Pro OpenGL ES for iOS

18 CHAPTER 1: Computer Graphics: From Then to Now^

• (void)setupGL
  {
  [EAGLContext setCurrentContext:self.context]; //7

[self loadShaders];

self.effect = [[GLKBaseEffect alloc] init]; //8

self.effect.light0.enabled = GL_TRUE; //9

self.effect.light0.diffuseColor = GLKVector4Make(1.0f, 0.4f, 0.4f, 1.0f); //10

glEnable(GL_DEPTH_TEST); //11

glGenVertexArraysOES(1, &_vertexArray); //12

glBindVertexArrayOES(_vertexArray);

glGenBuffers(1, &_vertexBuffer); //13

glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer);

glBufferData(GL_ARRAY_BUFFER,

sizeof(gCubeVertexData), gCubeVertexData, GL_STATIC_DRAW); //14

glEnableVertexAttribArray(GLKVertexAttribPosition); //15

glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 24,

BUFFER_OFFSET(0));

glEnableVertexAttribArray(GLKVertexAttribNormal);

glVertexAttribPointer(GLKVertexAttribNormal, 3, GL_FLOAT, GL_FALSE, 24,

BUFFER_OFFSET(12));

glBindVertexArrayOES(0); //16

}

• (void)tearDownGL //17
  {
  [EAGLContext setCurrentContext:self.context];

glDeleteBuffers(1, &_vertexBuffer);

glDeleteVertexArraysOES(1, &_vertexArray);

self.effect = nil;

if (_program) {

glDeleteProgram(_program);

_program = 0;

}

}