// dear imgui: Renderer Backend for modern OpenGL with shaders / programmatic
// pipeline
// - Desktop GL: 2.x 3.x 4.x
// - Embedded GL: ES 2.0 (WebGL 1.0), ES 3.0 (WebGL 2.0)
// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32,
// custom..)
// Implemented features:
// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier
// as void*/ImTextureID. Read the FAQ about ImTextureID! [X] Renderer: Large
// meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
// [X] Renderer: Multi-viewport support (multiple windows). Enable with
// 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
// About WebGL/ES:
// - You need to '#define IMGUI_IMPL_OPENGL_ES2' or '#define
// IMGUI_IMPL_OPENGL_ES3' to use WebGL or OpenGL ES.
// - This is done automatically on iOS, Android and Emscripten targets.
// - For other targets, the define needs to be visible from the
// imgui_impl_opengl3.cpp compilation unit. If unsure, define globally or in
// imconfig.h.
// You can use unmodified imgui_impl_* files in your project. See examples/
// folder for examples of using this. Prefer including the entire imgui/
// repository into your project (either as a copy or as a submodule), and only
// build the backends you need. Learn about Dear ImGui:
// - FAQ https://dearimgui.com/faq
// - Getting Started https://dearimgui.com/getting-started
// - Documentation https://dearimgui.com/docs (same as your local docs/
// folder).
// - Introduction, links and more at the top of imgui.cpp
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2024-XX-XX: Platform: Added support for multiple windows via the
// ImGuiPlatformIO interface. 2024-01-09: OpenGL: Update GL3W based
// imgui_impl_opengl3_loader.h to load "libGL.so" and variants, fixing
// regression on distros missing a symlink. 2023-11-08: OpenGL: Update GL3W
// based imgui_impl_opengl3_loader.h to load "libGL.so" instead of
// "libGL.so.1", accommodating for NetBSD systems having only "libGL.so.3"
// available. (#6983) 2023-10-05: OpenGL: Rename symbols in our internal loader
// so that LTO compilation with another copy of gl3w is possible. (#6875,
// #6668, #4445) 2023-06-20: OpenGL: Fixed erroneous use
// glGetIntegerv(GL_CONTEXT_PROFILE_MASK) on contexts lower than 3.2. (#6539,
// #6333) 2023-05-09: OpenGL: Support for glBindSampler() backup/restore on
// ES3. (#6375) 2023-04-18: OpenGL: Restore front and back polygon mode
// separately when supported by context. (#6333) 2023-03-23: OpenGL: Properly
// restoring "no shader program bound" if it was the case prior to running the
// rendering function. (#6267, #6220, #6224) 2023-03-15: OpenGL: Fixed GL
// loader crash when GL_VERSION returns NULL. (#6154, #4445, #3530) 2023-03-06:
// OpenGL: Fixed restoration of a potentially deleted OpenGL program, by
// calling glIsProgram(). (#6220, #6224) 2022-11-09: OpenGL: Reverted use of
// glBufferSubData(), too many corruptions issues + old issues seemingly can't
// be reproed with Intel drivers nowadays (revert 2021-12-15 and 2022-05-23
// changes). 2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to
// C++11. 2022-09-27: OpenGL: Added ability to '#define
// IMGUI_IMPL_OPENGL_DEBUG'. 2022-05-23: OpenGL: Reworking 2021-12-15 "Using
// buffer orphaning" so it only happens on Intel GPU, seems to cause problems
// otherwise. (#4468, #4825, #4832, #5127). 2022-05-13: OpenGL: Fixed state
// corruption on OpenGL ES 2.0 due to not preserving
// GL_ELEMENT_ARRAY_BUFFER_BINDING and vertex attribute states. 2021-12-15:
// OpenGL: Using buffer orphaning + glBufferSubData(), seems to fix leaks with
// multi-viewports with some Intel HD drivers. 2021-08-23: OpenGL: Fixed ES 3.0
// shader ("#version 300 es") use normal precision floats to avoid wobbly
// rendering at HD resolutions. 2021-08-19: OpenGL: Embed and use our own
// minimal GL loader (imgui_impl_opengl3_loader.h), removing requirement and
// support for third-party loader. 2021-06-29: Reorganized backend to pull data
// from a single structure to facilitate usage with multiple-contexts (all
// g_XXXX access changed to bd->XXXX). 2021-06-25: OpenGL: Use OES_vertex_array
// extension on Emscripten + backup/restore current state. 2021-06-21: OpenGL:
// Destroy individual vertex/fragment shader objects right after they are
// linked into the main shader. 2021-05-24: OpenGL: Access GL_CLIP_ORIGIN when
// "GL_ARB_clip_control" extension is detected, inside of just OpenGL 4.5
// version. 2021-05-19: OpenGL: Replaced direct access to ImDrawCmd::TextureId
// with a call to ImDrawCmd::GetTexID(). (will become a requirement)
// 2021-04-06: OpenGL: Don't try to read GL_CLIP_ORIGIN unless we're OpenGL 4.5
// or greater. 2021-02-18: OpenGL: Change blending equation to preserve alpha
// in output buffer. 2021-01-03: OpenGL: Backup, setup and restore
// GL_STENCIL_TEST state. 2020-10-23: OpenGL: Backup, setup and restore
// GL_PRIMITIVE_RESTART state. 2020-10-15: OpenGL: Use glGetString(GL_VERSION)
// instead of glGetIntegerv(GL_MAJOR_VERSION, ...) when the later returns zero
// (e.g. Desktop GL 2.x) 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. 2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
// 2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
// 2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by
// inverting projection matrix. 2020-04-12: OpenGL: Fixed context version check
// mistakenly testing for 4.0+ instead of 3.2+ to enable
// ImGuiBackendFlags_RendererHasVtxOffset. 2020-03-24: OpenGL: Added support
// for glbinding 2.x OpenGL loader. 2020-01-07: OpenGL: Added support for
// glbinding 3.x OpenGL loader. 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.
// 2019-09-22: OpenGL: Detect default GL loader using __has_include compiler
// facility. 2019-09-16: OpenGL: Tweak initialization code to allow application
// calling ImGui_ImplOpenGL3_CreateFontsTexture() before the first NewFrame()
// call. 2019-05-29: OpenGL: Desktop GL only: Added support for large mesh
// (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
// 2019-04-30: OpenGL: Added support for special
// ImDrawCallback_ResetRenderState callback to reset render state. 2019-03-29:
// OpenGL: Not calling glBindBuffer more than necessary in the render loop.
// 2019-03-15: OpenGL: Added a GL call + comments in ImGui_ImplOpenGL3_Init()
// to detect uninitialized GL function loaders early. 2019-03-03: OpenGL: Fix
// support for ES 2.0 (WebGL 1.0). 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. 2019-02-11: OpenGL: Projecting clipping rectangles
// correctly using draw_data->FramebufferScale to allow multi-viewports for
// retina display. 2019-02-01: OpenGL: Using GLSL 410 shaders for any version
// over 410 (e.g. 430, 450). 2018-11-30: Misc: Setting up
// io.BackendRendererName so it can be displayed in the About Window.
// 2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT) /
// GL_CLIP_ORIGIN. 2018-08-29: OpenGL: Added support for more OpenGL loaders:
// glew and glad, with comments indicative that any loader can be used.
// 2018-08-09: OpenGL: Default to OpenGL ES 3 on iOS and Android. GLSL version
// default to "#version 300 ES". 2018-07-30: OpenGL: Support for GLSL 300 ES
// and 410 core. Fixes for Emscripten compilation. 2018-07-10: OpenGL: Support
// for more GLSL versions (based on the GLSL version string). Added error
// output when shaders fail to compile/link. 2018-06-08: Misc: Extracted
// imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3
// examples. 2018-06-08: OpenGL: Use draw_data->DisplayPos and
// draw_data->DisplaySize to setup projection matrix and clipping rectangle.
// 2018-05-25: OpenGL: Removed unnecessary backup/restore of
// GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
// 2018-05-14: OpenGL: Making the call to glBindSampler() optional so 3.2
// context won't fail if the function is a nullptr pointer. 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". 2018-02-23: OpenGL:
// Create the VAO in the render function so the setup can more easily be used
// with multiple shared GL context. 2018-02-16: Misc: Obsoleted the
// io.RenderDrawListsFn callback and exposed ImGui_ImplSdlGL3_RenderDrawData()
// in the .h file so you can call it yourself. 2018-01-07: OpenGL: Changed GLSL
// shader version from 330 to 150. 2017-09-01: OpenGL: Save and restore current
// bound sampler. Save and restore current polygon mode. 2017-05-01: OpenGL:
// Fixed save and restore of current blend func state. 2017-05-01: OpenGL:
// Fixed save and restore of current GL_ACTIVE_TEXTURE. 2016-09-05: OpenGL:
// Fixed save and restore of current scissor rectangle. 2016-07-29: OpenGL:
// Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes
// it. (#752)
//----------------------------------------
// OpenGL GLSL GLSL
// version version string
//----------------------------------------
// 2.0 110 "#version 110"
// 2.1 120 "#version 120"
// 3.0 130 "#version 130"
// 3.1 140 "#version 140"
// 3.2 150 "#version 150"
// 3.3 330 "#version 330 core"
// 4.0 400 "#version 400 core"
// 4.1 410 "#version 410 core"
// 4.2 420 "#version 410 core"
// 4.3 430 "#version 430 core"
// ES 2.0 100 "#version 100" = WebGL 1.0
// ES 3.0 300 "#version 300 es" = WebGL 2.0
//----------------------------------------
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif
#include "../imgui.h"
#ifndef IMGUI_DISABLE
#include "imgui_impl_opengl3.h"
#include <stdint.h> // intptr_t
#include <stdio.h>
#if defined(__APPLE__)
#include <TargetConditionals.h>
#endif
// Clang/GCC warnings with -Weverything
#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored \
"-Wold-style-cast" // warning: use of old-style cast
#pragma clang diagnostic ignored \
"-Wsign-conversion" // warning: implicit conversion changes signedness
#pragma clang diagnostic ignored "-Wunused-macros" // warning: macro is not used
#pragma clang diagnostic ignored "-Wnonportable-system-include-path"
#pragma clang diagnostic ignored \
"-Wcast-function-type" // warning: cast between incompatible function types
// (for loader)
#endif
#if defined(__GNUC__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored \
"-Wpragmas" // warning: unknown option after '#pragma GCC diagnostic' kind
#pragma GCC diagnostic ignored \
"-Wunknown-warning-option" // warning: unknown warning group 'xxx'
#pragma GCC diagnostic ignored \
"-Wcast-function-type" // warning: cast between incompatible function types
// (for loader)
#endif
// GL includes
#if defined(IMGUI_IMPL_OPENGL_ES2)
#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
#include <OpenGLES/ES2/gl.h> // Use GL ES 2
#else
#include <GLES2/gl2.h> // Use GL ES 2
#endif
#if defined(__EMSCRIPTEN__)
#ifndef GL_GLEXT_PROTOTYPES
#define GL_GLEXT_PROTOTYPES
#endif
#include <GLES2/gl2ext.h>
#endif
#elif defined(IMGUI_IMPL_OPENGL_ES3)
#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
#include <OpenGLES/ES3/gl.h> // Use GL ES 3
#else
#include <GLES3/gl3.h> // Use GL ES 3
#endif
#elif !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
// Modern desktop OpenGL doesn't have a standard portable header file to load
// OpenGL function pointers. Helper libraries are often used for this purpose!
// Here we are using our own minimal custom loader based on gl3w. In the rest of
// your app/engine, you can use another loader of your choice (gl3w, glew, glad,
// glbinding, glext, glLoadGen, etc.). If you happen to be developing a new
// feature for this backend (imgui_impl_opengl3.cpp):
// - You may need to regenerate imgui_impl_opengl3_loader.h to add new symbols.
// See https://github.com/dearimgui/gl3w_stripped
// - You can temporarily use an unstripped version. See
// https://github.com/dearimgui/gl3w_stripped/releases Changes to this backend
// using new APIs should be accompanied by a regenerated stripped loader
// version.
#define IMGL3W_IMPL
#include "imgui_impl_opengl3_loader.h"
#endif
// Vertex arrays are not supported on ES2/WebGL1 unless Emscripten which uses an
// extension
#ifndef IMGUI_IMPL_OPENGL_ES2
#define IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
#elif defined(__EMSCRIPTEN__)
#define IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
#define glBindVertexArray glBindVertexArrayOES
#define glGenVertexArrays glGenVertexArraysOES
#define glDeleteVertexArrays glDeleteVertexArraysOES
#define GL_VERTEX_ARRAY_BINDING GL_VERTEX_ARRAY_BINDING_OES
#endif
// Desktop GL 2.0+ has extension and glPolygonMode() which GL ES and WebGL don't
// have..
#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3)
#define IMGUI_IMPL_OPENGL_HAS_EXTENSIONS // has glGetIntegerv(GL_NUM_EXTENSIONS)
#define IMGUI_IMPL_OPENGL_HAS_POLYGON_MODE // has glPolygonMode()
#endif
// Desktop GL 2.1+ and GL ES 3.0+ have glBindBuffer() with
// GL_PIXEL_UNPACK_BUFFER target.
#if !defined(IMGUI_IMPL_OPENGL_ES2)
#define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_BUFFER_PIXEL_UNPACK
#endif
// Desktop GL 3.1+ has GL_PRIMITIVE_RESTART state
#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && \
defined(GL_VERSION_3_1)
#define IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
#endif
// Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't
// have.
#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && \
defined(GL_VERSION_3_2)
#define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
#endif
// Desktop GL 3.3+ and GL ES 3.0+ have glBindSampler()
#if !defined(IMGUI_IMPL_OPENGL_ES2) && \
(defined(IMGUI_IMPL_OPENGL_ES3) || defined(GL_VERSION_3_3))
#define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
#endif
// [Debugging]
// #define IMGUI_IMPL_OPENGL_DEBUG
#ifdef IMGUI_IMPL_OPENGL_DEBUG
#include <stdio.h>
#define GL_CALL(_CALL) \
do { \
_CALL; \
GLenum gl_err = glGetError(); \
if (gl_err != 0) \
fprintf(stderr, "GL error 0x%x returned from '%s'.\n", gl_err, #_CALL); \
} while (0) // Call with error check
#else
#define GL_CALL(_CALL) _CALL // Call without error check
#endif
// OpenGL Data
struct ImGui_ImplOpenGL3_Data {
GLuint GlVersion; // Extracted at runtime using GL_MAJOR_VERSION,
// GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
char GlslVersionString[32]; // Specified by user or detected based on compile
// time GL settings.
bool GlProfileIsES2;
bool GlProfileIsES3;
bool GlProfileIsCompat;
GLint GlProfileMask;
GLuint FontTexture;
GLuint ShaderHandle;
GLint AttribLocationTex; // Uniforms location
GLint AttribLocationProjMtx;
GLuint AttribLocationVtxPos; // Vertex attributes location
GLuint AttribLocationVtxUV;
GLuint AttribLocationVtxColor;
unsigned int VboHandle, ElementsHandle;
GLsizeiptr VertexBufferSize;
GLsizeiptr IndexBufferSize;
bool HasClipOrigin;
bool UseBufferSubData;
ImGui_ImplOpenGL3_Data() { memset((void *)this, 0, sizeof(*this)); }
};
// Backend data stored in io.BackendRendererUserData to allow support for
// multiple Dear ImGui contexts It is STRONGLY preferred that you use docking
// branch with multi-viewports (== single Dear ImGui context + multiple windows)
// instead of multiple Dear ImGui contexts.
static ImGui_ImplOpenGL3_Data *ImGui_ImplOpenGL3_GetBackendData() {
return ImGui::GetCurrentContext()
? (ImGui_ImplOpenGL3_Data *)ImGui::GetIO().BackendRendererUserData
: nullptr;
}
// Forward Declarations
static void ImGui_ImplOpenGL3_InitPlatformInterface();
static void ImGui_ImplOpenGL3_ShutdownPlatformInterface();
// OpenGL vertex attribute state (for ES 1.0 and ES 2.0 only)
#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
struct ImGui_ImplOpenGL3_VtxAttribState {
GLint Enabled, Size, Type, Normalized, Stride;
GLvoid *Ptr;
void GetState(GLint index) {
glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_ENABLED, &Enabled);
glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_SIZE, &Size);
glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_TYPE, &Type);
glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_NORMALIZED, &Normalized);
glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_STRIDE, &Stride);
glGetVertexAttribPointerv(index, GL_VERTEX_ATTRIB_ARRAY_POINTER, &Ptr);
}
void SetState(GLint index) {
glVertexAttribPointer(index, Size, Type, (GLboolean)Normalized, Stride,
Ptr);
if (Enabled)
glEnableVertexAttribArray(index);
else
glDisableVertexAttribArray(index);
}
};
#endif
// Functions
bool ImGui_ImplOpenGL3_Init(const char *glsl_version) {
ImGuiIO &io = ImGui::GetIO();
IM_ASSERT(io.BackendRendererUserData == nullptr &&
"Already initialized a renderer backend!");
// Initialize our loader
#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && \
!defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
if (imgl3wInit() != 0) {
fprintf(stderr, "Failed to initialize OpenGL loader!\n");
return false;
}
#endif
// Setup backend capabilities flags
ImGui_ImplOpenGL3_Data *bd = IM_NEW(ImGui_ImplOpenGL3_Data)();
io.BackendRendererUserData = (void *)bd;
io.BackendRendererName = "imgui_impl_opengl3";
// Query for GL version (e.g. 320 for GL 3.2)
#if defined(IMGUI_IMPL_OPENGL_ES2)
// GLES 2
bd->GlVersion = 200;
bd->GlProfileIsES2 = true;
#else
// Desktop or GLES 3
GLint major = 0;
GLint minor = 0;
glGetIntegerv(GL_MAJOR_VERSION, &major);
glGetIntegerv(GL_MINOR_VERSION, &minor);
if (major == 0 && minor == 0) {
// Query GL_VERSION in desktop GL 2.x, the string will start with
// "<major>.<minor>"
const char *gl_version = (const char *)glGetString(GL_VERSION);
sscanf(gl_version, "%d.%d", &major, &minor);
}
bd->GlVersion = (GLuint)(major * 100 + minor * 10);
#if defined(GL_CONTEXT_PROFILE_MASK)
if (bd->GlVersion >= 320)
glGetIntegerv(GL_CONTEXT_PROFILE_MASK, &bd->GlProfileMask);
bd->GlProfileIsCompat =
(bd->GlProfileMask & GL_CONTEXT_COMPATIBILITY_PROFILE_BIT) != 0;
#endif
#if defined(IMGUI_IMPL_OPENGL_ES3)
bd->GlProfileIsES3 = true;
#endif
bd->UseBufferSubData = false;
/*
// Query vendor to enable glBufferSubData kludge
#ifdef _WIN32
if (const char* vendor = (const char*)glGetString(GL_VENDOR))
if (strncmp(vendor, "Intel", 5) == 0)
bd->UseBufferSubData = true;
#endif
*/
#endif
#ifdef IMGUI_IMPL_OPENGL_DEBUG
printf("GlVersion = %d\nGlProfileIsCompat = %d\nGlProfileMask = "
"0x%X\nGlProfileIsES2 = %d, GlProfileIsES3 = %d\nGL_VENDOR = "
"'%s'\nGL_RENDERER = '%s'\n",
bd->GlVersion, bd->GlProfileIsCompat, bd->GlProfileMask,
bd->GlProfileIsES2, bd->GlProfileIsES3,
(const char *)glGetString(GL_VENDOR),
(const char *)glGetString(GL_RENDERER)); // [DEBUG]
#endif
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
if (bd->GlVersion >= 320)
io.BackendFlags |=
ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the
// ImDrawCmd::VtxOffset field,
// allowing for large meshes.
#endif
io.BackendFlags |=
ImGuiBackendFlags_RendererHasViewports; // We can create multi-viewports
// on the Renderer side (optional)
// 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
// nullptr if unsure.
if (glsl_version == nullptr) {
#if defined(IMGUI_IMPL_OPENGL_ES2)
glsl_version = "#version 100";
#elif defined(IMGUI_IMPL_OPENGL_ES3)
glsl_version = "#version 300 es";
#elif defined(__APPLE__)
glsl_version = "#version 150";
#else
glsl_version = "#version 130";
#endif
}
IM_ASSERT((int)strlen(glsl_version) + 2 <
IM_ARRAYSIZE(bd->GlslVersionString));
strcpy(bd->GlslVersionString, glsl_version);
strcat(bd->GlslVersionString, "\n");
// Make an arbitrary GL call (we don't actually need the result)
// IF YOU GET A CRASH HERE: it probably means the OpenGL function loader
// didn't do its job. Let us know!
GLint current_texture;
glGetIntegerv(GL_TEXTURE_BINDING_2D, ¤t_texture);
// Detect extensions we support
bd->HasClipOrigin = (bd->GlVersion >= 450);
#ifdef IMGUI_IMPL_OPENGL_HAS_EXTENSIONS
GLint num_extensions = 0;
glGetIntegerv(GL_NUM_EXTENSIONS, &num_extensions);
for (GLint i = 0; i < num_extensions; i++) {
const char *extension = (const char *)glGetStringi(GL_EXTENSIONS, i);
if (extension != nullptr && strcmp(extension, "GL_ARB_clip_control") == 0)
bd->HasClipOrigin = true;
}
#endif
if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
ImGui_ImplOpenGL3_InitPlatformInterface();
return true;
}
void ImGui_ImplOpenGL3_Shutdown() {
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
IM_ASSERT(bd != nullptr &&
"No renderer backend to shutdown, or already shutdown?");
ImGuiIO &io = ImGui::GetIO();
ImGui_ImplOpenGL3_ShutdownPlatformInterface();
ImGui_ImplOpenGL3_DestroyDeviceObjects();
io.BackendRendererName = nullptr;
io.BackendRendererUserData = nullptr;
io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset |
ImGuiBackendFlags_RendererHasViewports);
IM_DELETE(bd);
}
void ImGui_ImplOpenGL3_NewFrame() {
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplOpenGL3_Init()?");
if (!bd->ShaderHandle)
ImGui_ImplOpenGL3_CreateDeviceObjects();
}
static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData *draw_data,
int fb_width, int fb_height,
GLuint vertex_array_object) {
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
// Setup render state: alpha-blending enabled, no face culling, no depth
// testing, scissor enabled, polygon fill
glEnable(GL_BLEND);
glBlendEquation(GL_FUNC_ADD);
glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE,
GL_ONE_MINUS_SRC_ALPHA);
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_TEST);
glDisable(GL_STENCIL_TEST);
glEnable(GL_SCISSOR_TEST);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
if (bd->GlVersion >= 310)
glDisable(GL_PRIMITIVE_RESTART);
#endif
#ifdef IMGUI_IMPL_OPENGL_HAS_POLYGON_MODE
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
#endif
// Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT)
#if defined(GL_CLIP_ORIGIN)
bool clip_origin_lower_left = true;
if (bd->HasClipOrigin) {
GLenum current_clip_origin = 0;
glGetIntegerv(GL_CLIP_ORIGIN, (GLint *)¤t_clip_origin);
if (current_clip_origin == GL_UPPER_LEFT)
clip_origin_lower_left = false;
}
#endif
// Setup viewport, orthographic projection matrix
// 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.
GL_CALL(glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height));
float L = draw_data->DisplayPos.x;
float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
float T = draw_data->DisplayPos.y;
float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
#if defined(GL_CLIP_ORIGIN)
if (!clip_origin_lower_left) {
float tmp = T;
T = B;
B = tmp;
} // Swap top and bottom if origin is upper left
#endif
const float ortho_projection[4][4] = {
{2.0f / (R - L), 0.0f, 0.0f, 0.0f},
{0.0f, 2.0f / (T - B), 0.0f, 0.0f},
{0.0f, 0.0f, -1.0f, 0.0f},
{(R + L) / (L - R), (T + B) / (B - T), 0.0f, 1.0f},
};
glUseProgram(bd->ShaderHandle);
glUniform1i(bd->AttribLocationTex, 0);
glUniformMatrix4fv(bd->AttribLocationProjMtx, 1, GL_FALSE,
&ortho_projection[0][0]);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
if (bd->GlVersion >= 330 || bd->GlProfileIsES3)
glBindSampler(0, 0); // We use combined texture/sampler state. Applications
// using GL 3.3 and GL ES 3.0 may set that otherwise.
#endif
(void)vertex_array_object;
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
glBindVertexArray(vertex_array_object);
#endif
// Bind vertex/index buffers and setup attributes for ImDrawVert
GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, bd->VboHandle));
GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bd->ElementsHandle));
GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxPos));
GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxUV));
GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxColor));
GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE,
sizeof(ImDrawVert),
(GLvoid *)offsetof(ImDrawVert, pos)));
GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE,
sizeof(ImDrawVert),
(GLvoid *)offsetof(ImDrawVert, uv)));
GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE,
GL_TRUE, sizeof(ImDrawVert),
(GLvoid *)offsetof(ImDrawVert, col)));
}
// OpenGL3 Render function.
// Note that this implementation is little overcomplicated because we are
// saving/setting up/restoring every OpenGL state explicitly. This is in order
// to be able to run within an OpenGL engine that doesn't do so.
void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData *draw_data) {
// Avoid rendering when minimized, scale coordinates for retina displays
// (screen coordinates != framebuffer coordinates)
int fb_width =
(int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
int fb_height =
(int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
if (fb_width <= 0 || fb_height <= 0)
return;
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
// Backup GL state
GLenum last_active_texture;
glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint *)&last_active_texture);
glActiveTexture(GL_TEXTURE0);
GLuint last_program;
glGetIntegerv(GL_CURRENT_PROGRAM, (GLint *)&last_program);
GLuint last_texture;
glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint *)&last_texture);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
GLuint last_sampler;
if (bd->GlVersion >= 330 || bd->GlProfileIsES3) {
glGetIntegerv(GL_SAMPLER_BINDING, (GLint *)&last_sampler);
} else {
last_sampler = 0;
}
#endif
GLuint last_array_buffer;
glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint *)&last_array_buffer);
#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
// This is part of VAO on OpenGL 3.0+ and OpenGL ES 3.0+.
GLint last_element_array_buffer;
glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer);
ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_pos;
last_vtx_attrib_state_pos.GetState(bd->AttribLocationVtxPos);
ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_uv;
last_vtx_attrib_state_uv.GetState(bd->AttribLocationVtxUV);
ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_color;
last_vtx_attrib_state_color.GetState(bd->AttribLocationVtxColor);
#endif
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
GLuint last_vertex_array_object;
glGetIntegerv(GL_VERTEX_ARRAY_BINDING, (GLint *)&last_vertex_array_object);
#endif
#ifdef IMGUI_IMPL_OPENGL_HAS_POLYGON_MODE
GLint last_polygon_mode[2];
glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
#endif
GLint last_viewport[4];
glGetIntegerv(GL_VIEWPORT, last_viewport);
GLint last_scissor_box[4];
glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
GLenum last_blend_src_rgb;
glGetIntegerv(GL_BLEND_SRC_RGB, (GLint *)&last_blend_src_rgb);
GLenum last_blend_dst_rgb;
glGetIntegerv(GL_BLEND_DST_RGB, (GLint *)&last_blend_dst_rgb);
GLenum last_blend_src_alpha;
glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint *)&last_blend_src_alpha);
GLenum last_blend_dst_alpha;
glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint *)&last_blend_dst_alpha);
GLenum last_blend_equation_rgb;
glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint *)&last_blend_equation_rgb);
GLenum last_blend_equation_alpha;
glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint *)&last_blend_equation_alpha);
GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
GLboolean last_enable_stencil_test = glIsEnabled(GL_STENCIL_TEST);
GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
GLboolean last_enable_primitive_restart =
(bd->GlVersion >= 310) ? glIsEnabled(GL_PRIMITIVE_RESTART) : GL_FALSE;
#endif
// Setup desired GL state
// Recreate the VAO every time (this is to easily allow multiple GL contexts
// to be rendered to. VAO are not shared among GL contexts) The renderer would
// actually work without any VAO bound, but then our VertexAttrib calls would
// overwrite the default one currently bound.
GLuint vertex_array_object = 0;
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
GL_CALL(glGenVertexArrays(1, &vertex_array_object));
#endif
ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height,
vertex_array_object);
// Will project scissor/clipping rectangles into framebuffer space
ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
ImVec2 clip_scale =
draw_data->FramebufferScale; // (1,1) unless using retina display which
// are often (2,2)
// Render command lists
for (int n = 0; n < draw_data->CmdListsCount; n++) {
const ImDrawList *cmd_list = draw_data->CmdLists[n];
// Upload vertex/index buffers
// - OpenGL drivers are in a very sorry state nowadays....
// During 2021 we attempted to switch from glBufferData() to
// orphaning+glBufferSubData() following reports of leaks on Intel GPU
// when using multi-viewports on Windows.
// - After this we kept hearing of various display corruptions issues. We
// started disabling on non-Intel GPU, but issues still got reported on
// Intel.
// - We are now back to using exclusively glBufferData(). So
// bd->UseBufferSubData IS ALWAYS FALSE in this code.
// We are keeping the old code path for a while in case people finding new
// issues may want to test the bd->UseBufferSubData path.
// - See https://github.com/ocornut/imgui/issues/4468 and please report any
// corruption issues.
const GLsizeiptr vtx_buffer_size =
(GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert);
const GLsizeiptr idx_buffer_size =
(GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx);
if (bd->UseBufferSubData) {
if (bd->VertexBufferSize < vtx_buffer_size) {
bd->VertexBufferSize = vtx_buffer_size;
GL_CALL(glBufferData(GL_ARRAY_BUFFER, bd->VertexBufferSize, nullptr,
GL_STREAM_DRAW));
}
if (bd->IndexBufferSize < idx_buffer_size) {
bd->IndexBufferSize = idx_buffer_size;
GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, bd->IndexBufferSize,
nullptr, GL_STREAM_DRAW));
}
GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, vtx_buffer_size,
(const GLvoid *)cmd_list->VtxBuffer.Data));
GL_CALL(glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, idx_buffer_size,
(const GLvoid *)cmd_list->IdxBuffer.Data));
} else {
GL_CALL(glBufferData(GL_ARRAY_BUFFER, vtx_buffer_size,
(const GLvoid *)cmd_list->VtxBuffer.Data,
GL_STREAM_DRAW));
GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx_buffer_size,
(const GLvoid *)cmd_list->IdxBuffer.Data,
GL_STREAM_DRAW));
}
for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++) {
const ImDrawCmd *pcmd = &cmd_list->CmdBuffer[cmd_i];
if (pcmd->UserCallback != nullptr) {
// User callback, registered via ImDrawList::AddCallback()
// (ImDrawCallback_ResetRenderState is a special callback value used by
// the user to request the renderer to reset render state.)
if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height,
vertex_array_object);
else
pcmd->UserCallback(cmd_list, pcmd);
} else {
// Project scissor/clipping rectangles into framebuffer space
ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x,
(pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x,
(pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
continue;
// Apply scissor/clipping rectangle (Y is inverted in OpenGL)
GL_CALL(glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y),
(int)(clip_max.x - clip_min.x),
(int)(clip_max.y - clip_min.y)));
// Bind texture, Draw
GL_CALL(
glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID()));
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
if (bd->GlVersion >= 320)
GL_CALL(glDrawElementsBaseVertex(
GL_TRIANGLES, (GLsizei)pcmd->ElemCount,
sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT,
(void *)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)),
(GLint)pcmd->VtxOffset));
else
#endif
GL_CALL(glDrawElements(
GL_TRIANGLES, (GLsizei)pcmd->ElemCount,
sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT,
(void *)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))));
}
}
}
// Destroy the temporary VAO
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
GL_CALL(glDeleteVertexArrays(1, &vertex_array_object));
#endif
// Restore modified GL state
// This "glIsProgram()" check is required because if the program is "pending
// deletion" at the time of binding backup, it will have been deleted by now
// and will cause an OpenGL error. See #6220.
if (last_program == 0 || glIsProgram(last_program))
glUseProgram(last_program);
glBindTexture(GL_TEXTURE_2D, last_texture);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
if (bd->GlVersion >= 330 || bd->GlProfileIsES3)
glBindSampler(0, last_sampler);
#endif
glActiveTexture(last_active_texture);
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
glBindVertexArray(last_vertex_array_object);
#endif
glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, last_element_array_buffer);
last_vtx_attrib_state_pos.SetState(bd->AttribLocationVtxPos);
last_vtx_attrib_state_uv.SetState(bd->AttribLocationVtxUV);
last_vtx_attrib_state_color.SetState(bd->AttribLocationVtxColor);
#endif
glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb,
last_blend_src_alpha, last_blend_dst_alpha);
if (last_enable_blend)
glEnable(GL_BLEND);
else
glDisable(GL_BLEND);
if (last_enable_cull_face)
glEnable(GL_CULL_FACE);
else
glDisable(GL_CULL_FACE);
if (last_enable_depth_test)
glEnable(GL_DEPTH_TEST);
else
glDisable(GL_DEPTH_TEST);
if (last_enable_stencil_test)
glEnable(GL_STENCIL_TEST);
else
glDisable(GL_STENCIL_TEST);
if (last_enable_scissor_test)
glEnable(GL_SCISSOR_TEST);
else
glDisable(GL_SCISSOR_TEST);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
if (bd->GlVersion >= 310) {
if (last_enable_primitive_restart)
glEnable(GL_PRIMITIVE_RESTART);
else
glDisable(GL_PRIMITIVE_RESTART);
}
#endif
#ifdef IMGUI_IMPL_OPENGL_HAS_POLYGON_MODE
// Desktop OpenGL 3.0 and OpenGL 3.1 had separate polygon draw modes for
// front-facing and back-facing faces of polygons
if (bd->GlVersion <= 310 || bd->GlProfileIsCompat) {
glPolygonMode(GL_FRONT, (GLenum)last_polygon_mode[0]);
glPolygonMode(GL_BACK, (GLenum)last_polygon_mode[1]);
} else {
glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
}
#endif // IMGUI_IMPL_OPENGL_HAS_POLYGON_MODE
glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2],
(GLsizei)last_viewport[3]);
glScissor(last_scissor_box[0], last_scissor_box[1],
(GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
(void)bd; // Not all compilation paths use this
}
bool ImGui_ImplOpenGL3_CreateFontsTexture() {
ImGuiIO &io = ImGui::GetIO();
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
// Build texture atlas
unsigned char *pixels;
int width, height;
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.
// Upload texture to graphics system
// (Bilinear sampling is required by default. Set 'io.Fonts->Flags |=
// ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to
// allow point/nearest sampling)
GLint last_texture;
GL_CALL(glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture));
GL_CALL(glGenTextures(1, &bd->FontTexture));
GL_CALL(glBindTexture(GL_TEXTURE_2D, bd->FontTexture));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
#ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
#endif
GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA,
GL_UNSIGNED_BYTE, pixels));
// Store our identifier
io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
// Restore state
GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture));
return true;
}
void ImGui_ImplOpenGL3_DestroyFontsTexture() {
ImGuiIO &io = ImGui::GetIO();
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
if (bd->FontTexture) {
glDeleteTextures(1, &bd->FontTexture);
io.Fonts->SetTexID(0);
bd->FontTexture = 0;
}
}
// 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.
static bool CheckShader(GLuint handle, const char *desc) {
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
GLint status = 0, log_length = 0;
glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
if ((GLboolean)status == GL_FALSE)
fprintf(stderr,
"ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile "
"%s! With GLSL: %s\n",
desc, bd->GlslVersionString);
if (log_length > 1) {
ImVector<char> buf;
buf.resize((int)(log_length + 1));
glGetShaderInfoLog(handle, log_length, nullptr, (GLchar *)buf.begin());
fprintf(stderr, "%s\n", buf.begin());
}
return (GLboolean)status == GL_TRUE;
}
// If you get an error please report on GitHub. You may try different GL context
// version or GLSL version.
static bool CheckProgram(GLuint handle, const char *desc) {
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
GLint status = 0, log_length = 0;
glGetProgramiv(handle, GL_LINK_STATUS, &status);
glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
if ((GLboolean)status == GL_FALSE)
fprintf(stderr,
"ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! "
"With GLSL %s\n",
desc, bd->GlslVersionString);
if (log_length > 1) {
ImVector<char> buf;
buf.resize((int)(log_length + 1));
glGetProgramInfoLog(handle, log_length, nullptr, (GLchar *)buf.begin());
fprintf(stderr, "%s\n", buf.begin());
}
return (GLboolean)status == GL_TRUE;
}
bool ImGui_ImplOpenGL3_CreateDeviceObjects() {
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
// Backup GL state
GLint last_texture, last_array_buffer;
glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_BUFFER_PIXEL_UNPACK
GLint last_pixel_unpack_buffer;
if (bd->GlVersion >= 210) {
glGetIntegerv(GL_PIXEL_UNPACK_BUFFER_BINDING, &last_pixel_unpack_buffer);
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
}
#endif
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
GLint last_vertex_array;
glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
#endif
// Parse GLSL version string
int glsl_version = 130;
sscanf(bd->GlslVersionString, "#version %d", &glsl_version);
const GLchar *vertex_shader_glsl_120 =
"uniform mat4 ProjMtx;\n"
"attribute vec2 Position;\n"
"attribute vec2 UV;\n"
"attribute vec4 Color;\n"
"varying vec2 Frag_UV;\n"
"varying vec4 Frag_Color;\n"
"void main()\n"
"{\n"
" Frag_UV = UV;\n"
" Frag_Color = Color;\n"
" gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
"}\n";
const GLchar *vertex_shader_glsl_130 =
"uniform mat4 ProjMtx;\n"
"in vec2 Position;\n"
"in vec2 UV;\n"
"in vec4 Color;\n"
"out vec2 Frag_UV;\n"
"out vec4 Frag_Color;\n"
"void main()\n"
"{\n"
" Frag_UV = UV;\n"
" Frag_Color = Color;\n"
" gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
"}\n";
const GLchar *vertex_shader_glsl_300_es =
"precision highp float;\n"
"layout (location = 0) in vec2 Position;\n"
"layout (location = 1) in vec2 UV;\n"
"layout (location = 2) in vec4 Color;\n"
"uniform mat4 ProjMtx;\n"
"out vec2 Frag_UV;\n"
"out vec4 Frag_Color;\n"
"void main()\n"
"{\n"
" Frag_UV = UV;\n"
" Frag_Color = Color;\n"
" gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
"}\n";
const GLchar *vertex_shader_glsl_410_core =
"layout (location = 0) in vec2 Position;\n"
"layout (location = 1) in vec2 UV;\n"
"layout (location = 2) in vec4 Color;\n"
"uniform mat4 ProjMtx;\n"
"out vec2 Frag_UV;\n"
"out vec4 Frag_Color;\n"
"void main()\n"
"{\n"
" Frag_UV = UV;\n"
" Frag_Color = Color;\n"
" gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
"}\n";
const GLchar *fragment_shader_glsl_120 =
"#ifdef GL_ES\n"
" precision mediump float;\n"
"#endif\n"
"uniform sampler2D Texture;\n"
"varying vec2 Frag_UV;\n"
"varying vec4 Frag_Color;\n"
"void main()\n"
"{\n"
" gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
"}\n";
const GLchar *fragment_shader_glsl_130 =
"uniform sampler2D Texture;\n"
"in vec2 Frag_UV;\n"
"in vec4 Frag_Color;\n"
"out vec4 Out_Color;\n"
"void main()\n"
"{\n"
" Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
"}\n";
const GLchar *fragment_shader_glsl_300_es =
"precision mediump float;\n"
"uniform sampler2D Texture;\n"
"in vec2 Frag_UV;\n"
"in vec4 Frag_Color;\n"
"layout (location = 0) out vec4 Out_Color;\n"
"void main()\n"
"{\n"
" Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
"}\n";
const GLchar *fragment_shader_glsl_410_core =
"in vec2 Frag_UV;\n"
"in vec4 Frag_Color;\n"
"uniform sampler2D Texture;\n"
"layout (location = 0) out vec4 Out_Color;\n"
"void main()\n"
"{\n"
" Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
"}\n";
// Select shaders matching our GLSL versions
const GLchar *vertex_shader = nullptr;
const GLchar *fragment_shader = nullptr;
if (glsl_version < 130) {
vertex_shader = vertex_shader_glsl_120;
fragment_shader = fragment_shader_glsl_120;
} else if (glsl_version >= 410) {
vertex_shader = vertex_shader_glsl_410_core;
fragment_shader = fragment_shader_glsl_410_core;
} else if (glsl_version == 300) {
vertex_shader = vertex_shader_glsl_300_es;
fragment_shader = fragment_shader_glsl_300_es;
} else {
vertex_shader = vertex_shader_glsl_130;
fragment_shader = fragment_shader_glsl_130;
}
// Create shaders
const GLchar *vertex_shader_with_version[2] = {bd->GlslVersionString,
vertex_shader};
GLuint vert_handle = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vert_handle, 2, vertex_shader_with_version, nullptr);
glCompileShader(vert_handle);
CheckShader(vert_handle, "vertex shader");
const GLchar *fragment_shader_with_version[2] = {bd->GlslVersionString,
fragment_shader};
GLuint frag_handle = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(frag_handle, 2, fragment_shader_with_version, nullptr);
glCompileShader(frag_handle);
CheckShader(frag_handle, "fragment shader");
// Link
bd->ShaderHandle = glCreateProgram();
glAttachShader(bd->ShaderHandle, vert_handle);
glAttachShader(bd->ShaderHandle, frag_handle);
glLinkProgram(bd->ShaderHandle);
CheckProgram(bd->ShaderHandle, "shader program");
glDetachShader(bd->ShaderHandle, vert_handle);
glDetachShader(bd->ShaderHandle, frag_handle);
glDeleteShader(vert_handle);
glDeleteShader(frag_handle);
bd->AttribLocationTex = glGetUniformLocation(bd->ShaderHandle, "Texture");
bd->AttribLocationProjMtx = glGetUniformLocation(bd->ShaderHandle, "ProjMtx");
bd->AttribLocationVtxPos =
(GLuint)glGetAttribLocation(bd->ShaderHandle, "Position");
bd->AttribLocationVtxUV = (GLuint)glGetAttribLocation(bd->ShaderHandle, "UV");
bd->AttribLocationVtxColor =
(GLuint)glGetAttribLocation(bd->ShaderHandle, "Color");
// Create buffers
glGenBuffers(1, &bd->VboHandle);
glGenBuffers(1, &bd->ElementsHandle);
ImGui_ImplOpenGL3_CreateFontsTexture();
// Restore modified GL state
glBindTexture(GL_TEXTURE_2D, last_texture);
glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_BUFFER_PIXEL_UNPACK
if (bd->GlVersion >= 210) {
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, last_pixel_unpack_buffer);
}
#endif
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
glBindVertexArray(last_vertex_array);
#endif
return true;
}
void ImGui_ImplOpenGL3_DestroyDeviceObjects() {
ImGui_ImplOpenGL3_Data *bd = ImGui_ImplOpenGL3_GetBackendData();
if (bd->VboHandle) {
glDeleteBuffers(1, &bd->VboHandle);
bd->VboHandle = 0;
}
if (bd->ElementsHandle) {
glDeleteBuffers(1, &bd->ElementsHandle);
bd->ElementsHandle = 0;
}
if (bd->ShaderHandle) {
glDeleteProgram(bd->ShaderHandle);
bd->ShaderHandle = 0;
}
ImGui_ImplOpenGL3_DestroyFontsTexture();
}
//--------------------------------------------------------------------------------------------------------
// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
// This is an _advanced_ and _optional_ feature, allowing the backend to create
// and handle multiple viewports simultaneously. 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..
//--------------------------------------------------------------------------------------------------------
static void ImGui_ImplOpenGL3_RenderWindow(ImGuiViewport *viewport, void *) {
if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear)) {
ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
glClear(GL_COLOR_BUFFER_BIT);
}
ImGui_ImplOpenGL3_RenderDrawData(viewport->DrawData);
}
static void ImGui_ImplOpenGL3_InitPlatformInterface() {
ImGuiPlatformIO &platform_io = ImGui::GetPlatformIO();
platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
}
static void ImGui_ImplOpenGL3_ShutdownPlatformInterface() {
ImGui::DestroyPlatformWindows();
}
//-----------------------------------------------------------------------------
#if defined(__GNUC__)
#pragma GCC diagnostic pop
#endif
#if defined(__clang__)
#pragma clang diagnostic pop
#endif
#endif // #ifndef IMGUI_DISABLE