added triangle

OpenGL1.pro

@@ -3,3 +3,4 @@ TARGET=OpenGL1
 SOURCES += main.cpp
 QMAKE_CXXFLAGS += $$system(sdl2-config --cflags)
 LIBS+= $$system(sdl2-config --libs)
+LIBS+= -lGLU

main.cpp

@@ -1,6 +1,11 @@
 #include <iostream>
 #include <SDL.h>
+#include <GL/gl.h>
+#include <GL/glu.h>
 #include <cstdlib>
+
+void drawTriangle();
+
 int main()
 {
   if(SDL_Init(SDL_INIT_VIDEO))
@@ -23,6 +28,48 @@ int main()
 
         );
 
+  SDL_GLContext glContext;
+  // set OpenGL attributes
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION,2);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION,0);
+  SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE,16);
+  SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER,1);
+  glContext=SDL_GL_CreateContext(window);
+  // now make this the active context
+  SDL_GL_MakeCurrent(window,glContext);
+  glClearColor(1.0,1.0,1.0,1.0);
+  glClear(GL_COLOR_BUFFER_BIT);
+  glMatrixMode(GL_PROJECTION);
+  gluPerspective(45.0f,(float)screenSize.w/screenSize.h,
+                 0.5,100
+                 );
+
+  glMatrixMode(GL_MODELVIEW);
+  gluLookAt(2,2,2,0,0,0,0,1,0);
+
+  drawTriangle();
+  SDL_GL_SwapWindow(window);
   SDL_Delay(10000);
 
 }
+
+void drawTriangle()
+{
+  glPushMatrix();
+    glBegin(GL_TRIANGLES);
+      glColor3f(1.0f,0.0,0.0f);
+      glVertex3f(0.0f,1.0f,0.0f);
+      glColor3f(0.0f,1.0f,0.0f);
+      glVertex3f(1.0f,-1.0f,0.0f);
+      glColor3f(0.0f,0.0f,1.0f);
+      glVertex3f(-1.0f,-1.0f,0.0f);
+    glEnd();
+  glPopMatrix();
+}
+
+
+
+
+
+
+