效果图
本效果在上一章文章代码(
11-3.GLKit-索引绘图案例)的基础加以改造
主要需要修改ViewController里的render渲染图形函数中新增纹理数据及操作
- 顶点数据中增加纹理坐标
//1.顶点数据
// 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
// };
//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
};
- 修改连续顶点之间的偏移量
从6个偏移量变成8个,因为顶点数组增加了数据
//使用顶点数据
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, NULL);//从6个偏移量变成8个,因为顶点数组增加了数据
//使用颜色数据
glEnableVertexAttribArray(GLKVertexAttribColor);
glVertexAttribPointer(GLKVertexAttribColor, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, (GLfloat *)NULL + 3);//从6个偏移量变成8个,因为顶点数组增加了数据
- 使用纹理数据，即将纹理坐标传入顶点着色器
//使用纹理数据
glEnableVertexAttribArray(GLKVertexAttribTexCoord0);
glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, (GLfloat *)NULL + 6);
- 获取纹理图片 & 加载纹理 & 导入图片(本文使用
jielun.jpg)
// ------获取纹理路路径
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"jielun" ofType:@"jpg"];
NSDictionary *option = [NSDictionary dictionaryWithObjectsAndKeys:@"1", GLKTextureLoaderOriginBottomLeft, nil];
GLKTextureInfo *info = [GLKTextureLoader textureWithContentsOfFile:filePath options:option error:nil];
- 在
effect中设置纹理相关信息
//------着色器
self.mEffect = [[GLKBaseEffect alloc] init];
self.mEffect.texture2d0.enabled = GL_TRUE;
self.mEffect.texture2d0.name = info.name;
完整render函数代码
-(void)render
{
//1.顶点数据
// 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
// };
//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
};
//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,
};
//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);//从6个偏移量变成8个,因为顶点数组增加了数据
//使用颜色数据
glEnableVertexAttribArray(GLKVertexAttribColor);
glVertexAttribPointer(GLKVertexAttribColor, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 8, (GLfloat *)NULL + 3);//从6个偏移量变成8个,因为顶点数组增加了数据
//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:@"jielun" ofType:@"png"];
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:@"1",GLKTextureLoaderOriginBottomLeft, nil];
GLKTextureInfo *textureInfo = [GLKTextureLoader textureWithContentsOfFile:filePath options:options error:nil];
//着色器
self.mEffect = [[GLKBaseEffect alloc]init];
self.mEffect.texture2d0.enabled = GL_TRUE;
self.mEffect.texture2d0.name = textureInfo.name;
//投影视图
CGSize size = self.view.bounds.size;
//float aspect = fabs(size.width / size.height);
float aspect = size.width / size.height;
GLKMatrix4 projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(90.0), aspect, 0.1f, 100.0);
projectionMatrix = GLKMatrix4Scale(projectionMatrix, 1.0f, 1.0f, 1.0f);
self.mEffect.transform.projectionMatrix = projectionMatrix;
//模型视图
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);
}