Examples: OpenGL: Added a dummy GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early, and help users understand what they are missing. (#2421)

This commit is contained in:
omar
2019-03-15 13:09:07 +01:00
parent cf2c52282d
commit ff03ae503b
3 changed files with 15 additions and 6 deletions

View File

@ -12,6 +12,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2019-03-15: OpenGL: Added a dummy 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.
@ -89,11 +90,11 @@
// 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>
#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>
#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>
#include <glad/glad.h> // Needs to be initialized with gladLoadGL() in user's code
#else
#include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
#endif
@ -128,6 +129,12 @@ bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
strcpy(g_GlslVersionString, glsl_version);
strcat(g_GlslVersionString, "\n");
// Make a dummy 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.
GLint current_texture;
glGetIntegerv(GL_TEXTURE_BINDING_2D, &current_texture);
return true;
}