(bd->ShaderHandle, "Color");
  781. // Create buffers
  782. glGenBuffers(1, &bd->VboHandle);
  783. glGenBuffers(1, &bd->ElementsHandle);
  784. ImGui_ImplOpenGL3_CreateFontsTexture();
  785. // Restore modified GL state
  786. glBindTexture(GL_TEXTURE_2D, last_texture);
  787. glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
  788. #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
  789. glBindVertexArray(last_vertex_array);
  790. #endif
  791. return true;
  792. }
  793. void ImGui_ImplOpenGL3_DestroyDeviceObjects()
  794. {
  795. ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
  796. if (bd->VboHandle) { glDeleteBuffers(1, &bd->VboHandle); bd->VboHandle = 0; }
  797. if (bd->ElementsHandle) { glDeleteBuffers(1, &bd->ElementsHandle); bd->ElementsHandle = 0; }
  798. if (bd->ShaderHandle) { glDeleteProgram(bd->ShaderHandle); bd->ShaderHandle = 0; }
  799. ImGui_ImplOpenGL3_DestroyFontsTexture();
  800. }
  801. #if defined(__clang__)
  802. #pragma clang diagnostic pop
  803. #endif