五：GLKit图片&颜色混合

效果图如下：

纹理&颜色混合.png

核心代码如下：

#import "CCViewController.h"

@interface CCViewController()

@property(nonatomic,strong)EAGLContext *mContext;
@property(nonatomic,strong)GLKBaseEffect *mEffect;

@property(nonatomic,assign)int count;

//旋转的度数
@property(nonatomic,assign)float XDegree;
@property(nonatomic,assign)float YDegree;
@property(nonatomic,assign)float ZDegree;

//是否旋转X,Y,Z
@property(nonatomic,assign) BOOL XB;
@property(nonatomic,assign) BOOL YB;
@property(nonatomic,assign) BOOL ZB;

@end

@implementation CCViewController
{
    dispatch_source_t timer;
}
-(void)viewDidLoad
{
    [super viewDidLoad];
    
    //1.新建图层
    [self setupContext];
    
    //2.渲染图形
    [self render];
}

//2.渲染图形
-(void)render
{
    //1.
//    GLfloat attrArr[] =
//    {
//        -0.5f, 0.5f, 0.0f,      1.0f, 0.0f, 1.0f, //左上
//        0.5f, 0.5f, 0.0f,       1.0f, 0.0f, 1.0f, //右上
//        -0.5f, -0.5f, 0.0f,     1.0f, 1.0f, 1.0f, //左下
//
//        0.5f, -0.5f, 0.0f,      1.0f, 1.0f, 1.0f, //右下
//        0.0f, 0.0f, 1.0f,       0.0f, 1.0f, 0.0f, //顶点
//    };
    
        GLfloat attrArr[] =
        {
            -0.5f, 0.5f, 0.0f,      1.0f, 0.0f, 1.0f,       0.0f, 1.0f,//左上
            0.5f, 0.5f, 0.0f,       1.0f, 0.0f, 1.0f,       1.0f, 1.0f,//右上
            -0.5f, -0.5f, 0.0f,     1.0f, 1.0f, 1.0f,       0.0f, 0.0f,//左下
    
            0.5f, -0.5f, 0.0f,      1.0f, 1.0f, 1.0f,       1.0f, 0.0f,//右下
            0.0f, 0.0f, 1.0f,       0.0f, 1.0f, 0.0f,       0.5f, 0.5f,//顶点
        };
    
    //2.绘图索引
    GLuint indices[] =
    {
        0, 3, 2,
        0, 1, 3,
        0, 2, 4,
        0, 4, 1,
        2, 3, 4,
        1, 4, 3,
    };
    self.count = sizeof(indices)/sizeof(GLuint);
    
    GLuint buffer;
    glGenBuffers(1, &buffer);
    glBindBuffer(GL_ARRAY_BUFFER, buffer);
    glBufferData(GL_ARRAY_BUFFER, sizeof(attrArr), attrArr, GL_DYNAMIC_DRAW);
    
    GLuint index;
    glGenBuffers(1, &index);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, index);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_DYNAMIC_DRAW);
    
    glEnableVertexAttribArray(GLKVertexAttribPosition);
    glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat)*8, NULL);
    
    glEnableVertexAttribArray(GLKVertexAttribColor);
    glVertexAttribPointer(GLKVertexAttribColor, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat)*8, (GLfloat *)NULL+3);
    
    glEnableVertexAttribArray(GLKVertexAttribTexCoord0);
    glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat)*8, (GLfloat *)NULL+6);
    
    //纹理加载.
    NSString *filePath = [[NSBundle mainBundle]pathForResource:@"kunkun" ofType:@"jpg"];
    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:@"1",GLKTextureLoaderOriginBottomLeft, nil];
    GLKTextureInfo *textureInfo = [GLKTextureLoader textureWithContentsOfFile:filePath options:options error:nil];
    
    self.mEffect = [[GLKBaseEffect alloc]init];
    self.mEffect.texture2d0.enabled = GL_TRUE;
    self.mEffect.texture2d0.name = textureInfo.name;
    
    CGSize size = self.view.bounds.size;
    float aspect = fabs(size.width/size.height);
    GLKMatrix4 projectionMatrix  = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(90.0), aspect, 0.1, 100.0f);
    self.mEffect.transform.projectionMatrix = projectionMatrix;
   
    GLKMatrix4 modelViewMatrix = GLKMatrix4Translate(GLKMatrix4Identity, 0, 0, -2);
    self.mEffect.transform.modelviewMatrix = modelViewMatrix;
    
    //定时器: -> GCD
    double seconds = 0.1;
    timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, dispatch_get_main_queue());
    dispatch_source_set_timer(timer, DISPATCH_TIME_NOW, seconds * NSEC_PER_SEC, 0.0);
    dispatch_source_set_event_handler(timer, ^{
        
        self.XDegree += 0.1f * self.XB;
        self.YDegree += 0.1f * self.YB;
        self.ZDegree += 0.1f * self.ZB ;
        
    });
    dispatch_resume(timer);

}

//场景数据变化
-(void)update
{
    GLKMatrix4 modelViewMatrix = GLKMatrix4Translate(GLKMatrix4Identity, 0, 0, -2.5);
    
    modelViewMatrix = GLKMatrix4RotateX(modelViewMatrix, self.XDegree);
    modelViewMatrix = GLKMatrix4RotateY(modelViewMatrix, self.YDegree);
    modelViewMatrix = GLKMatrix4RotateZ(modelViewMatrix, self.ZDegree);
    
    self.mEffect.transform.modelviewMatrix = modelViewMatrix;
}

- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect {
 
    glClearColor(0.3, 0.3, 0.3, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    [self.mEffect prepareToDraw];
    glDrawElements(GL_TRIANGLES, self.count,GL_UNSIGNED_INT, 0);
    
}

//1.新建图层
-(void)setupContext
{
    //1.
    self.mContext = [[EAGLContext alloc]initWithAPI:kEAGLRenderingAPIOpenGLES2];
    
    //2.
    GLKView *view = (GLKView *)self.view;
    view.context = self.mContext;
    view.drawableColorFormat = GLKViewDrawableColorFormatRGBA8888;
    view.drawableDepthFormat = GLKViewDrawableDepthFormat24;
    
    [EAGLContext setCurrentContext:self.mContext];
    
    //3.
    glEnable(GL_DEPTH_TEST);
    
}

#pragma mark -XYZClick
- (IBAction)XClick:(id)sender {
    _XB = !_XB;
}
- (IBAction)YClick:(id)sender {
    _YB = !_YB;
}
- (IBAction)ZClick:(id)sender {
    _ZB = !_ZB;
}


@end