1 // dear imgui: Renderer 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 Binding (e.g. GLFW, SDL, Win32, custom..)
5
6 // Implemented features:
7 // [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
8 // [X] Renderer: Multi-viewport support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
9 // [x] Renderer: Desktop GL only: Support for large meshes (64k+ vertices) with 16-bit indices.
10
11 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
12 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
13 // https://github.com/ocornut/imgui
14
15 // CHANGELOG
16 // (minor and older changes stripped away, please see git history for details)
17 // 2020-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
18 // 2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
19 // 2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
20 // 2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by inverting projection matrix.
21 // 2020-04-12: OpenGL: Fixed context version check mistakenly testing for 4.0+ instead of 3.2+ to enable ImGuiBackendFlags_RendererHasVtxOffset.
22 // 2020-03-24: OpenGL: Added support for glbinding 2.x OpenGL loader.
23 // 2020-01-07: OpenGL: Added support for glbinding 3.x OpenGL loader.
24 // 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.
25 // 2019-09-22: OpenGL: Detect default GL loader using __has_include compiler facility.
26 // 2019-09-16: OpenGL: Tweak initialization code to allow application calling ImGui_ImplOpenGL3_CreateFontsTexture() before the first NewFrame() call.
27 // 2019-05-29: OpenGL: Desktop GL only: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
28 // 2019-04-30: OpenGL: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
29 // 2019-03-29: OpenGL: Not calling glBindBuffer more than necessary in the render loop.
30 // 2019-03-15: OpenGL: Added a GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early.
31 // 2019-03-03: OpenGL: Fix support for ES 2.0 (WebGL 1.0).
32 // 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.
33 // 2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
34 // 2019-02-01: OpenGL: Using GLSL 410 shaders for any version over 410 (e.g. 430, 450).
35 // 2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
36 // 2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT) / GL_CLIP_ORIGIN.
37 // 2018-08-29: OpenGL: Added support for more OpenGL loaders: glew and glad, with comments indicative that any loader can be used.
38 // 2018-08-09: OpenGL: Default to OpenGL ES 3 on iOS and Android. GLSL version default to "#version 300 ES".
39 // 2018-07-30: OpenGL: Support for GLSL 300 ES and 410 core. Fixes for Emscripten compilation.
40 // 2018-07-10: OpenGL: Support for more GLSL versions (based on the GLSL version string). Added error output when shaders fail to compile/link.
41 // 2018-06-08: Misc: Extracted imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3 examples.
42 // 2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
43 // 2018-05-25: OpenGL: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
44 // 2018-05-14: OpenGL: Making the call to glBindSampler() optional so 3.2 context won't fail if the function is a NULL pointer.
45 // 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".
46 // 2018-02-23: OpenGL: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context.
47 // 2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplSdlGL3_RenderDrawData() in the .h file so you can call it yourself.
48 // 2018-01-07: OpenGL: Changed GLSL shader version from 330 to 150.
49 // 2017-09-01: OpenGL: Save and restore current bound sampler. Save and restore current polygon mode.
50 // 2017-05-01: OpenGL: Fixed save and restore of current blend func state.
51 // 2017-05-01: OpenGL: Fixed save and restore of current GL_ACTIVE_TEXTURE.
52 // 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
53 // 2016-07-29: OpenGL: Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes it. (#752)
54
55 //----------------------------------------
56 // OpenGL GLSL GLSL
57 // version version string
58 //----------------------------------------
59 // 2.0 110 "#version 110"
60 // 2.1 120 "#version 120"
61 // 3.0 130 "#version 130"
62 // 3.1 140 "#version 140"
63 // 3.2 150 "#version 150"
64 // 3.3 330 "#version 330 core"
65 // 4.0 400 "#version 400 core"
66 // 4.1 410 "#version 410 core"
67 // 4.2 420 "#version 410 core"
68 // 4.3 430 "#version 430 core"
69 // ES 2.0 100 "#version 100" = WebGL 1.0
70 // ES 3.0 300 "#version 300 es" = WebGL 2.0
71 //----------------------------------------
72
73 #if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
74 #define _CRT_SECURE_NO_WARNINGS
75 #endif
76
77 #include "imgui.h"
78 #include "imgui_impl_opengl3.h"
79 #include <stdio.h>
80 #if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
81 #include <stddef.h> // intptr_t
82 #else
83 #include <stdint.h> // intptr_t
84 #endif
85
86 #if defined(__APPLE__)
87 #include "TargetConditionals.h"
88 #endif
89
90 // [Bruno Levy] Auto-enable GLES on matching platforms, copied from previous version
91 #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3)
92 #if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV)) || (defined(__ANDROID__))
93 #define IMGUI_IMPL_OPENGL_ES3 // iOS, Android -> GL ES 3, "#version 300 es"
94 #undef IMGUI_IMPL_OPENGL_LOADER_GL3W
95 #undef IMGUI_IMPL_OPENGL_LOADER_GLEW
96 #undef IMGUI_IMPL_OPENGL_LOADER_GLAD
97 #undef IMGUI_IMPL_OPENGL_LOADER_GLBINDING
98 #undef IMGUI_IMPL_OPENGL_LOADER_CUSTOM
99 #elif defined(__EMSCRIPTEN__)
100 #define IMGUI_IMPL_OPENGL_ES2 // Emscripten -> GL ES 2, "#version 100"
101 #undef IMGUI_IMPL_OPENGL_LOADER_GL3W
102 #undef IMGUI_IMPL_OPENGL_LOADER_GLEW
103 #undef IMGUI_IMPL_OPENGL_LOADER_GLAD
104 #undef IMGUI_IMPL_OPENGL_LOADER_GLBINDING
105 #undef IMGUI_IMPL_OPENGL_LOADER_CUSTOM
106 #endif
107 #endif
108 // end [Bruno Levy]
109
110 // GL includes
111 #if defined(IMGUI_IMPL_OPENGL_ES2)
112 #include <GLES2/gl2.h>
113 #elif defined(IMGUI_IMPL_OPENGL_ES3)
114 #if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
115 #include <OpenGLES/ES3/gl.h> // Use GL ES 3
116 #else
117 #include <GLES3/gl3.h> // Use GL ES 3
118 #endif
119 #else
120 // About Desktop OpenGL function loaders:
121 // Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
122 // Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad).
123 // You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.
124 #if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
125 #include <GL/gl3w.h> // Needs to be initialized with gl3wInit() in user's code
126 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
127 #include <GL/glew.h> // Needs to be initialized with glewInit() in user's code.
128 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
129 #include <glad/glad.h> // Needs to be initialized with gladLoadGL() in user's code.
130 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
131 #include <glad/gl.h> // Needs to be initialized with gladLoadGL(...) or gladLoaderLoadGL() in user's code.
132 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
133 #ifndef GLFW_INCLUDE_NONE
134 #define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
135 #endif
136 #include <glbinding/Binding.h> // Needs to be initialized with glbinding::Binding::initialize() in user's code.
137 #include <glbinding/gl/gl.h>
138 using namespace gl;
139 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
140 #ifndef GLFW_INCLUDE_NONE
141 #define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
142 #endif
143 #include <glbinding/glbinding.h>// Needs to be initialized with glbinding::initialize() in user's code.
144 #include <glbinding/gl/gl.h>
145 using namespace gl;
146 #else
147 #include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
148 #endif
149 #endif
150
151 // Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't have.
152 #if defined(IMGUI_IMPL_OPENGL_ES2) || defined(IMGUI_IMPL_OPENGL_ES3) || !defined(GL_VERSION_3_2)
153 #define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET 0
154 #else
155 #define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET 1
156 #endif
157
158 // OpenGL Data
159 static GLuint g_GlVersion = 0; // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
160 static char g_GlslVersionString[32] = ""; // Specified by user or detected based on compile time GL settings.
161 static GLuint g_FontTexture = 0;
162 static GLuint g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
163 static GLint g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; // Uniforms location
164 static GLuint g_AttribLocationVtxPos = 0, g_AttribLocationVtxUV = 0, g_AttribLocationVtxColor = 0; // Vertex attributes location
165 static unsigned int g_VboHandle = 0, g_ElementsHandle = 0;
166
167 // Forward Declarations
168 static void ImGui_ImplOpenGL3_InitPlatformInterface();
169 static void ImGui_ImplOpenGL3_ShutdownPlatformInterface();
170
171 // Functions
ImGui_ImplOpenGL3_Init(const char * glsl_version)172 bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
173 {
174 // Query for GL version (e.g. 320 for GL 3.2)
175 #if !defined(IMGUI_IMPL_OPENGL_ES2)
176 GLint major, minor;
177 glGetIntegerv(GL_MAJOR_VERSION, &major);
178 glGetIntegerv(GL_MINOR_VERSION, &minor);
179 g_GlVersion = (GLuint)(major * 100 + minor * 10);
180 #else
181 g_GlVersion = 200; // GLES 2
182 #endif
183
184 // Setup back-end capabilities flags
185 ImGuiIO& io = ImGui::GetIO();
186 io.BackendRendererName = "imgui_impl_opengl3";
187 #if IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
188 if (g_GlVersion >= 320)
189 io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
190 #endif
191 io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports; // We can create multi-viewports on the Renderer side (optional)
192
193 // Store GLSL version string so we can refer to it later in case we recreate shaders.
194 // Note: GLSL version is NOT the same as GL version. Leave this to NULL if unsure.
195 #if defined(IMGUI_IMPL_OPENGL_ES2)
196 if (glsl_version == NULL)
197 glsl_version = "#version 100";
198 #elif defined(IMGUI_IMPL_OPENGL_ES3)
199 if (glsl_version == NULL)
200 glsl_version = "#version 300 es";
201 #elif defined(__APPLE__)
202 if (glsl_version == NULL)
203 glsl_version = "#version 150";
204 #else
205 if (glsl_version == NULL)
206 glsl_version = "#version 130";
207 #endif
208 IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(g_GlslVersionString));
209 strcpy(g_GlslVersionString, glsl_version);
210 strcat(g_GlslVersionString, "\n");
211
212 // Debugging construct to make it easily visible in the IDE and debugger which GL loader has been selected.
213 // The code actually never uses the 'gl_loader' variable! It is only here so you can read it!
214 // If auto-detection fails or doesn't select the same GL loader file as used by your application,
215 // you are likely to get a crash below.
216 // You can explicitly select a loader by using '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
217 const char* gl_loader = "Unknown";
218 IM_UNUSED(gl_loader);
219 #if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
220 gl_loader = "GL3W";
221 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
222 gl_loader = "GLEW";
223 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
224 gl_loader = "GLAD";
225 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
226 gl_loader = "GLAD2";
227 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
228 gl_loader = "glbinding2";
229 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
230 gl_loader = "glbinding3";
231 #elif defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
232 gl_loader = "custom";
233 #else
234 gl_loader = "none";
235 #endif
236
237 // Make an arbitrary GL call (we don't actually need the result)
238 // IF YOU GET A CRASH HERE: it probably means that you haven't initialized the OpenGL function loader used by this code.
239 // Desktop OpenGL 3/4 need a function loader. See the IMGUI_IMPL_OPENGL_LOADER_xxx explanation above.
240 GLint current_texture;
241 glGetIntegerv(GL_TEXTURE_BINDING_2D, ¤t_texture);
242
243 if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
244 ImGui_ImplOpenGL3_InitPlatformInterface();
245
246 return true;
247 }
248
ImGui_ImplOpenGL3_Shutdown()249 void ImGui_ImplOpenGL3_Shutdown()
250 {
251 ImGui_ImplOpenGL3_ShutdownPlatformInterface();
252 ImGui_ImplOpenGL3_DestroyDeviceObjects();
253 }
254
ImGui_ImplOpenGL3_NewFrame()255 void ImGui_ImplOpenGL3_NewFrame()
256 {
257 if (!g_ShaderHandle)
258 ImGui_ImplOpenGL3_CreateDeviceObjects();
259 }
260
ImGui_ImplOpenGL3_SetupRenderState(ImDrawData * draw_data,int fb_width,int fb_height,GLuint vertex_array_object)261 static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height, GLuint vertex_array_object)
262 {
263 // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
264 glEnable(GL_BLEND);
265 glBlendEquation(GL_FUNC_ADD);
266 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
267 glDisable(GL_CULL_FACE);
268 glDisable(GL_DEPTH_TEST);
269 glEnable(GL_SCISSOR_TEST);
270 #ifdef GL_POLYGON_MODE
271 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
272 #endif
273
274 // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT)
275 bool clip_origin_lower_left = true;
276 #if defined(GL_CLIP_ORIGIN) && !defined(__APPLE__)
277 GLenum current_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)¤t_clip_origin);
278 if (current_clip_origin == GL_UPPER_LEFT)
279 clip_origin_lower_left = false;
280 #endif
281
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 (!clip_origin_lower_left) { float tmp = T; T = B; B = tmp; } // Swap top and bottom if origin is upper left
290 const float ortho_projection[4][4] =
291 {
292 { 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
293 { 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
294 { 0.0f, 0.0f, -1.0f, 0.0f },
295 { (R+L)/(L-R), (T+B)/(B-T), 0.0f, 1.0f },
296 };
297 glUseProgram(g_ShaderHandle);
298 glUniform1i(g_AttribLocationTex, 0);
299 glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
300 #ifdef GL_SAMPLER_BINDING
301 glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
302 #endif
303
304 (void)vertex_array_object;
305 #ifndef IMGUI_IMPL_OPENGL_ES2
306 glBindVertexArray(vertex_array_object);
307 #endif
308
309 // Bind vertex/index buffers and setup attributes for ImDrawVert
310 glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
311 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle);
312 glEnableVertexAttribArray(g_AttribLocationVtxPos);
313 glEnableVertexAttribArray(g_AttribLocationVtxUV);
314 glEnableVertexAttribArray(g_AttribLocationVtxColor);
315 glVertexAttribPointer(g_AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos));
316 glVertexAttribPointer(g_AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
317 glVertexAttribPointer(g_AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
318 }
319
320 // OpenGL3 Render function.
321 // (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
322 // Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly, in order to be able to run within any OpenGL engine that doesn't do so.
ImGui_ImplOpenGL3_RenderDrawData(ImDrawData * draw_data)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
331 // Backup GL state
332 GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
333 glActiveTexture(GL_TEXTURE0);
334 GLuint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&last_program);
335 GLuint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint*)&last_texture);
336 #ifdef GL_SAMPLER_BINDING
337 GLuint last_sampler; glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler);
338 #endif
339 GLuint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint*)&last_array_buffer);
340 #ifndef IMGUI_IMPL_OPENGL_ES2
341 GLuint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, (GLint*)&last_vertex_array_object);
342 #endif
343 #ifdef GL_POLYGON_MODE
344 GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
345 #endif
346 GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
347 GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
348 GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb);
349 GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb);
350 GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha);
351 GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha);
352 GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb);
353 GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha);
354 GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
355 GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
356 GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
357 GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
358
359 // Setup desired GL state
360 // Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
361 // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
362 GLuint vertex_array_object = 0;
363 #ifndef IMGUI_IMPL_OPENGL_ES2
364 glGenVertexArrays(1, &vertex_array_object);
365 #endif
366 ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
367
368 // Will project scissor/clipping rectangles into framebuffer space
369 ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
370 ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
371
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
377 // Upload vertex/index buffers
378 glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW);
379 glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW);
380
381 for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
382 {
383 const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
384 if (pcmd->UserCallback != NULL)
385 {
386 // User callback, registered via ImDrawList::AddCallback()
387 // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
388 if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
389 ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
390 else
391 pcmd->UserCallback(cmd_list, pcmd);
392 }
393 else
394 {
395 // Project scissor/clipping rectangles into framebuffer space
396 ImVec4 clip_rect;
397 clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
398 clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
399 clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
400 clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
401
402 if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
403 {
404 // Apply scissor/clipping rectangle
405 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));
406
407 // Bind texture, Draw
408 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
409 #if IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
410 if (g_GlVersion >= 320)
411 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);
412 else
413 #endif
414 glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)));
415 }
416 }
417 }
418 }
419
420 // Destroy the temporary VAO
421 #ifndef IMGUI_IMPL_OPENGL_ES2
422 glDeleteVertexArrays(1, &vertex_array_object);
423 #endif
424
425 // Restore modified GL state
426 glUseProgram(last_program);
427 glBindTexture(GL_TEXTURE_2D, last_texture);
428 #ifdef GL_SAMPLER_BINDING
429 glBindSampler(0, last_sampler);
430 #endif
431 glActiveTexture(last_active_texture);
432 #ifndef IMGUI_IMPL_OPENGL_ES2
433 glBindVertexArray(last_vertex_array_object);
434 #endif
435 glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
436 glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
437 glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
438 if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
439 if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
440 if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
441 if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
442 #ifdef GL_POLYGON_MODE
443 glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
444 #endif
445 glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
446 glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
447 }
448
ImGui_ImplOpenGL3_CreateFontsTexture()449 bool ImGui_ImplOpenGL3_CreateFontsTexture()
450 {
451 // Build texture atlas
452 ImGuiIO& io = ImGui::GetIO();
453 unsigned char* pixels;
454 int width, height;
455 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.
456
457 // Upload texture to graphics system
458 GLint last_texture;
459 glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
460 glGenTextures(1, &g_FontTexture);
461 glBindTexture(GL_TEXTURE_2D, g_FontTexture);
462 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
463 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
464 #ifdef GL_UNPACK_ROW_LENGTH
465 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
466 #endif
467 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
468
469 // Store our identifier
470 io.Fonts->TexID = (ImTextureID)(intptr_t)g_FontTexture;
471
472 // Restore state
473 glBindTexture(GL_TEXTURE_2D, last_texture);
474
475 return true;
476 }
477
ImGui_ImplOpenGL3_DestroyFontsTexture()478 void ImGui_ImplOpenGL3_DestroyFontsTexture()
479 {
480 if (g_FontTexture)
481 {
482 ImGuiIO& io = ImGui::GetIO();
483 glDeleteTextures(1, &g_FontTexture);
484 io.Fonts->TexID = 0;
485 g_FontTexture = 0;
486 }
487 }
488
489 // 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.
CheckShader(GLuint handle,const char * desc)490 static bool CheckShader(GLuint handle, const char* desc)
491 {
492 GLint status = 0, log_length = 0;
493 glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
494 glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
495 if ((GLboolean)status == GL_FALSE)
496 fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile %s!\n", desc);
497 if (log_length > 1)
498 {
499 ImVector<char> buf;
500 buf.resize((int)(log_length + 1));
501 glGetShaderInfoLog(handle, log_length, NULL, (GLchar*)buf.begin());
502 fprintf(stderr, "%s\n", buf.begin());
503 }
504 return (GLboolean)status == GL_TRUE;
505 }
506
507 // If you get an error please report on GitHub. You may try different GL context version or GLSL version.
CheckProgram(GLuint handle,const char * desc)508 static bool CheckProgram(GLuint handle, const char* desc)
509 {
510 GLint status = 0, log_length = 0;
511 glGetProgramiv(handle, GL_LINK_STATUS, &status);
512 glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
513 if ((GLboolean)status == GL_FALSE)
514 fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! (with GLSL '%s')\n", desc, g_GlslVersionString);
515 if (log_length > 1)
516 {
517 ImVector<char> buf;
518 buf.resize((int)(log_length + 1));
519 glGetProgramInfoLog(handle, log_length, NULL, (GLchar*)buf.begin());
520 fprintf(stderr, "%s\n", buf.begin());
521 }
522 return (GLboolean)status == GL_TRUE;
523 }
524
ImGui_ImplOpenGL3_CreateDeviceObjects()525 bool ImGui_ImplOpenGL3_CreateDeviceObjects()
526 {
527 // Backup GL state
528 GLint last_texture, last_array_buffer;
529 glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
530 glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
531 #ifndef IMGUI_IMPL_OPENGL_ES2
532 GLint last_vertex_array;
533 glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
534 #endif
535
536 // Parse GLSL version string
537 int glsl_version = 130;
538 sscanf(g_GlslVersionString, "#version %d", &glsl_version);
539
540 const GLchar* vertex_shader_glsl_120 =
541 "uniform mat4 ProjMtx;\n"
542 "attribute vec2 Position;\n"
543 "attribute vec2 UV;\n"
544 "attribute vec4 Color;\n"
545 "varying vec2 Frag_UV;\n"
546 "varying vec4 Frag_Color;\n"
547 "void main()\n"
548 "{\n"
549 " Frag_UV = UV;\n"
550 " Frag_Color = Color;\n"
551 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
552 "}\n";
553
554 const GLchar* vertex_shader_glsl_130 =
555 "uniform mat4 ProjMtx;\n"
556 "in vec2 Position;\n"
557 "in vec2 UV;\n"
558 "in vec4 Color;\n"
559 "out vec2 Frag_UV;\n"
560 "out vec4 Frag_Color;\n"
561 "void main()\n"
562 "{\n"
563 " Frag_UV = UV;\n"
564 " Frag_Color = Color;\n"
565 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
566 "}\n";
567
568 const GLchar* vertex_shader_glsl_300_es =
569 "precision mediump float;\n"
570 "layout (location = 0) in vec2 Position;\n"
571 "layout (location = 1) in vec2 UV;\n"
572 "layout (location = 2) in vec4 Color;\n"
573 "uniform mat4 ProjMtx;\n"
574 "out vec2 Frag_UV;\n"
575 "out vec4 Frag_Color;\n"
576 "void main()\n"
577 "{\n"
578 " Frag_UV = UV;\n"
579 " Frag_Color = Color;\n"
580 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
581 "}\n";
582
583 const GLchar* vertex_shader_glsl_410_core =
584 "layout (location = 0) in vec2 Position;\n"
585 "layout (location = 1) in vec2 UV;\n"
586 "layout (location = 2) in vec4 Color;\n"
587 "uniform mat4 ProjMtx;\n"
588 "out vec2 Frag_UV;\n"
589 "out vec4 Frag_Color;\n"
590 "void main()\n"
591 "{\n"
592 " Frag_UV = UV;\n"
593 " Frag_Color = Color;\n"
594 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
595 "}\n";
596
597 const GLchar* fragment_shader_glsl_120 =
598 "#ifdef GL_ES\n"
599 " precision mediump float;\n"
600 "#endif\n"
601 "uniform sampler2D Texture;\n"
602 "varying vec2 Frag_UV;\n"
603 "varying vec4 Frag_Color;\n"
604 "void main()\n"
605 "{\n"
606 " gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
607 "}\n";
608
609 const GLchar* fragment_shader_glsl_130 =
610 "uniform sampler2D Texture;\n"
611 "in vec2 Frag_UV;\n"
612 "in vec4 Frag_Color;\n"
613 "out vec4 Out_Color;\n"
614 "void main()\n"
615 "{\n"
616 " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
617 "}\n";
618
619 const GLchar* fragment_shader_glsl_300_es =
620 "precision mediump float;\n"
621 "uniform sampler2D Texture;\n"
622 "in vec2 Frag_UV;\n"
623 "in vec4 Frag_Color;\n"
624 "layout (location = 0) out vec4 Out_Color;\n"
625 "void main()\n"
626 "{\n"
627 " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
628 "}\n";
629
630 const GLchar* fragment_shader_glsl_410_core =
631 "in vec2 Frag_UV;\n"
632 "in vec4 Frag_Color;\n"
633 "uniform sampler2D Texture;\n"
634 "layout (location = 0) out vec4 Out_Color;\n"
635 "void main()\n"
636 "{\n"
637 " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
638 "}\n";
639
640 // Select shaders matching our GLSL versions
641 const GLchar* vertex_shader = NULL;
642 const GLchar* fragment_shader = NULL;
643 if (glsl_version < 130)
644 {
645 vertex_shader = vertex_shader_glsl_120;
646 fragment_shader = fragment_shader_glsl_120;
647 }
648 else if (glsl_version >= 410)
649 {
650 vertex_shader = vertex_shader_glsl_410_core;
651 fragment_shader = fragment_shader_glsl_410_core;
652 }
653 else if (glsl_version == 300)
654 {
655 vertex_shader = vertex_shader_glsl_300_es;
656 fragment_shader = fragment_shader_glsl_300_es;
657 }
658 else
659 {
660 vertex_shader = vertex_shader_glsl_130;
661 fragment_shader = fragment_shader_glsl_130;
662 }
663
664 // Create shaders
665 const GLchar* vertex_shader_with_version[2] = { g_GlslVersionString, vertex_shader };
666 g_VertHandle = glCreateShader(GL_VERTEX_SHADER);
667 glShaderSource(g_VertHandle, 2, vertex_shader_with_version, NULL);
668 glCompileShader(g_VertHandle);
669 CheckShader(g_VertHandle, "vertex shader");
670
671 const GLchar* fragment_shader_with_version[2] = { g_GlslVersionString, fragment_shader };
672 g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER);
673 glShaderSource(g_FragHandle, 2, fragment_shader_with_version, NULL);
674 glCompileShader(g_FragHandle);
675 CheckShader(g_FragHandle, "fragment shader");
676
677 g_ShaderHandle = glCreateProgram();
678 glAttachShader(g_ShaderHandle, g_VertHandle);
679 glAttachShader(g_ShaderHandle, g_FragHandle);
680 glLinkProgram(g_ShaderHandle);
681 CheckProgram(g_ShaderHandle, "shader program");
682
683 g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture");
684 g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx");
685 g_AttribLocationVtxPos = (GLuint)glGetAttribLocation(g_ShaderHandle, "Position");
686 g_AttribLocationVtxUV = (GLuint)glGetAttribLocation(g_ShaderHandle, "UV");
687 g_AttribLocationVtxColor = (GLuint)glGetAttribLocation(g_ShaderHandle, "Color");
688
689 // Create buffers
690 glGenBuffers(1, &g_VboHandle);
691 glGenBuffers(1, &g_ElementsHandle);
692
693 ImGui_ImplOpenGL3_CreateFontsTexture();
694
695 // Restore modified GL state
696 glBindTexture(GL_TEXTURE_2D, last_texture);
697 glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
698 #ifndef IMGUI_IMPL_OPENGL_ES2
699 glBindVertexArray(last_vertex_array);
700 #endif
701
702 return true;
703 }
704
ImGui_ImplOpenGL3_DestroyDeviceObjects()705 void ImGui_ImplOpenGL3_DestroyDeviceObjects()
706 {
707 if (g_VboHandle) { glDeleteBuffers(1, &g_VboHandle); g_VboHandle = 0; }
708 if (g_ElementsHandle) { glDeleteBuffers(1, &g_ElementsHandle); g_ElementsHandle = 0; }
709 if (g_ShaderHandle && g_VertHandle) { glDetachShader(g_ShaderHandle, g_VertHandle); }
710 if (g_ShaderHandle && g_FragHandle) { glDetachShader(g_ShaderHandle, g_FragHandle); }
711 if (g_VertHandle) { glDeleteShader(g_VertHandle); g_VertHandle = 0; }
712 if (g_FragHandle) { glDeleteShader(g_FragHandle); g_FragHandle = 0; }
713 if (g_ShaderHandle) { glDeleteProgram(g_ShaderHandle); g_ShaderHandle = 0; }
714
715 ImGui_ImplOpenGL3_DestroyFontsTexture();
716 }
717
718 //--------------------------------------------------------------------------------------------------------
719 // MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
720 // This is an _advanced_ and _optional_ feature, allowing the back-end to create and handle multiple viewports simultaneously.
721 // 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..
722 //--------------------------------------------------------------------------------------------------------
723
ImGui_ImplOpenGL3_RenderWindow(ImGuiViewport * viewport,void *)724 static void ImGui_ImplOpenGL3_RenderWindow(ImGuiViewport* viewport, void*)
725 {
726 if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
727 {
728 ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
729 glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
730 glClear(GL_COLOR_BUFFER_BIT);
731 }
732 ImGui_ImplOpenGL3_RenderDrawData(viewport->DrawData);
733 }
734
ImGui_ImplOpenGL3_InitPlatformInterface()735 static void ImGui_ImplOpenGL3_InitPlatformInterface()
736 {
737 ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
738 platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
739 }
740
ImGui_ImplOpenGL3_ShutdownPlatformInterface()741 static void ImGui_ImplOpenGL3_ShutdownPlatformInterface()
742 {
743 ImGui::DestroyPlatformWindows();
744 }
745