source: opengl-game/IMGUI/imgui_impl_opengl3.cpp@ ca188cc

Last change on this file since ca188cc was e66fd66, checked in by Dmitry Portnoy <dportnoy@…>, 4 years ago

In OpenGLReference, change all enums to enum classes and update IMGUI to the latest version
  • Property mode set to 100644
File size: 31.9 KB
RevLine 
[e66fd66]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: Desktop GL only: Support for large meshes (64k+ vertices) with 16-bit indices.
9
10// You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
11// If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
12// https://github.com/ocornut/imgui
13
14// CHANGELOG
15// (minor and older changes stripped away, please see git history for details)
16// 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.
17// 2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
18// 2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
19// 2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by inverting projection matrix.
20// 2020-04-12: OpenGL: Fixed context version check mistakenly testing for 4.0+ instead of 3.2+ to enable ImGuiBackendFlags_RendererHasVtxOffset.
21// 2020-03-24: OpenGL: Added support for glbinding 2.x OpenGL loader.
22// 2020-01-07: OpenGL: Added support for glbinding 3.x OpenGL loader.
23// 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.
24// 2019-09-22: OpenGL: Detect default GL loader using __has_include compiler facility.
25// 2019-09-16: OpenGL: Tweak initialization code to allow application calling ImGui_ImplOpenGL3_CreateFontsTexture() before the first NewFrame() call.
26// 2019-05-29: OpenGL: Desktop GL only: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
27// 2019-04-30: OpenGL: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
28// 2019-03-29: OpenGL: Not calling glBindBuffer more than necessary in the render loop.
29// 2019-03-15: OpenGL: Added a GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early.
30// 2019-03-03: OpenGL: Fix support for ES 2.0 (WebGL 1.0).
31// 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.
32// 2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
33// 2019-02-01: OpenGL: Using GLSL 410 shaders for any version over 410 (e.g. 430, 450).
34// 2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
35// 2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT) / GL_CLIP_ORIGIN.
36// 2018-08-29: OpenGL: Added support for more OpenGL loaders: glew and glad, with comments indicative that any loader can be used.
37// 2018-08-09: OpenGL: Default to OpenGL ES 3 on iOS and Android. GLSL version default to "#version 300 ES".
38// 2018-07-30: OpenGL: Support for GLSL 300 ES and 410 core. Fixes for Emscripten compilation.
39// 2018-07-10: OpenGL: Support for more GLSL versions (based on the GLSL version string). Added error output when shaders fail to compile/link.
40// 2018-06-08: Misc: Extracted imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3 examples.
41// 2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
42// 2018-05-25: OpenGL: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
43// 2018-05-14: OpenGL: Making the call to glBindSampler() optional so 3.2 context won't fail if the function is a NULL pointer.
44// 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".
45// 2018-02-23: OpenGL: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context.
46// 2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplSdlGL3_RenderDrawData() in the .h file so you can call it yourself.
47// 2018-01-07: OpenGL: Changed GLSL shader version from 330 to 150.
48// 2017-09-01: OpenGL: Save and restore current bound sampler. Save and restore current polygon mode.
49// 2017-05-01: OpenGL: Fixed save and restore of current blend func state.
50// 2017-05-01: OpenGL: Fixed save and restore of current GL_ACTIVE_TEXTURE.
51// 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
52// 2016-07-29: OpenGL: Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes it. (#752)
53
54//----------------------------------------
55// OpenGL GLSL GLSL
56// version version string
57//----------------------------------------
58// 2.0 110 "#version 110"
59// 2.1 120 "#version 120"
60// 3.0 130 "#version 130"
61// 3.1 140 "#version 140"
62// 3.2 150 "#version 150"
63// 3.3 330 "#version 330 core"
64// 4.0 400 "#version 400 core"
65// 4.1 410 "#version 410 core"
66// 4.2 420 "#version 410 core"
67// 4.3 430 "#version 430 core"
68// ES 2.0 100 "#version 100" = WebGL 1.0
69// ES 3.0 300 "#version 300 es" = WebGL 2.0
70//----------------------------------------
71
72#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
73#define _CRT_SECURE_NO_WARNINGS
74#endif
75
76#include "imgui.h"
77#include "imgui_impl_opengl3.h"
78#include <stdio.h>
79#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
80#include <stddef.h> // intptr_t
81#else
82#include <stdint.h> // intptr_t
83#endif
84
85// GL includes
86#if defined(IMGUI_IMPL_OPENGL_ES2)
87#include <GLES2/gl2.h>
88#elif defined(IMGUI_IMPL_OPENGL_ES3)
89#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
90#include <OpenGLES/ES3/gl.h> // Use GL ES 3
91#else
92#include <GLES3/gl3.h> // Use GL ES 3
93#endif
94#else
95// About Desktop OpenGL function loaders:
96// Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
97// Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad).
98// You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.
99#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
100#include <GL/gl3w.h> // Needs to be initialized with gl3wInit() in user's code
101#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
102#include <GL/glew.h> // Needs to be initialized with glewInit() in user's code.
103#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
104#include <glad/glad.h> // Needs to be initialized with gladLoadGL() in user's code.
105#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
106#include <glad/gl.h> // Needs to be initialized with gladLoadGL(...) or gladLoaderLoadGL() in user's code.
107#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
108#ifndef GLFW_INCLUDE_NONE
109#define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
110#endif
111#include <glbinding/Binding.h> // Needs to be initialized with glbinding::Binding::initialize() in user's code.
112#include <glbinding/gl/gl.h>
113using namespace gl;
114#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
115#ifndef GLFW_INCLUDE_NONE
116#define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
117#endif
118#include <glbinding/glbinding.h>// Needs to be initialized with glbinding::initialize() in user's code.
119#include <glbinding/gl/gl.h>
120using namespace gl;
121#else
122#include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
123#endif
124#endif
125
126// Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't have.
127#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_2)
128#define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
129#endif
130
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
136// OpenGL Data
137static GLuint g_GlVersion = 0; // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
138static char g_GlslVersionString[32] = ""; // Specified by user or detected based on compile time GL settings.
139static GLuint g_FontTexture = 0;
140static GLuint g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
141static GLint g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; // Uniforms location
142static GLuint g_AttribLocationVtxPos = 0, g_AttribLocationVtxUV = 0, g_AttribLocationVtxColor = 0; // Vertex attributes location
143static unsigned int g_VboHandle = 0, g_ElementsHandle = 0;
144
145// Functions
146bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
147{
148 // Query for GL version (e.g. 320 for GL 3.2)
149#if !defined(IMGUI_IMPL_OPENGL_ES2)
150 GLint major, minor;
151 glGetIntegerv(GL_MAJOR_VERSION, &major);
152 glGetIntegerv(GL_MINOR_VERSION, &minor);
153 g_GlVersion = (GLuint)(major * 100 + minor * 10);
154#else
155 g_GlVersion = 200; // GLES 2
156#endif
157
158 // Setup back-end capabilities flags
159 ImGuiIO& io = ImGui::GetIO();
160 io.BackendRendererName = "imgui_impl_opengl3";
161#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
162 if (g_GlVersion >= 320)
163 io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
164#endif
165
166 // Store GLSL version string so we can refer to it later in case we recreate shaders.
167 // Note: GLSL version is NOT the same as GL version. Leave this to NULL if unsure.
168#if defined(IMGUI_IMPL_OPENGL_ES2)
169 if (glsl_version == NULL)
170 glsl_version = "#version 100";
171#elif defined(IMGUI_IMPL_OPENGL_ES3)
172 if (glsl_version == NULL)
173 glsl_version = "#version 300 es";
174#elif defined(__APPLE__)
175 if (glsl_version == NULL)
176 glsl_version = "#version 150";
177#else
178 if (glsl_version == NULL)
179 glsl_version = "#version 130";
180#endif
181 IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(g_GlslVersionString));
182 strcpy(g_GlslVersionString, glsl_version);
183 strcat(g_GlslVersionString, "\n");
184
185 // Debugging construct to make it easily visible in the IDE and debugger which GL loader has been selected.
186 // The code actually never uses the 'gl_loader' variable! It is only here so you can read it!
187 // If auto-detection fails or doesn't select the same GL loader file as used by your application,
188 // you are likely to get a crash below.
189 // You can explicitly select a loader by using '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
190 const char* gl_loader = "Unknown";
191 IM_UNUSED(gl_loader);
192#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
193 gl_loader = "GL3W";
194#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
195 gl_loader = "GLEW";
196#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
197 gl_loader = "GLAD";
198#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
199 gl_loader = "GLAD2";
200#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
201 gl_loader = "glbinding2";
202#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
203 gl_loader = "glbinding3";
204#elif defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
205 gl_loader = "custom";
206#else
207 gl_loader = "none";
208#endif
209
210 // Make an arbitrary GL call (we don't actually need the result)
211 // IF YOU GET A CRASH HERE: it probably means that you haven't initialized the OpenGL function loader used by this code.
212 // Desktop OpenGL 3/4 need a function loader. See the IMGUI_IMPL_OPENGL_LOADER_xxx explanation above.
213 GLint current_texture;
214 glGetIntegerv(GL_TEXTURE_BINDING_2D, &current_texture);
215
216 return true;
217}
218
219void ImGui_ImplOpenGL3_Shutdown()
220{
221 ImGui_ImplOpenGL3_DestroyDeviceObjects();
222}
223
224void ImGui_ImplOpenGL3_NewFrame()
225{
226 if (!g_ShaderHandle)
227 ImGui_ImplOpenGL3_CreateDeviceObjects();
228}
229
230static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height, GLuint vertex_array_object)
231{
232 // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
233 glEnable(GL_BLEND);
234 glBlendEquation(GL_FUNC_ADD);
235 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
236 glDisable(GL_CULL_FACE);
237 glDisable(GL_DEPTH_TEST);
238 glEnable(GL_SCISSOR_TEST);
239#ifdef GL_POLYGON_MODE
240 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
241#endif
242
243 // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT)
244 bool clip_origin_lower_left = true;
245#if defined(GL_CLIP_ORIGIN) && !defined(__APPLE__)
246 GLenum current_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)&current_clip_origin);
247 if (current_clip_origin == GL_UPPER_LEFT)
248 clip_origin_lower_left = false;
249#endif
250
251 // Setup viewport, orthographic projection matrix
252 // 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.
253 glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height);
254 float L = draw_data->DisplayPos.x;
255 float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
256 float T = draw_data->DisplayPos.y;
257 float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
258 if (!clip_origin_lower_left) { float tmp = T; T = B; B = tmp; } // Swap top and bottom if origin is upper left
259 const float ortho_projection[4][4] =
260 {
261 { 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
262 { 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
263 { 0.0f, 0.0f, -1.0f, 0.0f },
264 { (R+L)/(L-R), (T+B)/(B-T), 0.0f, 1.0f },
265 };
266 glUseProgram(g_ShaderHandle);
267 glUniform1i(g_AttribLocationTex, 0);
268 glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
269
270#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
271 if (g_GlVersion >= 330)
272 glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
273#endif
274
275 (void)vertex_array_object;
276#ifndef IMGUI_IMPL_OPENGL_ES2
277 glBindVertexArray(vertex_array_object);
278#endif
279
280 // Bind vertex/index buffers and setup attributes for ImDrawVert
281 glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
282 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle);
283 glEnableVertexAttribArray(g_AttribLocationVtxPos);
284 glEnableVertexAttribArray(g_AttribLocationVtxUV);
285 glEnableVertexAttribArray(g_AttribLocationVtxColor);
286 glVertexAttribPointer(g_AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos));
287 glVertexAttribPointer(g_AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
288 glVertexAttribPointer(g_AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
289}
290
291// OpenGL3 Render function.
292// (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
293// 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.
294void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
295{
296 // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
297 int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
298 int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
299 if (fb_width <= 0 || fb_height <= 0)
300 return;
301
302 // Backup GL state
303 GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
304 glActiveTexture(GL_TEXTURE0);
305 GLuint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&last_program);
306 GLuint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint*)&last_texture);
307#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
308 GLuint last_sampler; if (g_GlVersion >= 330) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
309#endif
310 GLuint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint*)&last_array_buffer);
311#ifndef IMGUI_IMPL_OPENGL_ES2
312 GLuint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, (GLint*)&last_vertex_array_object);
313#endif
314#ifdef GL_POLYGON_MODE
315 GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
316#endif
317 GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
318 GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
319 GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb);
320 GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb);
321 GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha);
322 GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha);
323 GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb);
324 GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha);
325 GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
326 GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
327 GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
328 GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
329
330 // Setup desired GL state
331 // Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
332 // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
333 GLuint vertex_array_object = 0;
334#ifndef IMGUI_IMPL_OPENGL_ES2
335 glGenVertexArrays(1, &vertex_array_object);
336#endif
337 ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
338
339 // Will project scissor/clipping rectangles into framebuffer space
340 ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
341 ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
342
343 // Render command lists
344 for (int n = 0; n < draw_data->CmdListsCount; n++)
345 {
346 const ImDrawList* cmd_list = draw_data->CmdLists[n];
347
348 // Upload vertex/index buffers
349 glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW);
350 glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW);
351
352 for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
353 {
354 const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
355 if (pcmd->UserCallback != NULL)
356 {
357 // User callback, registered via ImDrawList::AddCallback()
358 // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
359 if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
360 ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
361 else
362 pcmd->UserCallback(cmd_list, pcmd);
363 }
364 else
365 {
366 // Project scissor/clipping rectangles into framebuffer space
367 ImVec4 clip_rect;
368 clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
369 clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
370 clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
371 clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
372
373 if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
374 {
375 // Apply scissor/clipping rectangle
376 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));
377
378 // Bind texture, Draw
379 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
380#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
381 if (g_GlVersion >= 320)
382 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);
383 else
384#endif
385 glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)));
386 }
387 }
388 }
389 }
390
391 // Destroy the temporary VAO
392#ifndef IMGUI_IMPL_OPENGL_ES2
393 glDeleteVertexArrays(1, &vertex_array_object);
394#endif
395
396 // Restore modified GL state
397 glUseProgram(last_program);
398 glBindTexture(GL_TEXTURE_2D, last_texture);
399#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
400 if (g_GlVersion >= 330)
401 glBindSampler(0, last_sampler);
402#endif
403 glActiveTexture(last_active_texture);
404#ifndef IMGUI_IMPL_OPENGL_ES2
405 glBindVertexArray(last_vertex_array_object);
406#endif
407 glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
408 glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
409 glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
410 if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
411 if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
412 if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
413 if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
414#ifdef GL_POLYGON_MODE
415 glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
416#endif
417 glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
418 glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
419}
420
421bool ImGui_ImplOpenGL3_CreateFontsTexture()
422{
423 // Build texture atlas
424 ImGuiIO& io = ImGui::GetIO();
425 unsigned char* pixels;
426 int width, height;
427 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.
428
429 // Upload texture to graphics system
430 GLint last_texture;
431 glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
432 glGenTextures(1, &g_FontTexture);
433 glBindTexture(GL_TEXTURE_2D, g_FontTexture);
434 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
435 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
436#ifdef GL_UNPACK_ROW_LENGTH
437 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
438#endif
439 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
440
441 // Store our identifier
442 io.Fonts->TexID = (ImTextureID)(intptr_t)g_FontTexture;
443
444 // Restore state
445 glBindTexture(GL_TEXTURE_2D, last_texture);
446
447 return true;
448}
449
450void ImGui_ImplOpenGL3_DestroyFontsTexture()
451{
452 if (g_FontTexture)
453 {
454 ImGuiIO& io = ImGui::GetIO();
455 glDeleteTextures(1, &g_FontTexture);
456 io.Fonts->TexID = 0;
457 g_FontTexture = 0;
458 }
459}
460
461// 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.
462static bool CheckShader(GLuint handle, const char* desc)
463{
464 GLint status = 0, log_length = 0;
465 glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
466 glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
467 if ((GLboolean)status == GL_FALSE)
468 fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile %s!\n", desc);
469 if (log_length > 1)
470 {
471 ImVector<char> buf;
472 buf.resize((int)(log_length + 1));
473 glGetShaderInfoLog(handle, log_length, NULL, (GLchar*)buf.begin());
474 fprintf(stderr, "%s\n", buf.begin());
475 }
476 return (GLboolean)status == GL_TRUE;
477}
478
479// If you get an error please report on GitHub. You may try different GL context version or GLSL version.
480static bool CheckProgram(GLuint handle, const char* desc)
481{
482 GLint status = 0, log_length = 0;
483 glGetProgramiv(handle, GL_LINK_STATUS, &status);
484 glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
485 if ((GLboolean)status == GL_FALSE)
486 fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! (with GLSL '%s')\n", desc, g_GlslVersionString);
487 if (log_length > 1)
488 {
489 ImVector<char> buf;
490 buf.resize((int)(log_length + 1));
491 glGetProgramInfoLog(handle, log_length, NULL, (GLchar*)buf.begin());
492 fprintf(stderr, "%s\n", buf.begin());
493 }
494 return (GLboolean)status == GL_TRUE;
495}
496
497bool ImGui_ImplOpenGL3_CreateDeviceObjects()
498{
499 // Backup GL state
500 GLint last_texture, last_array_buffer;
501 glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
502 glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
503#ifndef IMGUI_IMPL_OPENGL_ES2
504 GLint last_vertex_array;
505 glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
506#endif
507
508 // Parse GLSL version string
509 int glsl_version = 130;
510 sscanf(g_GlslVersionString, "#version %d", &glsl_version);
511
512 const GLchar* vertex_shader_glsl_120 =
513 "uniform mat4 ProjMtx;\n"
514 "attribute vec2 Position;\n"
515 "attribute vec2 UV;\n"
516 "attribute vec4 Color;\n"
517 "varying vec2 Frag_UV;\n"
518 "varying vec4 Frag_Color;\n"
519 "void main()\n"
520 "{\n"
521 " Frag_UV = UV;\n"
522 " Frag_Color = Color;\n"
523 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
524 "}\n";
525
526 const GLchar* vertex_shader_glsl_130 =
527 "uniform mat4 ProjMtx;\n"
528 "in vec2 Position;\n"
529 "in vec2 UV;\n"
530 "in vec4 Color;\n"
531 "out vec2 Frag_UV;\n"
532 "out vec4 Frag_Color;\n"
533 "void main()\n"
534 "{\n"
535 " Frag_UV = UV;\n"
536 " Frag_Color = Color;\n"
537 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
538 "}\n";
539
540 const GLchar* vertex_shader_glsl_300_es =
541 "precision mediump float;\n"
542 "layout (location = 0) in vec2 Position;\n"
543 "layout (location = 1) in vec2 UV;\n"
544 "layout (location = 2) in vec4 Color;\n"
545 "uniform mat4 ProjMtx;\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
555 const GLchar* vertex_shader_glsl_410_core =
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
569 const GLchar* fragment_shader_glsl_120 =
570 "#ifdef GL_ES\n"
571 " precision mediump float;\n"
572 "#endif\n"
573 "uniform sampler2D Texture;\n"
574 "varying vec2 Frag_UV;\n"
575 "varying vec4 Frag_Color;\n"
576 "void main()\n"
577 "{\n"
578 " gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
579 "}\n";
580
581 const GLchar* fragment_shader_glsl_130 =
582 "uniform sampler2D Texture;\n"
583 "in vec2 Frag_UV;\n"
584 "in vec4 Frag_Color;\n"
585 "out vec4 Out_Color;\n"
586 "void main()\n"
587 "{\n"
588 " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
589 "}\n";
590
591 const GLchar* fragment_shader_glsl_300_es =
592 "precision mediump float;\n"
593 "uniform sampler2D Texture;\n"
594 "in vec2 Frag_UV;\n"
595 "in vec4 Frag_Color;\n"
596 "layout (location = 0) 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
602 const GLchar* fragment_shader_glsl_410_core =
603 "in vec2 Frag_UV;\n"
604 "in vec4 Frag_Color;\n"
605 "uniform sampler2D Texture;\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
612 // Select shaders matching our GLSL versions
613 const GLchar* vertex_shader = NULL;
614 const GLchar* fragment_shader = NULL;
615 if (glsl_version < 130)
616 {
617 vertex_shader = vertex_shader_glsl_120;
618 fragment_shader = fragment_shader_glsl_120;
619 }
620 else if (glsl_version >= 410)
621 {
622 vertex_shader = vertex_shader_glsl_410_core;
623 fragment_shader = fragment_shader_glsl_410_core;
624 }
625 else if (glsl_version == 300)
626 {
627 vertex_shader = vertex_shader_glsl_300_es;
628 fragment_shader = fragment_shader_glsl_300_es;
629 }
630 else
631 {
632 vertex_shader = vertex_shader_glsl_130;
633 fragment_shader = fragment_shader_glsl_130;
634 }
635
636 // Create shaders
637 const GLchar* vertex_shader_with_version[2] = { g_GlslVersionString, vertex_shader };
638 g_VertHandle = glCreateShader(GL_VERTEX_SHADER);
639 glShaderSource(g_VertHandle, 2, vertex_shader_with_version, NULL);
640 glCompileShader(g_VertHandle);
641 CheckShader(g_VertHandle, "vertex shader");
642
643 const GLchar* fragment_shader_with_version[2] = { g_GlslVersionString, fragment_shader };
644 g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER);
645 glShaderSource(g_FragHandle, 2, fragment_shader_with_version, NULL);
646 glCompileShader(g_FragHandle);
647 CheckShader(g_FragHandle, "fragment shader");
648
649 g_ShaderHandle = glCreateProgram();
650 glAttachShader(g_ShaderHandle, g_VertHandle);
651 glAttachShader(g_ShaderHandle, g_FragHandle);
652 glLinkProgram(g_ShaderHandle);
653 CheckProgram(g_ShaderHandle, "shader program");
654
655 g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture");
656 g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx");
657 g_AttribLocationVtxPos = (GLuint)glGetAttribLocation(g_ShaderHandle, "Position");
658 g_AttribLocationVtxUV = (GLuint)glGetAttribLocation(g_ShaderHandle, "UV");
659 g_AttribLocationVtxColor = (GLuint)glGetAttribLocation(g_ShaderHandle, "Color");
660
661 // Create buffers
662 glGenBuffers(1, &g_VboHandle);
663 glGenBuffers(1, &g_ElementsHandle);
664
665 ImGui_ImplOpenGL3_CreateFontsTexture();
666
667 // Restore modified GL state
668 glBindTexture(GL_TEXTURE_2D, last_texture);
669 glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
670#ifndef IMGUI_IMPL_OPENGL_ES2
671 glBindVertexArray(last_vertex_array);
672#endif
673
674 return true;
675}
676
677void ImGui_ImplOpenGL3_DestroyDeviceObjects()
678{
679 if (g_VboHandle) { glDeleteBuffers(1, &g_VboHandle); g_VboHandle = 0; }
680 if (g_ElementsHandle) { glDeleteBuffers(1, &g_ElementsHandle); g_ElementsHandle = 0; }
681 if (g_ShaderHandle && g_VertHandle) { glDetachShader(g_ShaderHandle, g_VertHandle); }
682 if (g_ShaderHandle && g_FragHandle) { glDetachShader(g_ShaderHandle, g_FragHandle); }
683 if (g_VertHandle) { glDeleteShader(g_VertHandle); g_VertHandle = 0; }
684 if (g_FragHandle) { glDeleteShader(g_FragHandle); g_FragHandle = 0; }
685 if (g_ShaderHandle) { glDeleteProgram(g_ShaderHandle); g_ShaderHandle = 0; }
686
687 ImGui_ImplOpenGL3_DestroyFontsTexture();
688}
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