1 // dear imgui: Renderer for OpenGL3 / OpenGL ES2 / OpenGL ES3 (modern OpenGL with shaders / programmatic pipeline)
2 // This needs to be used along with a Platform Binding (e.g. GLFW, SDL, Win32, custom..)
3 // (Note: We are using GL3W as a helper library to access OpenGL functions since there is no standard header to access modern OpenGL functions easily. Alternatives are GLEW, Glad, etc..)
4
5 // Implemented features:
6 // [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID in imgui.cpp.
7
8 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
9 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
10 // https://github.com/ocornut/imgui
11
12 // CHANGELOG
13 // (minor and older changes stripped away, please see git history for details)
14 // 2019-02-01: OpenGL: Using GLSL 410 shaders for any version over 410 (e.g. 430, 450).
15 // 2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
16 // 2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT).
17 // 2018-08-29: OpenGL: Added support for more OpenGL loaders: glew and glad, with comments indicative that any loader can be used.
18 // 2018-08-09: OpenGL: Default to OpenGL ES 3 on iOS and Android. GLSL version default to "#version 300 ES".
19 // 2018-07-30: OpenGL: Support for GLSL 300 ES and 410 core. Fixes for Emscripten compilation.
20 // 2018-07-10: OpenGL: Support for more GLSL versions (based on the GLSL version string). Added error output when shaders fail to compile/link.
21 // 2018-06-08: Misc: Extracted imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3 examples.
22 // 2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
23 // 2018-05-25: OpenGL: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
24 // 2018-05-14: OpenGL: Making the call to glBindSampler() optional so 3.2 context won't fail if the function is a NULL pointer.
25 // 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".
26 // 2018-02-23: OpenGL: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context.
27 // 2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplSdlGL3_RenderDrawData() in the .h file so you can call it yourself.
28 // 2018-01-07: OpenGL: Changed GLSL shader version from 330 to 150.
29 // 2017-09-01: OpenGL: Save and restore current bound sampler. Save and restore current polygon mode.
30 // 2017-05-01: OpenGL: Fixed save and restore of current blend func state.
31 // 2017-05-01: OpenGL: Fixed save and restore of current GL_ACTIVE_TEXTURE.
32 // 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
33 // 2016-07-29: OpenGL: Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes it. (#752)
34
35 //----------------------------------------
36 // OpenGL GLSL GLSL
37 // version version string
38 //----------------------------------------
39 // 2.0 110 "#version 110"
40 // 2.1 120
41 // 3.0 130
42 // 3.1 140
43 // 3.2 150 "#version 150"
44 // 3.3 330
45 // 4.0 400
46 // 4.1 410 "#version 410 core"
47 // 4.2 420
48 // 4.3 430
49 // ES 2.0 100 "#version 100"
50 // ES 3.0 300 "#version 300 es"
51 //----------------------------------------
52
53 #if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
54 #define _CRT_SECURE_NO_WARNINGS
55 #endif
56
57 // MOD_ERIN
58 #include "imgui/imgui.h"
59 #include "imgui_impl_opengl3.h"
60 #include <stdio.h>
61 #if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
62 #include <stddef.h> // intptr_t
63 #else
64 #include <stdint.h> // intptr_t
65 #endif
66 #if defined(__APPLE__)
67 #include "TargetConditionals.h"
68 #endif
69
70 // iOS, Android and Emscripten can use GL ES 3
71 // Call ImGui_ImplOpenGL3_Init() with "#version 300 es"
72 #if (defined(__APPLE__) && TARGET_OS_IOS) || (defined(__ANDROID__)) || (defined(__EMSCRIPTEN__))
73 #define USE_GL_ES3
74 #endif
75
76 #ifdef USE_GL_ES3
77 // OpenGL ES 3
78 #include <GLES3/gl3.h> // Use GL ES 3
79 #else
80 // Regular OpenGL
81 // About OpenGL function loaders: modern OpenGL doesn't have a standard header file and requires individual function pointers to be loaded manually.
82 // Helper libraries are often used for this purpose! Here we are supporting a few common ones: gl3w, glew, glad.
83 // You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.
84 #if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
85 #include <GL/gl3w.h>
86 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
87 #include <GL/glew.h>
88 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
89 // MOD_ERIN
90 #include "glad/gl.h"
91 #else
92 #include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
93 #endif
94 #endif
95
96 // OpenGL Data
97 static char g_GlslVersionString[32] = "";
98 static GLuint g_FontTexture = 0;
99 static GLuint g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
100 static int g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0;
101 static int g_AttribLocationPosition = 0, g_AttribLocationUV = 0, g_AttribLocationColor = 0;
102 static unsigned int g_VboHandle = 0, g_ElementsHandle = 0;
103
104 // Functions
ImGui_ImplOpenGL3_Init(const char * glsl_version)105 bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
106 {
107 ImGuiIO& io = ImGui::GetIO();
108 io.BackendRendererName = "imgui_impl_opengl3";
109
110 // Store GLSL version string so we can refer to it later in case we recreate shaders. Note: GLSL version is NOT the same as GL version. Leave this to NULL if unsure.
111 #ifdef USE_GL_ES3
112 if (glsl_version == NULL)
113 glsl_version = "#version 300 es";
114 #else
115 if (glsl_version == NULL)
116 glsl_version = "#version 130";
117 #endif
118 IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(g_GlslVersionString));
119 strcpy(g_GlslVersionString, glsl_version);
120 strcat(g_GlslVersionString, "\n");
121
122 return true;
123 }
124
ImGui_ImplOpenGL3_Shutdown()125 void ImGui_ImplOpenGL3_Shutdown()
126 {
127 ImGui_ImplOpenGL3_DestroyDeviceObjects();
128 }
129
ImGui_ImplOpenGL3_NewFrame()130 void ImGui_ImplOpenGL3_NewFrame()
131 {
132 if (!g_FontTexture)
133 ImGui_ImplOpenGL3_CreateDeviceObjects();
134 }
135
136 // OpenGL3 Render function.
137 // (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
138 // 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)139 void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
140 {
141 // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
142 ImGuiIO& io = ImGui::GetIO();
143 int fb_width = (int)(draw_data->DisplaySize.x * io.DisplayFramebufferScale.x);
144 int fb_height = (int)(draw_data->DisplaySize.y * io.DisplayFramebufferScale.y);
145 if (fb_width <= 0 || fb_height <= 0)
146 return;
147 draw_data->ScaleClipRects(io.DisplayFramebufferScale);
148
149 // Backup GL state
150 GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
151 glActiveTexture(GL_TEXTURE0);
152 GLint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
153 GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
154 #ifdef GL_SAMPLER_BINDING
155 GLint last_sampler; glGetIntegerv(GL_SAMPLER_BINDING, &last_sampler);
156 #endif
157 GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
158 GLint last_vertex_array; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
159 #ifdef GL_POLYGON_MODE
160 GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
161 #endif
162 GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
163 GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
164 GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb);
165 GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb);
166 GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha);
167 GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha);
168 GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb);
169 GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha);
170 GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
171 GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
172 GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
173 GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
174 bool clip_origin_lower_left = true;
175 #ifdef GL_CLIP_ORIGIN
176 GLenum last_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)&last_clip_origin); // Support for GL 4.5's glClipControl(GL_UPPER_LEFT)
177 if (last_clip_origin == GL_UPPER_LEFT)
178 clip_origin_lower_left = false;
179 #endif
180
181 // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
182 glEnable(GL_BLEND);
183 glBlendEquation(GL_FUNC_ADD);
184 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
185 glDisable(GL_CULL_FACE);
186 glDisable(GL_DEPTH_TEST);
187 glEnable(GL_SCISSOR_TEST);
188 #ifdef GL_POLYGON_MODE
189 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
190 #endif
191
192 // Setup viewport, orthographic projection matrix
193 // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayMin is typically (0,0) for single viewport apps.
194 glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height);
195 float L = draw_data->DisplayPos.x;
196 float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
197 float T = draw_data->DisplayPos.y;
198 float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
199 const float ortho_projection[4][4] =
200 {
201 { 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
202 { 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
203 { 0.0f, 0.0f, -1.0f, 0.0f },
204 { (R+L)/(L-R), (T+B)/(B-T), 0.0f, 1.0f },
205 };
206 glUseProgram(g_ShaderHandle);
207 glUniform1i(g_AttribLocationTex, 0);
208 glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
209 #ifdef GL_SAMPLER_BINDING
210 glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
211 #endif
212 // Recreate the VAO every time
213 // (This is to easily allow multiple GL contexts. VAO are not shared among GL contexts, and we don't track creation/deletion of windows so we don't have an obvious key to use to cache them.)
214 GLuint vao_handle = 0;
215 glGenVertexArrays(1, &vao_handle);
216 glBindVertexArray(vao_handle);
217 glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
218 glEnableVertexAttribArray(g_AttribLocationPosition);
219 glEnableVertexAttribArray(g_AttribLocationUV);
220 glEnableVertexAttribArray(g_AttribLocationColor);
221 glVertexAttribPointer(g_AttribLocationPosition, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos));
222 glVertexAttribPointer(g_AttribLocationUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
223 glVertexAttribPointer(g_AttribLocationColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
224
225 // Draw
226 ImVec2 pos = draw_data->DisplayPos;
227 for (int n = 0; n < draw_data->CmdListsCount; n++)
228 {
229 const ImDrawList* cmd_list = draw_data->CmdLists[n];
230 const ImDrawIdx* idx_buffer_offset = 0;
231
232 glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
233 glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW);
234
235 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle);
236 glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW);
237
238 for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
239 {
240 const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
241 if (pcmd->UserCallback)
242 {
243 // User callback (registered via ImDrawList::AddCallback)
244 pcmd->UserCallback(cmd_list, pcmd);
245 }
246 else
247 {
248 ImVec4 clip_rect = ImVec4(pcmd->ClipRect.x - pos.x, pcmd->ClipRect.y - pos.y, pcmd->ClipRect.z - pos.x, pcmd->ClipRect.w - pos.y);
249 if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
250 {
251 // Apply scissor/clipping rectangle
252 if (clip_origin_lower_left)
253 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));
254 else
255 glScissor((int)clip_rect.x, (int)clip_rect.y, (int)clip_rect.z, (int)clip_rect.w); // Support for GL 4.5's glClipControl(GL_UPPER_LEFT)
256
257 // Bind texture, Draw
258 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
259 glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset);
260 }
261 }
262 idx_buffer_offset += pcmd->ElemCount;
263 }
264 }
265 glDeleteVertexArrays(1, &vao_handle);
266
267 // Restore modified GL state
268 glUseProgram(last_program);
269 glBindTexture(GL_TEXTURE_2D, last_texture);
270 #ifdef GL_SAMPLER_BINDING
271 glBindSampler(0, last_sampler);
272 #endif
273 glActiveTexture(last_active_texture);
274 glBindVertexArray(last_vertex_array);
275 glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
276 glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
277 glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
278 if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
279 if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
280 if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
281 if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
282 #ifdef GL_POLYGON_MODE
283 glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
284 #endif
285 glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
286 glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
287 }
288
ImGui_ImplOpenGL3_CreateFontsTexture()289 bool ImGui_ImplOpenGL3_CreateFontsTexture()
290 {
291 // Build texture atlas
292 ImGuiIO& io = ImGui::GetIO();
293 unsigned char* pixels;
294 int width, height;
295 io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); // Load as RGBA 32-bits (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.
296
297 // Upload texture to graphics system
298 GLint last_texture;
299 glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
300 glGenTextures(1, &g_FontTexture);
301 glBindTexture(GL_TEXTURE_2D, g_FontTexture);
302 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
303 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
304 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
305 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
306
307 // Store our identifier
308 io.Fonts->TexID = (ImTextureID)(intptr_t)g_FontTexture;
309
310 // Restore state
311 glBindTexture(GL_TEXTURE_2D, last_texture);
312
313 return true;
314 }
315
ImGui_ImplOpenGL3_DestroyFontsTexture()316 void ImGui_ImplOpenGL3_DestroyFontsTexture()
317 {
318 if (g_FontTexture)
319 {
320 ImGuiIO& io = ImGui::GetIO();
321 glDeleteTextures(1, &g_FontTexture);
322 io.Fonts->TexID = 0;
323 g_FontTexture = 0;
324 }
325 }
326
327 // 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)328 static bool CheckShader(GLuint handle, const char* desc)
329 {
330 GLint status = 0, log_length = 0;
331 glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
332 glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
333 if ((GLboolean)status == GL_FALSE)
334 fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile %s!\n", desc);
335 if (log_length > 0)
336 {
337 ImVector<char> buf;
338 buf.resize((int)(log_length + 1));
339 glGetShaderInfoLog(handle, log_length, NULL, (GLchar*)buf.begin());
340 fprintf(stderr, "%s\n", buf.begin());
341 }
342 return (GLboolean)status == GL_TRUE;
343 }
344
345 // 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)346 static bool CheckProgram(GLuint handle, const char* desc)
347 {
348 GLint status = 0, log_length = 0;
349 glGetProgramiv(handle, GL_LINK_STATUS, &status);
350 glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
351 if ((GLboolean)status == GL_FALSE)
352 fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! (with GLSL '%s')\n", desc, g_GlslVersionString);
353 if (log_length > 0)
354 {
355 ImVector<char> buf;
356 buf.resize((int)(log_length + 1));
357 glGetProgramInfoLog(handle, log_length, NULL, (GLchar*)buf.begin());
358 fprintf(stderr, "%s\n", buf.begin());
359 }
360 return (GLboolean)status == GL_TRUE;
361 }
362
ImGui_ImplOpenGL3_CreateDeviceObjects()363 bool ImGui_ImplOpenGL3_CreateDeviceObjects()
364 {
365 // Backup GL state
366 GLint last_texture, last_array_buffer, last_vertex_array;
367 glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
368 glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
369 glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
370
371 // Parse GLSL version string
372 int glsl_version = 130;
373 sscanf(g_GlslVersionString, "#version %d", &glsl_version);
374
375 const GLchar* vertex_shader_glsl_120 =
376 "uniform mat4 ProjMtx;\n"
377 "attribute vec2 Position;\n"
378 "attribute vec2 UV;\n"
379 "attribute vec4 Color;\n"
380 "varying vec2 Frag_UV;\n"
381 "varying vec4 Frag_Color;\n"
382 "void main()\n"
383 "{\n"
384 " Frag_UV = UV;\n"
385 " Frag_Color = Color;\n"
386 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
387 "}\n";
388
389 const GLchar* vertex_shader_glsl_130 =
390 "uniform mat4 ProjMtx;\n"
391 "in vec2 Position;\n"
392 "in vec2 UV;\n"
393 "in vec4 Color;\n"
394 "out vec2 Frag_UV;\n"
395 "out vec4 Frag_Color;\n"
396 "void main()\n"
397 "{\n"
398 " Frag_UV = UV;\n"
399 " Frag_Color = Color;\n"
400 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
401 "}\n";
402
403 const GLchar* vertex_shader_glsl_300_es =
404 "precision mediump float;\n"
405 "layout (location = 0) in vec2 Position;\n"
406 "layout (location = 1) in vec2 UV;\n"
407 "layout (location = 2) in vec4 Color;\n"
408 "uniform mat4 ProjMtx;\n"
409 "out vec2 Frag_UV;\n"
410 "out vec4 Frag_Color;\n"
411 "void main()\n"
412 "{\n"
413 " Frag_UV = UV;\n"
414 " Frag_Color = Color;\n"
415 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
416 "}\n";
417
418 const GLchar* vertex_shader_glsl_410_core =
419 "layout (location = 0) in vec2 Position;\n"
420 "layout (location = 1) in vec2 UV;\n"
421 "layout (location = 2) in vec4 Color;\n"
422 "uniform mat4 ProjMtx;\n"
423 "out vec2 Frag_UV;\n"
424 "out vec4 Frag_Color;\n"
425 "void main()\n"
426 "{\n"
427 " Frag_UV = UV;\n"
428 " Frag_Color = Color;\n"
429 " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
430 "}\n";
431
432 const GLchar* fragment_shader_glsl_120 =
433 "#ifdef GL_ES\n"
434 " precision mediump float;\n"
435 "#endif\n"
436 "uniform sampler2D Texture;\n"
437 "varying vec2 Frag_UV;\n"
438 "varying vec4 Frag_Color;\n"
439 "void main()\n"
440 "{\n"
441 " gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
442 "}\n";
443
444 const GLchar* fragment_shader_glsl_130 =
445 "uniform sampler2D Texture;\n"
446 "in vec2 Frag_UV;\n"
447 "in vec4 Frag_Color;\n"
448 "out vec4 Out_Color;\n"
449 "void main()\n"
450 "{\n"
451 " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
452 "}\n";
453
454 const GLchar* fragment_shader_glsl_300_es =
455 "precision mediump float;\n"
456 "uniform sampler2D Texture;\n"
457 "in vec2 Frag_UV;\n"
458 "in vec4 Frag_Color;\n"
459 "layout (location = 0) out vec4 Out_Color;\n"
460 "void main()\n"
461 "{\n"
462 " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
463 "}\n";
464
465 const GLchar* fragment_shader_glsl_410_core =
466 "in vec2 Frag_UV;\n"
467 "in vec4 Frag_Color;\n"
468 "uniform sampler2D Texture;\n"
469 "layout (location = 0) out vec4 Out_Color;\n"
470 "void main()\n"
471 "{\n"
472 " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
473 "}\n";
474
475 // Select shaders matching our GLSL versions
476 const GLchar* vertex_shader = NULL;
477 const GLchar* fragment_shader = NULL;
478 if (glsl_version < 130)
479 {
480 vertex_shader = vertex_shader_glsl_120;
481 fragment_shader = fragment_shader_glsl_120;
482 }
483 else if (glsl_version >= 410)
484 {
485 vertex_shader = vertex_shader_glsl_410_core;
486 fragment_shader = fragment_shader_glsl_410_core;
487 }
488 else if (glsl_version == 300)
489 {
490 vertex_shader = vertex_shader_glsl_300_es;
491 fragment_shader = fragment_shader_glsl_300_es;
492 }
493 else
494 {
495 vertex_shader = vertex_shader_glsl_130;
496 fragment_shader = fragment_shader_glsl_130;
497 }
498
499 // Create shaders
500 const GLchar* vertex_shader_with_version[2] = { g_GlslVersionString, vertex_shader };
501 g_VertHandle = glCreateShader(GL_VERTEX_SHADER);
502 glShaderSource(g_VertHandle, 2, vertex_shader_with_version, NULL);
503 glCompileShader(g_VertHandle);
504 CheckShader(g_VertHandle, "vertex shader");
505
506 const GLchar* fragment_shader_with_version[2] = { g_GlslVersionString, fragment_shader };
507 g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER);
508 glShaderSource(g_FragHandle, 2, fragment_shader_with_version, NULL);
509 glCompileShader(g_FragHandle);
510 CheckShader(g_FragHandle, "fragment shader");
511
512 g_ShaderHandle = glCreateProgram();
513 glAttachShader(g_ShaderHandle, g_VertHandle);
514 glAttachShader(g_ShaderHandle, g_FragHandle);
515 glLinkProgram(g_ShaderHandle);
516 CheckProgram(g_ShaderHandle, "shader program");
517
518 g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture");
519 g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx");
520 g_AttribLocationPosition = glGetAttribLocation(g_ShaderHandle, "Position");
521 g_AttribLocationUV = glGetAttribLocation(g_ShaderHandle, "UV");
522 g_AttribLocationColor = glGetAttribLocation(g_ShaderHandle, "Color");
523
524 // Create buffers
525 glGenBuffers(1, &g_VboHandle);
526 glGenBuffers(1, &g_ElementsHandle);
527
528 ImGui_ImplOpenGL3_CreateFontsTexture();
529
530 // Restore modified GL state
531 glBindTexture(GL_TEXTURE_2D, last_texture);
532 glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
533 glBindVertexArray(last_vertex_array);
534
535 return true;
536 }
537
ImGui_ImplOpenGL3_DestroyDeviceObjects()538 void ImGui_ImplOpenGL3_DestroyDeviceObjects()
539 {
540 if (g_VboHandle) glDeleteBuffers(1, &g_VboHandle);
541 if (g_ElementsHandle) glDeleteBuffers(1, &g_ElementsHandle);
542 g_VboHandle = g_ElementsHandle = 0;
543
544 if (g_ShaderHandle && g_VertHandle) glDetachShader(g_ShaderHandle, g_VertHandle);
545 if (g_VertHandle) glDeleteShader(g_VertHandle);
546 g_VertHandle = 0;
547
548 if (g_ShaderHandle && g_FragHandle) glDetachShader(g_ShaderHandle, g_FragHandle);
549 if (g_FragHandle) glDeleteShader(g_FragHandle);
550 g_FragHandle = 0;
551
552 if (g_ShaderHandle) glDeleteProgram(g_ShaderHandle);
553 g_ShaderHandle = 0;
554
555 ImGui_ImplOpenGL3_DestroyFontsTexture();
556 }
557