Examples: OpenGL: Added support for glew and glad OpenGL loaders out of the box. (#2001, #2002). Changelog, tweaks, applied changes to SDL+OpenGL3 example.
diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 6a1b432..b92407c 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -104,6 +104,7 @@
- Examples: OpenGL3: Tweaked the imgui_impl_opengl3.cpp to work as-is with Emscripten + WebGL 2.0. (#1941). [@o-micron]
- Examples: OpenGL3: Made the example app default to GL 3.0 + GLSL 130 (instead of GL 3.2 + GLSL 150) unless on Mac.
- Examples: OpenGL3: Added error output when shaders fail to compile/link.
+ - Examples: OpenGL3: Added support for glew and glad OpenGL loaders out of the box. (#2001, #2002) [@jdumas]
- Examples: OpenGL2: Disabling/restoring GL_LIGHTING and GL_COLOR_MATERIAL to increase compatibility with legacy OpenGL applications. (#1996)
- Examples: DirectX10, DirectX11: Fixed unreleased resources in Init and Shutdown functions. (#1944)
- Examples: DirectX11: Querying for IDXGIFactory instead of IDXGIFactory1 to increase compatibility. (#1989) [@matt77hias]
diff --git a/examples/example_glfw_opengl3/Makefile b/examples/example_glfw_opengl3/Makefile
index 3f5a372..d36b78d 100644
--- a/examples/example_glfw_opengl3/Makefile
+++ b/examples/example_glfw_opengl3/Makefile
@@ -19,21 +19,28 @@
SOURCES += ../imgui_impl_glfw.cpp ../imgui_impl_opengl3.cpp
SOURCES += ../../imgui.cpp ../../imgui_demo.cpp ../../imgui_draw.cpp
OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
-
UNAME_S := $(shell uname -s)
-# Default OpenGL loader: gl3w
+##---------------------------------------------------------------------
+## OPENGL LOADER
+##---------------------------------------------------------------------
+
+## Using OpenGL loader: gl3w [default]
SOURCES += ../libs/gl3w/GL/gl3w.c
CXXFLAGS = -I../libs/gl3w
-# You can switch to glad by changing the following compilation options,
-# and changing the rule L73 of this Makefile
+## Using OpenGL loader: glew
+## (This assumes a system-wide installation)
+# CXXFLAGS = -lGLEW -DIMGUI_IMPL_OPENGL_LOADER_GLEW
+
+## Using OpenGL loader: glad
+## (You'll also need to change the rule at line ~77 of this Makefile to compile/link glad.c/.o)
# SOURCES += ../libs/glad/src/glad.c
# CXXFLAGS = -I../libs/glad/include -DIMGUI_IMPL_OPENGL_LOADER_GLAD
-# You can also use glew are you OpenGL loader
-# This assumes a system-wide installation
-# CXXFLAGS = -lGLEW -DIMGUI_IMPL_OPENGL_LOADER_GLEW
+##---------------------------------------------------------------------
+## BUILD FLAGS PER PLATFORM
+##---------------------------------------------------------------------
ifeq ($(UNAME_S), Linux) #LINUX
ECHO_MESSAGE = "Linux"
@@ -64,6 +71,9 @@
CFLAGS = $(CXXFLAGS)
endif
+##---------------------------------------------------------------------
+## BUILD RULES
+##---------------------------------------------------------------------
%.o:%.cpp
$(CXX) $(CXXFLAGS) -c -o $@ $<
diff --git a/examples/example_glfw_opengl3/main.cpp b/examples/example_glfw_opengl3/main.cpp
index d99ec3b..2795ff4 100644
--- a/examples/example_glfw_opengl3/main.cpp
+++ b/examples/example_glfw_opengl3/main.cpp
@@ -1,22 +1,23 @@
// ImGui - standalone example application for GLFW + OpenGL 3, using programmable pipeline
// If you are new to ImGui, see examples/README.txt and documentation at the top of imgui.cpp.
// (GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
-// (GL3W is a helper library to access OpenGL functions since there is no standard header to access modern OpenGL functions easily. Alternatives are GLEW, Glad, etc.)
#include "imgui.h"
#include "imgui_impl_glfw.h"
#include "imgui_impl_opengl3.h"
#include <stdio.h>
-// This example is using gl3w to access OpenGL functions. You may use another OpenGL loader/header such as: glew, glext, glad, glLoadGen, etc.
+// About OpenGL function loaders: modern OpenGL doesn't have a standard header file and requires individual function pointers to be loaded manually.
+// 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> // Initialize with gl3wInit()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
-#include <GL/glew.h>
+#include <GL/glew.h> // Initialize with glewInit()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
-#include <glad/glad.h>
+#include <glad/glad.h> // Initialize with gladLoadGL()
#else
-#pragma error("Cannot use custom loader for example application.")
+#include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
#endif
#include <GLFW/glfw3.h> // Include glfw3.h after our OpenGL definitions
@@ -56,17 +57,18 @@
return 1;
glfwMakeContextCurrent(window);
glfwSwapInterval(1); // Enable vsync
+
+ // Initialize OpenGL loader
#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
- GLenum err = gl3wInit();
- if (!err) {
+ bool err = gl3wInit() != 0;
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
- GLenum err = glewInit();
- if (GLEW_OK != err) {
+ bool err = glewInit() != GLEW_OK;
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
- GLenum err = gladLoadGL();
- if (!err) {
+ bool err = gladLoadGL() != 0;
#endif
- fprintf(stderr, "Failed to initialize OpenGL\n");
+ if (err)
+ {
+ fprintf(stderr, "Failed to initialize OpenGL loader!\n");
return 1;
}
diff --git a/examples/example_sdl_opengl3/Makefile b/examples/example_sdl_opengl3/Makefile
index fb826cb..765c446 100644
--- a/examples/example_sdl_opengl3/Makefile
+++ b/examples/example_sdl_opengl3/Makefile
@@ -18,11 +18,29 @@
SOURCES = main.cpp
SOURCES += ../imgui_impl_sdl.cpp ../imgui_impl_opengl3.cpp
SOURCES += ../../imgui.cpp ../../imgui_demo.cpp ../../imgui_draw.cpp
-SOURCES += ../libs/gl3w/GL/gl3w.c
OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
-
UNAME_S := $(shell uname -s)
+##---------------------------------------------------------------------
+## OPENGL LOADER
+##---------------------------------------------------------------------
+
+## Using OpenGL loader: gl3w [default]
+SOURCES += ../libs/gl3w/GL/gl3w.c
+CXXFLAGS = -I../libs/gl3w
+
+## Using OpenGL loader: glew
+## (This assumes a system-wide installation)
+# CXXFLAGS = -lGLEW -DIMGUI_IMPL_OPENGL_LOADER_GLEW
+
+## Using OpenGL loader: glad
+## (You'll also need to change the rule at line ~77 of this Makefile to compile/link glad.c/.o)
+# SOURCES += ../libs/glad/src/glad.c
+# CXXFLAGS = -I../libs/glad/include -DIMGUI_IMPL_OPENGL_LOADER_GLAD
+
+##---------------------------------------------------------------------
+## BUILD FLAGS PER PLATFORM
+##---------------------------------------------------------------------
ifeq ($(UNAME_S), Linux) #LINUX
ECHO_MESSAGE = "Linux"
@@ -51,6 +69,9 @@
CFLAGS = $(CXXFLAGS)
endif
+##---------------------------------------------------------------------
+## BUILD RULES
+##---------------------------------------------------------------------
%.o:%.cpp
$(CXX) $(CXXFLAGS) -c -o $@ $<
diff --git a/examples/example_sdl_opengl3/main.cpp b/examples/example_sdl_opengl3/main.cpp
index 24b25cc..bdd8a9a 100644
--- a/examples/example_sdl_opengl3/main.cpp
+++ b/examples/example_sdl_opengl3/main.cpp
@@ -9,10 +9,18 @@
#include <stdio.h>
#include <SDL.h>
-#include <GL/gl3w.h> // This example is using gl3w to access OpenGL functions. You may use another OpenGL loader/header such as: glew, glext, glad, glLoadGen, etc.
-//#include <glew.h>
-//#include <glext.h>
-//#include <glad/glad.h>
+// About OpenGL function loaders: modern OpenGL doesn't have a standard header file and requires individual function pointers to be loaded manually.
+// 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> // Initialize with gl3wInit()
+#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
+#include <GL/glew.h> // Initialize with glewInit()
+#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
+#include <glad/glad.h> // Initialize with gladLoadGL()
+#else
+#include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
+#endif
int main(int, char**)
{
@@ -49,7 +57,20 @@
SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
SDL_GLContext gl_context = SDL_GL_CreateContext(window);
SDL_GL_SetSwapInterval(1); // Enable vsync
- gl3wInit();
+
+ // Initialize OpenGL loader
+#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
+ bool err = gl3wInit() != 0;
+#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
+ bool err = glewInit() != GLEW_OK;
+#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
+ bool err = gladLoadGL() != 0;
+#endif
+ if (err)
+ {
+ fprintf(stderr, "Failed to initialize OpenGL loader!\n");
+ return 1;
+ }
// Setup Dear ImGui binding
IMGUI_CHECKVERSION();
diff --git a/examples/imgui_impl_opengl3.cpp b/examples/imgui_impl_opengl3.cpp
index 16a9eb4..73fa3da 100644
--- a/examples/imgui_impl_opengl3.cpp
+++ b/examples/imgui_impl_opengl3.cpp
@@ -11,6 +11,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
+// 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.
@@ -72,18 +73,16 @@
// OpenGL ES 3
#include <GLES3/gl3.h> // Use GL ES 3
#else
-// OpenGL Regular
-// (About OpenGL function loaders: modern OpenGL doesn't have a standard header file and requires individual functions to be loaded manually.
-// Helper libraries are often used for this purpose! Here we are using gl3w.h, which requires a call to gl3wInit().
-// You may use another any other loader/header of your choice, such as glew, glext, glad, glLoadGen, etc.)
+// Regular OpenGL
+// About OpenGL function loaders: modern OpenGL doesn't have a standard header file and requires individual function pointers to be loaded manually.
+// 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>
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
#include <GL/glew.h>
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
#include <glad/glad.h>
-#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEXT)
-#include <glext.h>
#else
#include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
#endif
diff --git a/examples/imgui_impl_opengl3.h b/examples/imgui_impl_opengl3.h
index b5e93b0..2812dac 100644
--- a/examples/imgui_impl_opengl3.h
+++ b/examples/imgui_impl_opengl3.h
@@ -9,10 +9,10 @@
// If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
// https://github.com/ocornut/imgui
-// About OpenGL function loaders:
-// Modern OpenGL requires individual functions to be loaded manually. Helper libraries are often used for this purpose.
-// Here we are using gl3w.h, which requires a call to gl3wInit().
-// You may use another any other loader/header of your choice, such as glew, glext, glad, glLoadGen, etc.
+// About OpenGL function loaders:
+// About OpenGL function loaders: modern OpenGL doesn't have a standard header file and requires individual function pointers to be loaded manually.
+// 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.
// About GLSL version:
// The 'glsl_version' initialization parameter should be NULL (default) or a "#version XXX" string.
@@ -20,10 +20,10 @@
// Only override if your GL version doesn't handle this GLSL version. See GLSL version table at the top of imgui_impl_opengl3.cpp.
// Set default OpenGL loader to be gl3w
-#if !defined(IMGUI_IMPL_OPENGL_LOADER_GL3W) \
- && !defined(IMGUI_IMPL_OPENGL_LOADER_GLEW) \
- && !defined(IMGUI_IMPL_OPENGL_LOADER_GLAD) \
- && !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
+#if !defined(IMGUI_IMPL_OPENGL_LOADER_GL3W) \
+ && !defined(IMGUI_IMPL_OPENGL_LOADER_GLEW) \
+ && !defined(IMGUI_IMPL_OPENGL_LOADER_GLAD) \
+ && !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
#define IMGUI_IMPL_OPENGL_LOADER_GL3W
#endif
