From 8c02c0636e8cff892651150b90087a2bba245aba Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sun, 11 Oct 2015 16:41:00 -0400
Subject: [PATCH] build with GL3W

---
 Makefile | 22 ++++++++++++++++------
 app.cc   | 40 ++++++++++++++++++----------------------
 2 files changed, 34 insertions(+), 28 deletions(-)

diff --git a/Makefile b/Makefile
index 70b366b..753412f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,22 +1,32 @@
-FILE := app
-TARGET := $(FILE)
+TARGET := app
+OBJS := app.o GL3/gl3w.o
 REPOS := glcxx glm
 
 CCFLAGS := $(shell sdl2-config --cflags)
 ifeq (MINGW,$(findstring MINGW,$(shell uname)))
-LIBS := -lopengl32 -lglu32 -lmingw32
+LIBS := -lopengl32 -lmingw32
 CXX := mingw32-g++
 TARGET := $(TARGET).exe
 else
-LIBS := -lGL -lGLU `sdl2-config --libs`
+LIBS := -lGL `sdl2-config --libs`
 endif
+LIBS += -ldl
 LDFLAGS := $(LIBS) $(shell sdl2-config --libs)
+CCFLAGS += -I glcxx/include -I glm -I.
+CXXFLAGS += -std=gnu++14
+CCFLAGS += -DGLCXX_GL_INCLUDE='"GL3/gl3w.h"'
 
 
 all: submodule_init $(TARGET)
 
-$(TARGET): $(FILE).cc
-	$(CXX) -o $(TARGET) $(CCFLAGS) $< $(LDFLAGS)
+$(TARGET): $(OBJS)
+	$(CXX) -o $(TARGET) $^ $(LDFLAGS)
+
+%.o: %.c
+	$(CC) -c -o $@ $(CCFLAGS) $(CFLAGS) $<
+
+%.o: %.cc
+	$(CXX) -c -o $@ $(CCFLAGS) $(CXXFLAGS) $<
 
 .PHONY: submodule_init
 submodule_init:
diff --git a/app.cc b/app.cc
index 00d1d46..376c25a 100644
--- a/app.cc
+++ b/app.cc
@@ -1,7 +1,12 @@
 #include <SDL.h>
-#include <GL/gl.h>
-#include <GL/glu.h>
 #include <stdio.h>
+#include "glcxx.hpp"
+#include "GL3/gl3w.h"
+#include <iostream>
+
+using namespace std;
+
+std::shared_ptr<glcxx::Program> program;
 
 #define WIDTH   800
 #define HEIGHT  800
@@ -10,32 +15,12 @@ void init(void)
 {
     glClearColor (0.0, 0.0, 0.0, 0.0);
     glEnable(GL_DEPTH_TEST);
-    glShadeModel(GL_FLAT);
     glViewport(0, 0, WIDTH, HEIGHT);
-    glMatrixMode(GL_PROJECTION);
-    glLoadIdentity();
-    glOrtho(-0.5, WIDTH - 0.5, -0.5, HEIGHT - 0.5, -1, 1);
-    glMatrixMode(GL_MODELVIEW);
-    glLoadIdentity();
 }
 
 void display(SDL_Window * window)
 {
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-    glColor3f(1, 1, 1);
-    glBegin(GL_QUADS);
-        glVertex3f(10, HEIGHT / 2, 0.0);
-        glVertex3f(10, 3 * HEIGHT / 4, 0.0);
-        glVertex3f(WIDTH / 2, 3 * HEIGHT / 4, 0.0);
-        glVertex3f(WIDTH / 2, HEIGHT / 2, 0.0);
-    glEnd();
-    glColor3f(1, 0.6, 0);
-    glBegin(GL_LINE_LOOP);
-        glVertex2f(0, 0);
-        glVertex2f(WIDTH - 1, 0);
-        glVertex2f(WIDTH - 1, HEIGHT - 1);
-        glVertex2f(0, HEIGHT - 1);
-    glEnd();
     SDL_GL_SwapWindow(window);
 }
 
@@ -64,6 +49,17 @@ int main(int argc, char *argv[])
 
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
 
+    if (gl3wInit())
+    {
+        cerr << "Failed to initialize GL3W" << endl;
+        return 2;
+    }
+    if (!gl3wIsSupported(3, 0))
+    {
+        cerr << "OpenGL 3.0 is not supported!" << endl;
+        return 2;
+    }
+
     init();
     display(window);
     SDL_Event event;