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Use own embedded OpenGL loader #3

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Use own embedded OpenGL loader #3

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81 changes: 21 additions & 60 deletions backends/tex_inspect_opengl.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,7 @@
// Search for "END COPIED" to find the end of the copied segment.
// ===========================================================================

// COPIED FROM imgui_impl_opengl3.cp ////////////////////////////////////////
// COPIED FROM imgui_impl_opengl3.cpp ////////////////////////////////////////
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif
Expand All @@ -47,38 +47,16 @@
#else
#include <GLES3/gl3.h> // Use GL ES 3
#endif
#else
// About Desktop OpenGL function loaders:
// 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 supporting a few common ones (gl3w, glew, glad).
// You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.
#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
#include <GL/gl3w.h> // Needs to be initialized with gl3wInit() in user's code
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
#include <GL/glew.h> // Needs to be initialized with glewInit() in user's code.
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
#include <glad/glad.h> // Needs to be initialized with gladLoadGL() in user's code.
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
#include <glad/gl.h> // Needs to be initialized with gladLoadGL(...) or gladLoaderLoadGL() in user's code.
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
#ifndef GLFW_INCLUDE_NONE
#define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
#endif
#include <glbinding/Binding.h> // Needs to be initialized with glbinding::Binding::initialize() in user's code.
#include <glbinding/gl/gl.h>
using namespace gl;
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
#ifndef GLFW_INCLUDE_NONE
#define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
#endif
#include <glbinding/glbinding.h>// Needs to be initialized with glbinding::initialize() in user's code.
#include <glbinding/gl/gl.h>
using namespace gl;
#elif defined(IMGUI_IMPL_OPENGL_LOADER_EPOXY)
#include <epoxy/gl.h>
#else
#include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
#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 IMTEXIN_GL3W_IMPL
#include "tex_inspect_opengl_loader.h"
#endif

// Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't have.
Expand Down Expand Up @@ -110,6 +88,15 @@ static GLint g_UniformLocationGridWidth = 0;
// Functions
static bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
{
// Initialize our loader
#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
if (imtexin_gl3wInit() != 0)
{
fprintf(stderr, "Failed to initialize OpenGL loader!\n");
return false;
}
#endif

// Query for GL version (e.g. 320 for GL 3.2)
#if !defined(IMGUI_IMPL_OPENGL_ES2)
GLint major = 0;
Expand Down Expand Up @@ -147,34 +134,8 @@ static bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
strcpy(g_GlslVersionString, glsl_version);
strcat(g_GlslVersionString, "\n");

// Debugging construct to make it easily visible in the IDE and debugger which GL loader has been selected.
// The code actually never uses the 'gl_loader' variable! It is only here so you can read it!
// If auto-detection fails or doesn't select the same GL loader file as used by your application,
// you are likely to get a crash below.
// You can explicitly select a loader by using '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
const char* gl_loader = "Unknown";
IM_UNUSED(gl_loader);
#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
gl_loader = "GL3W";
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
gl_loader = "GLEW";
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
gl_loader = "GLAD";
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
gl_loader = "GLAD2";
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
gl_loader = "glbinding2";
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
gl_loader = "glbinding3";
#elif defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
gl_loader = "custom";
#else
gl_loader = "none";
#endif

// Make an arbitrary GL call (we don't actually need the result)
// IF YOU GET A CRASH HERE: it probably means that you haven't initialized the OpenGL function loader used by this code.
// Desktop OpenGL 3/4 need a function loader. See the IMGUI_IMPL_OPENGL_LOADER_xxx explanation above.
// 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, &current_texture);

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