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source: opengl-game/IMGUI/imgui_impl_opengl3.cpp@ 670c09a

feature/imgui-sdl

Last change on this file since 670c09a 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

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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>
113	using 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>
120	using 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
137	static GLuint g_GlVersion = 0; // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
138	static char g_GlslVersionString[32] = ""; // Specified by user or detected based on compile time GL settings.
139	static GLuint g_FontTexture = 0;
140	static GLuint g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
141	static GLint g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; // Uniforms location
142	static GLuint g_AttribLocationVtxPos = 0, g_AttribLocationVtxUV = 0, g_AttribLocationVtxColor = 0; // Vertex attributes location
143	static unsigned int g_VboHandle = 0, g_ElementsHandle = 0;
144
145	// Functions
146	bool 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
219	void ImGui_ImplOpenGL3_Shutdown()
220	{
221	ImGui_ImplOpenGL3_DestroyDeviceObjects();
222	}
223
224	void ImGui_ImplOpenGL3_NewFrame()
225	{
226	if (!g_ShaderHandle)
227	ImGui_ImplOpenGL3_CreateDeviceObjects();
228	}
229
230	static 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.
294	void 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
421	bool 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
450	void 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.
462	static 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.
480	static 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
497	bool 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
677	void 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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