我们上一篇中介绍了GLSL索引绘图+颜色纹理混合，那么今天来看一下GLKit索引绘图+颜色纹理混合。整体来说，比GLSL要简单多了 （ps：里面加了是否混合的开关）
准备工作请看案例-GLKit加载图片
一、效果图
image
二、流程图
image
三、代码部分
很简单，就不一一赘述了。
#import "ViewController.h"
@interface ViewController ()
@property (nonatomic,strong) GLKView *glkView;
//着色器程序
@property (nonatomic,strong) GLKBaseEffect *myEffect;
//记录索引数组的个数
@property (nonatomic,assign) int ArrCount;
//记录旋转的角度
@property (nonatomic,assign) float XDegree;
@property (nonatomic,assign) float YDegree;
@property (nonatomic,assign) float ZDegree;
//记录是否开启旋转
@property (nonatomic,assign) BOOL XB;
@property (nonatomic,assign) BOOL YB;
@property (nonatomic,assign) BOOL ZB;
//是否开启纹理颜色混合
@property (nonatomic,assign) BOOL isHybrid;
@end
@implementation ViewController
{
dispatch_source_t timer;
}
- (void)viewDidLoad {
[super viewDidLoad];
self.isHybrid = NO;
/*
思路：
1、初始化配置：
1）context&当前上下文
2）设置glkview
3）开启深度测试
2、设置数据
1）初始化 顶点数据、索引数据
2）把数据copy到缓冲区
3）打开通道，读取需要传递的数据
3、绘制
1）初始化着色器effect
2）是否加载纹理数据
3）投影矩阵
4）视图模型矩阵
4、添加底部buttons
5、开启定时器
*/
//1、
[self SetUpConfig];
//2、
[self SetUpVertexData];
//3、
[self drawPart];
//4、
[self setUpBottomButtons];
//5
[self addTimer];
}
#pragma mark - 1、初始化配置
-(void)SetUpConfig{
//1、创建上下文
EAGLContext *context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
//2、设置当前上下文
[EAGLContext setCurrentContext:context];
//3、
self.glkView = (GLKView *)self.view;
self.glkView.context = context;
self.glkView.drawableColorFormat = GLKViewDrawableColorFormatRGBA8888;
self.glkView.drawableDepthFormat = GLKViewDrawableDepthFormat24;
//4、
glEnable(GL_DEPTH_TEST);
}
#pragma mark - 2、设置数据
-(void)SetUpVertexData{
//1.顶点数据
//前3个元素，是顶点数据；中间3个元素，是顶点颜色值，最后2个是纹理坐标
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
};
//索引数组
GLuint indices[] =
{
0, 3, 2,
0, 1, 3,
0, 2, 4,
0, 4, 1,
2, 3, 4,
1, 4, 3,
};
//索引顶点个数
self.ArrCount = sizeof(indices) / sizeof(GLuint);
//2、把数据分别copy到缓冲区
//顶点缓冲区
GLuint vBuffer;
glGenBuffers(1, &vBuffer);
glBindBuffer(GL_ARRAY_BUFFER, vBuffer);
//拷贝数据
glBufferData(GL_ARRAY_BUFFER, sizeof(attrArr), attrArr, GL_STATIC_DRAW);
//索引缓冲区
GLuint iBuffer;
glGenBuffers(1, &iBuffer);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, iBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
//3、打开通道，读取数据
//顶点
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, (GLfloat *)NULL + 0);
//顶点颜色
glEnableVertexAttribArray(GLKVertexAttribColor);
glVertexAttribPointer(GLKVertexAttribColor, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, (GLfloat *)NULL + 3);
//纹理
glEnableVertexAttribArray(GLKVertexAttribTexCoord0);
glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, (GLfloat *)NULL + 6);
}
#pragma mark - 3、绘制
-(void)drawPart{
if (!self.myEffect) {
self.myEffect = [[GLKBaseEffect alloc] init];
}
if (self.isHybrid == YES) {
//获取图片路径
NSString *imageFile = [[NSBundle mainBundle] pathForResource:@"mark" ofType:@"jpeg"];
//翻转策略
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:@"1",GLKTextureLoaderOriginBottomLeft, nil];
//获取纹理信息
GLKTextureInfo *textureInfo = [GLKTextureLoader textureWithContentsOfFile:imageFile options:options error:nil];
self.myEffect.texture2d0.enabled = GL_TRUE;
self.myEffect.texture2d0.name = textureInfo.name;
}else{
self.myEffect.texture2d0.enabled = GL_FALSE;
}
//设置投影矩阵
//宽高比
float aspect = self.view.bounds.size.width / self.view.bounds.size.height;
GLKMatrix4 projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(90.0), aspect, 0.1f, 100.0f);
projectionMatrix = GLKMatrix4Scale(projectionMatrix, 1.0f, 1.0f, 1.0f);
self.myEffect.transform.projectionMatrix = projectionMatrix;
//设置视图模型矩阵
//把物体往里移动10，改变单元矩阵
GLKMatrix4 modelViewMatrix = GLKMatrix4Translate(GLKMatrix4Identity, 0.0f, 0.0f, -2.5f);
self.myEffect.transform.modelviewMatrix = modelViewMatrix;
}
#pragma mark - 4、添加底部按钮，控制旋转、切换
-(void)setUpBottomButtons{
NSArray *array = @[@"x",@"y",@"z",@"混合"];
#define AppViewW 50
#define AppViewH 50
#define KColCount 4 //每行的个数
//每个Button的起始位置
#define KStartX 30
#define KStartY self.view.frame.size.height - 80
//两个Button之间的间距
#define SpaceX 30
#define SpaceY 0
for (int i=0; i