WIP on configurable OpenGL loader. (#2001, #2002)
diff --git a/examples/example_glfw_opengl3/Makefile b/examples/example_glfw_opengl3/Makefile
index 8cfc9f3..3f5a372 100644
--- a/examples/example_glfw_opengl3/Makefile
+++ b/examples/example_glfw_opengl3/Makefile
@@ -18,17 +18,28 @@
SOURCES = main.cpp
SOURCES += ../imgui_impl_glfw.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 := $(shell uname -s)
+# Default OpenGL loader: gl3w
+SOURCES += ../libs/gl3w/GL/gl3w.c
+CXXFLAGS = -I../libs/gl3w
+
+# You can switch to glad by changing the following compilation options,
+# and changing the rule L73 of this Makefile
+# SOURCES += ../libs/glad/src/glad.c
+# CXXFLAGS = -I../libs/glad/include -DIMGUI_IMPL_OPENGL_LOADER_GLAD
+
+# You can also use glew are you OpenGL loader
+# This assumes a system-wide installation
+# CXXFLAGS = -lGLEW -DIMGUI_IMPL_OPENGL_LOADER_GLEW
ifeq ($(UNAME_S), Linux) #LINUX
ECHO_MESSAGE = "Linux"
LIBS = -lGL `pkg-config --static --libs glfw3`
- CXXFLAGS = -I../ -I../../ -I../libs/gl3w `pkg-config --cflags glfw3`
+ CXXFLAGS += -I../ -I../../ `pkg-config --cflags glfw3`
CXXFLAGS += -Wall -Wformat
CFLAGS = $(CXXFLAGS)
endif
@@ -39,7 +50,7 @@
#LIBS += -L/usr/local/lib -lglfw3
LIBS += -L/usr/local/lib -lglfw
- CXXFLAGS = -I../ -I../../ -I../libs/gl3w -I/usr/local/include
+ CXXFLAGS += -I../ -I../../ -I/usr/local/include
CXXFLAGS += -Wall -Wformat
CFLAGS = $(CXXFLAGS)
endif
@@ -48,7 +59,7 @@
ECHO_MESSAGE = "Windows"
LIBS = -lglfw3 -lgdi32 -lopengl32 -limm32
- CXXFLAGS = -I../ -I../../ -I../libs/gl3w `pkg-config --cflags glfw3`
+ CXXFLAGS += -I../ -I../../ `pkg-config --cflags glfw3`
CXXFLAGS += -Wall -Wformat
CFLAGS = $(CXXFLAGS)
endif
@@ -64,6 +75,7 @@
$(CXX) $(CXXFLAGS) -c -o $@ $<
%.o:../libs/gl3w/GL/%.c
+# %.o:../libs/glad/src/%.c
$(CC) $(CFLAGS) -c -o $@ $<
all: $(EXE)
diff --git a/examples/example_glfw_opengl3/main.cpp b/examples/example_glfw_opengl3/main.cpp
index 1ed377c..d99ec3b 100644
--- a/examples/example_glfw_opengl3/main.cpp
+++ b/examples/example_glfw_opengl3/main.cpp
@@ -8,10 +8,16 @@
#include "imgui_impl_opengl3.h"
#include <stdio.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>
+// This example is using gl3w to access OpenGL functions. You may use another OpenGL loader/header such as: glew, glext, glad, glLoadGen, etc.
+#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>
+#else
+#pragma error("Cannot use custom loader for example application.")
+#endif
#include <GLFW/glfw3.h> // Include glfw3.h after our OpenGL definitions
@@ -50,7 +56,19 @@
return 1;
glfwMakeContextCurrent(window);
glfwSwapInterval(1); // Enable vsync
- gl3wInit();
+#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
+ GLenum err = gl3wInit();
+ if (!err) {
+#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
+ GLenum err = glewInit();
+ if (GLEW_OK != err) {
+#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
+ GLenum err = gladLoadGL();
+ if (!err) {
+#endif
+ fprintf(stderr, "Failed to initialize OpenGL\n");
+ return 1;
+ }
// Setup Dear ImGui binding
IMGUI_CHECKVERSION();
@@ -67,8 +85,8 @@
//ImGui::StyleColorsClassic();
// Load Fonts
- // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
- // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
+ // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
+ // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
// - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
// - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
// - Read 'misc/fonts/README.txt' for more instructions and details.
@@ -115,7 +133,7 @@
ImGui::Checkbox("Demo Window", &show_demo_window); // Edit bools storing our window open/close state
ImGui::Checkbox("Another Window", &show_another_window);
- ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f
+ ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f
ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated)
@@ -146,7 +164,7 @@
glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
glClear(GL_COLOR_BUFFER_BIT);
ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
-
+
glfwMakeContextCurrent(window);
glfwSwapBuffers(window);
}
diff --git a/examples/imgui_impl_opengl3.cpp b/examples/imgui_impl_opengl3.cpp
index 5f7095c..16a9eb4 100644
--- a/examples/imgui_impl_opengl3.cpp
+++ b/examples/imgui_impl_opengl3.cpp
@@ -9,7 +9,7 @@
// 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
-// CHANGELOG
+// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 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.
@@ -76,10 +76,17 @@
// (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.)
+#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
#include <GL/gl3w.h>
-//#include <glew.h>
-//#include <glext.h>
-//#include <glad/glad.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
#endif
// OpenGL Data
@@ -120,7 +127,7 @@
// OpenGL3 Render function.
// (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
-// 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.
+// 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.
void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
{
// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
@@ -136,7 +143,9 @@
glActiveTexture(GL_TEXTURE0);
GLint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
+#ifdef GL_SAMPLER_BINDING
GLint last_sampler; glGetIntegerv(GL_SAMPLER_BINDING, &last_sampler);
+#endif
GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
GLint last_vertex_array; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
#ifdef GL_POLYGON_MODE
@@ -186,7 +195,7 @@
#ifdef GL_SAMPLER_BINDING
glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
#endif
- // Recreate the VAO every time
+ // Recreate the VAO every time
// (This is to easily allow multiple GL contexts. VAO are not shared among GL contexts, and we don't track creation/deletion of windows so we don't have an obvious key to use to cache them.)
GLuint vao_handle = 0;
glGenVertexArrays(1, &vao_handle);
diff --git a/examples/imgui_impl_opengl3.h b/examples/imgui_impl_opengl3.h
index 8593b9f..b5e93b0 100644
--- a/examples/imgui_impl_opengl3.h
+++ b/examples/imgui_impl_opengl3.h
@@ -11,7 +11,7 @@
// 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().
+// 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 GLSL version:
@@ -19,6 +19,14 @@
// On computer platform the GLSL version default to "#version 130". On OpenGL ES 3 platform it defaults to "#version 300 es"
// 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)
+#define IMGUI_IMPL_OPENGL_LOADER_GL3W
+#endif
+
IMGUI_IMPL_API bool ImGui_ImplOpenGL3_Init(const char* glsl_version = NULL);
IMGUI_IMPL_API void ImGui_ImplOpenGL3_Shutdown();
IMGUI_IMPL_API void ImGui_ImplOpenGL3_NewFrame();
