罗大柚OpenGL ES教程系列LessonTwo（Part 2）：采用VAO绘制一个Cube
前面的创建过程和LessonTwo（part 1）一样， 结果也差不多，这个project和前面相比除了是使用VAO以外，还有就是启动了光照。废话不多说，直接上代码：
#import "ViewController.h"
#defineBUFFER_OFFSET(i) ((char *)NULL + (i))
//这里我们直接用系统中创建OpenGL Game程序时默认的顶点数据
GLfloat gCubeVertexData[216] =
{
// Data layout for each line below is:
// positionX, positionY, positionZ, normalX, normalY, normalZ,
//前面
0.5f, -0.5f, -0.5f, 1.0f,0.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f,0.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f,0.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f,0.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f,0.0f, 0.0f,
//后面
0.5f, 0.5f, -0.5f, 0.0f,1.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 0.0f,1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 0.0f,1.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 0.0f,1.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 0.0f,1.0f, 0.0f,
//左面
-0.5f, 0.5f, -0.5f, -1.0f,0.0f, 0.0f,
-0.5f, -0.5f, -0.5f, -1.0f,0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, -1.0f,0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, -1.0f,0.0f, 0.0f,
-0.5f, -0.5f, -0.5f, -1.0f,0.0f, 0.0f,
-0.5f, -0.5f, 0.5f, -1.0f,0.0f, 0.0f,
//右面
-0.5f, -0.5f, -0.5f, 0.0f,-1.0f, 0.0f,
0.5f, -0.5f, -0.5f, 0.0f,-1.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f,-1.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f,-1.0f, 0.0f,
0.5f, -0.5f, -0.5f, 0.0f,-1.0f, 0.0f,
0.5f, -0.5f, 0.5f, 0.0f,-1.0f, 0.0f,
//下面
0.5f, 0.5f, 0.5f, 0.0f,0.0f, 1.0f,
-0.5f, 0.5f, 0.5f, 0.0f,0.0f, 1.0f,
0.5f, -0.5f, 0.5f, 0.0f,0.0f, 1.0f,
0.5f, -0.5f, 0.5f, 0.0f,0.0f, 1.0f,
-0.5f, 0.5f, 0.5f, 0.0f,0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f,0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f,0.0f, -1.0f,
-0.5f, -0.5f, -0.5f, 0.0f,0.0f, -1.0f,
0.5f, 0.5f, -0.5f, 0.0f,0.0f, -1.0f,
0.5f, 0.5f, -0.5f, 0.0f,0.0f, -1.0f,
-0.5f, -0.5f, -0.5f, 0.0f,0.0f, -1.0f,
-0.5f, 0.5f, -0.5f, 0.0f,0.0f, -1.0f
};
@interface ViewController ()
{
GLKMatrix4 _modelViewProjectionMatrix;
GLKMatrix3 _normalMatrix;
float_rotation;
GLuint _vertexArray;
GLuint _vertexBuffer;
}
@property (strong,nonatomic) EAGLContext *context;
@property (strong,nonatomic) GLKBaseEffect *effect;
- (void)setupGL;
- (void)tearDownGL;
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.context = [[EAGLContextalloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
if (!self.context) {
NSLog(@"Failed to create ES context");
}
GLKView *view = (GLKView *)self.view;
view.context = self.context;
//
view.drawableDepthFormat = GLKViewDrawableDepthFormat24;
[self setupGL];
}
- (void)setupGL
{
[EAGLContext setCurrentContext:self.context];
self.effect = [[GLKBaseEffectalloc] init];
self.effect.light0.enabled =GL_TRUE;
//散射光
self.effect.light0.diffuseColor =GLKVector4Make(1.0f, 0.4f, 0.4f, 1.0f);
//启动深度测试
glEnable(GL_DEPTH_TEST);
//设置VAO
glGenVertexArraysOES(1, &_vertexArray);
glBindVertexArrayOES(_vertexArray);
//绑定顶点buffer
glGenBuffers(1, &_vertexBuffer);
glBindBuffer(GL_ARRAY_BUFFER,_vertexBuffer);
glBufferData(GL_ARRAY_BUFFER,sizeof(gCubeVertexData),gCubeVertexData, GL_STATIC_DRAW);
//启动顶点
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(GLKVertexAttribPosition, 3,GL_FLOAT, GL_FALSE, 24,BUFFER_OFFSET(0));
//启动顶点法线
glEnableVertexAttribArray(GLKVertexAttribNormal);
glVertexAttribPointer(GLKVertexAttribNormal, 3,GL_FLOAT, GL_FALSE, 24,BUFFER_OFFSET(12));
//Bind back to the default state
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArrayOES(0);
}
//tear down 卸载；卸载GL
- (void)tearDownGL
{
[EAGLContext setCurrentContext:self.context];
glDeleteBuffers(1, &_vertexBuffer);
glDeleteVertexArraysOES(1, &_vertexArray);
self.effect =nil;
}
#pragma mark - GLKView and GLKViewController delegatemethods
- (void)update
{
float aspect= fabsf(self.view.bounds.size.width /self.view.bounds.size.height);
GLKMatrix4 projectionMatrix =GLKMatrix4MakePerspective(GLKMathDegreesToRadians(65.0f), aspect, 0.1f, 100.0f);
self.effect.transform.projectionMatrix = projectionMatrix;
GLKMatrix4 modelViewMatrix =GLKMatrix4MakeTranslation(0.0f, 0.0f, -4.5f);
modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix,_rotation, 1.0f, 1.0f, 1.0f);
self.effect.transform.modelviewMatrix = modelViewMatrix;
_normalMatrix = GLKMatrix3InvertAndTranspose(GLKMatrix4GetMatrix3(modelViewMatrix),NULL);
_rotation += self.timeSinceLastUpdate * 0.5f;
}
- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect
{
glClearColor(0.65f, 0.65f, 0.65f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT |GL_DEPTH_BUFFER_BIT);
glBindVertexArrayOES(_vertexArray);
// Render the object with GLKit
[self.effectprepareToDraw];
//画立方体
glDrawArrays(GL_TRIANGLES, 0, 36);
}
- (void)dealloc
{
[self tearDownGL];
if ([EAGLContextcurrentContext] == self.context) {
[EAGLContext setCurrentContext:nil];
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
if ([selfisViewLoaded] && ([[selfview] window] ==nil)) {
self.view =nil;
[self tearDownGL];
if ([EAGLContextcurrentContext] == self.context) {
[EAGLContext setCurrentContext:nil];
}
self.context =nil;
}
}
@end
源码下载：http://download.csdn.net/detail/luozhonglan/6987129