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效果演示
效果演示.gif
1.创建项目，进行基本配置
- 使用xcode创建一个App项目
- 导入纹理图片cTest
- 创建CCViewController，继承自GLKViewController
- 修改Main.storyboard的配置，将控制器class设置为CCViewController，将view设置为GLKView，并创建x,y,z按钮，并设置IBAction点击事件
- 导入#import <GLKit/GLKit.h>
2.设置需要使用到的属性
#import "CCViewController.h"
@interface CCViewController()
// 绘图上下文
@property(nonatomic,strong)EAGLContext *mContext;
/// 基础效果类
@property(nonatomic,strong)GLKBaseEffect *mEffect;
/// 绘制的顶点个数
@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 {
// GCD定时器
dispatch_source_t timer;
}
3.新建上下文和设置图层
-(void)setupContext {
//1.新建OpenGL ES上下文
self.mContext = [[EAGLContext alloc]initWithAPI:kEAGLRenderingAPIOpenGLES2];
// 获取OpenGL ES 绘制View
GLKView *view = (GLKView *)self.view;
// 设置上下文到view
view.context = self.mContext;
// 设置颜色缓冲区格式
view.drawableColorFormat = GLKViewDrawableColorFormatRGBA8888;
// 设置深度缓冲区格式
view.drawableDepthFormat = GLKViewDrawableDepthFormat24;
// 设为当前上下文
[EAGLContext setCurrentContext:self.mContext];
// 开启深度测试
glEnable(GL_DEPTH_TEST);
}
4.渲染图形
-(void)render {
//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, 0.0f, 0.0f, 0.5f, 0.0f, 1.0f,//左上
0.5f, 0.5f, 0.0f, 0.0f, 0.5f, 0.0f, 1.0f, 1.0f,//右上
-0.5f, -0.5f, 0.0f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f,//左下
0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 0.5f, 1.0f, 0.0f,//右下
0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.5f, 0.5f,//顶点
};
//2.绘图索引,构成三角形的顶点
GLuint indices[] =
{
0, 3, 2,
0, 1, 3,
0, 2, 4,
0, 4, 1,
2, 3, 4,
1, 4, 3,
};
//顶点个数
self.count = sizeof(indices) /sizeof(GLuint);
//将顶点数组放入数组缓冲区中 GL_ARRAY_BUFFER
GLuint buffer;
glGenBuffers(1, &buffer);
glBindBuffer(GL_ARRAY_BUFFER, buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(attrArr), attrArr, GL_STATIC_DRAW);
//将索引数组存储到索引缓冲区 GL_ELEMENT_ARRAY_BUFFER
GLuint index;
glGenBuffers(1, &index);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, index);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
//使用顶点数据
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, NULL);
//使用颜色数据
glEnableVertexAttribArray(GLKVertexAttribColor);
glVertexAttribPointer(GLKVertexAttribColor, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, (GLfloat *)NULL + 3);
//使用纹理数据
glEnableVertexAttribArray(GLKVertexAttribTexCoord0);
glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, (GLfloat *)NULL + 6);
//获取纹理路径
NSString *filePath = [[NSBundle mainBundle]pathForResource:@"cTest" ofType:@"jpg"];
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:@"1",GLKTextureLoaderOriginBottomLeft, nil];
GLKTextureInfo *textureInfo = [GLKTextureLoader textureWithContentsOfFile:filePath options:options error:nil];
//着色器GLKBaseEffect有3个光源,2个纹理
self.mEffect = [[GLKBaseEffect alloc]init];
self.mEffect.texture2d0.enabled = GL_TRUE;
self.mEffect.texture2d0.name = textureInfo.name;
//投影视图,设置为透视投影
CGSize size = self.view.bounds.size;
float aspect = fabs(size.width / size.height);
GLKMatrix4 projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(90.0), aspect, 0.1f, 10.f);
// 可以对投影矩阵进行缩放
projectionMatrix = GLKMatrix4Scale(projectionMatrix, 1.0f, 1.0f, 1.0f);
// 将投影效果设置到GLKBaseEffect
self.mEffect.transform.projectionMatrix = projectionMatrix;
//模型视图,往-z轴平移2个单位
GLKMatrix4 modelViewMatrix = GLKMatrix4Translate(GLKMatrix4Identity, 0.0f, 0.0f, -2.0f);
self.mEffect.transform.modelviewMatrix = modelViewMatrix;
//定时器
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);
}
5.实现GLKView的代理
- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect {
// 清屏,设置清屏颜色
glClearColor(0.3f, 0.3f, 0.3f, 1.0f);
// 清除颜色缓存区和深度缓存区
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// 准备画
[self.mEffect prepareToDraw];
// 绘制索引的三角形
glDrawElements(GL_TRIANGLES, self.count, GL_UNSIGNED_INT, 0);
}
6.实现常见变化函数update
-(void)update {
// 模型矩阵
GLKMatrix4 modelViewMatrix = GLKMatrix4Translate(GLKMatrix4Identity, 0.0f, 0.0f, -2.0f);
// 模型矩阵旋转
modelViewMatrix = GLKMatrix4RotateX(modelViewMatrix, self.XDegree);
modelViewMatrix = GLKMatrix4RotateY(modelViewMatrix, self.YDegree);
modelViewMatrix = GLKMatrix4RotateZ(modelViewMatrix, self.ZDegree);
// 将旋转效果设置到mEffect
self.mEffect.transform.modelviewMatrix = modelViewMatrix;
}
7.更换x,y,z轴旋转
- (IBAction)XClick:(id)sender {
_XB = !_XB;
}
- (IBAction)YClick:(id)sender {
_YB = !_YB;
}
- (IBAction)ZClick:(id)sender {
_ZB = !_ZB;
}
