有个GLKit框架可以简化基于OpenGL或者OpenGL ES的应用开发。这个框架功能介绍可以参考以下链接：
https://www.jianshu.com/p/e19dd7a9c74c
1、新建一个View继承自GLKView
DXPanoramaPhotoView.h
#import
#import
#import
@interface DXPanoramaPhotoView :GLKView
/// 传过来的VR全景图片
@property (nonatomic,copy)NSString *photoURL;
@end
.m
#import "DXPanoramaPhotoView.h"
#import "Sphere.h"
@interface DXPanoramaPhotoView ()
/// 相机广角角度
@property (nonatomic,assign)CGFloat overture;
/// 索引数
@property (nonatomic,assign)int numIndices;
/// 顶点索引缓存指针
@property (nonatomic,assign)GLuint vertexIndicesBufferID;
/// 顶点缓存指针
@property (nonatomic,assign)GLuint vertexBufferID;
/// 纹理缓存指针
@property (nonatomic,assign)GLuint vertexTexCoordID;
/// 着色器
@property (nonatomic,strong)GLKBaseEffect *effect;
/// 图片纹理信息
@property (nonatomic,strong)GLKTextureInfo *textureInfo;
/// 模型坐标系
@property (nonatomic,assign)GLKMatrix4 modelViewMatrix;
/// 拖拽手势
@property (nonatomic,assign)CGFloat panX;
@property (nonatomic,assign)CGFloat panY;
@property (nonatomic,assign)CGFloat sphereSliceNum;
/// 球体半径
@property (nonatomic,assign)CGFloat sphereRadius;
@property (nonatomic,assign)CGFloat sphereScale;
@property (nonatomic,strong)CMMotionManager *motionManager;
@property (nonatomic,strong)UIPanGestureRecognizer *pan;
@end
@implementation DXPanoramaPhotoView
-(CMMotionManager *)motionManager
{
if (!_motionManager) {
_motionManager = [[CMMotionManager alloc]init];
_motionManager.deviceMotionUpdateInterval = 1.0 / 60.0;//更新间隔
_motionManager.showsDeviceMovementDisplay = YES;
}
return _motionManager;
}
-(UIPanGestureRecognizer *)pan
{
if (!_pan) {
_pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panActionDidClick:)];
}
return _pan;
}
-(instancetype)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame]) {
self.modelViewMatrix = GLKMatrix4Identity;
self.sphereSliceNum = 200;
self.sphereRadius = 1.0;
self.sphereScale = 300;
/// 初始化GLKView
[self setupGLKView];
/// 设置buffers
[self setupBuffer];
/// 检测屏幕位置(加速器与陀螺仪)
[self startDeviceMotion];
/// 添加拖拽手势
[self addPanGestureRecognizer];
[self addDisplayLink];
}
return self;
}
-(void)setPhotoURL:(NSString *)photoURL
{
_photoURL = photoURL;
[self runningTexture:photoURL];
}
-(void)glkView:(GLKView *)view drawInRect:(CGRect)rect
{
// 清除缓冲区的内容
glClearColor(0, 0, 0, 1);
// 清除颜色缓冲区与深度缓冲区内容
glClear((GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT));
// 渲染着色器
[_effect prepareToDraw];
glDrawElements((GL_TRIANGLES), (_numIndices),(GL_UNSIGNED_SHORT), nil);
[self update];
}
- (void)update
{
float aspect = fabs(self.bounds.size.width / self.bounds.size.height);
GLKMatrix4 projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(85.0), aspect, 0.1, 400.0);
projectionMatrix = GLKMatrix4Scale(projectionMatrix, -1.0, 1.0, 1.0);
if (_motionManager.deviceMotion != nil){
float w = _motionManager.deviceMotion.attitude.quaternion.w;
float x = _motionManager.deviceMotion.attitude.quaternion.x;
float y = _motionManager.deviceMotion.attitude.quaternion.y;
float z = _motionManager.deviceMotion.attitude.quaternion.z;
projectionMatrix = GLKMatrix4RotateX(projectionMatrix, -(0.005 * _panY));
GLKQuaternion quaternion = GLKQuaternionMake(-x, y, z, w);
GLKMatrix4 rotation = GLKMatrix4MakeWithQuaternion(quaternion);
projectionMatrix = GLKMatrix4Multiply(projectionMatrix, rotation);
/// 为了保证在水平放置手机的时候, 是从下往上看, 因此首先坐标系沿着x轴旋转90度
projectionMatrix = GLKMatrix4RotateX(projectionMatrix, -(M_PI_2));
_effect.transform.projectionMatrix = projectionMatrix;
GLKMatrix4 modelViewMatrix = GLKMatrix4Identity;
modelViewMatrix = GLKMatrix4RotateY(modelViewMatrix,(0.005 * _panX));
_effect.transform.modelviewMatrix = modelViewMatrix;
}
}
- (void)setupGLKView
{
/// 设置颜色格式和深度格式
self.drawableColorFormat = GLKViewDrawableColorFormatRGBA8888;
self.drawableDepthFormat = GLKViewDrawableDepthFormat24;
self.delegate = self;
self.context = [[EAGLContext alloc]initWithAPI:kEAGLRenderingAPIOpenGLES2];
//将此“EAGLContext”实例设置为OpenGL的“当前激活”的“Context”
[EAGLContext setCurrentContext:self.context];
/// 注意: 激活深度检测,设置深度检测一定要放在设置上一句的下面, 要不然context还没有激活
glEnable(GL_DEPTH_TEST);
}
- (void)setupBuffer
{
float *vertices = 0;// 顶点
float *texCoord = 0;// 纹理
uint16_t *indices = 0;// 索引
int32_t numVertices = 0;
/// 编译C文件 获取顶点/纹理/索引
self.numIndices = initSphere(_sphereSliceNum, _sphereRadius, &vertices, &texCoord, &indices, &numVertices);
/// 加载顶点索引数据
glGenBuffers(1, &_vertexIndicesBufferID); // 申请内存
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _vertexIndicesBufferID);// 将命名的缓冲对象绑定到指定的类型上去
glBufferData(GL_ELEMENT_ARRAY_BUFFER, _numIndices * sizeof(GLushort),indices, GL_STATIC_DRAW);
/// 加载顶点坐标数据
glGenBuffers(1, &_vertexBufferID);
glBindBuffer((GL_ARRAY_BUFFER), _vertexBufferID);
glBufferData((GL_ARRAY_BUFFER), (numVertices) * 3 * sizeof(GLfloat), vertices, (GL_STATIC_DRAW));
/// 激活顶点位置属性
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(GLKVertexAttribPosition, 3, (GL_FLOAT), GL_FALSE, sizeof(GLfloat) * 3, nil);
// 纹理
glGenBuffers(1, &_vertexTexCoordID);
glBindBuffer((GL_ARRAY_BUFFER), _vertexTexCoordID);
glBufferData((GL_ARRAY_BUFFER),(numVertices) * 2 * sizeof(GLfloat), texCoord, (GL_DYNAMIC_DRAW));
glEnableVertexAttribArray(GLKVertexAttribTexCoord0);
glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 2, nil);
free(vertices);
free(texCoord);
free(indices);
}
- (void)startDeviceMotion
{
/**设置初始坐标系, 并开始监控
CMAttitudeReferenceFrameXArbitraryCorrectedZVertical: 描述的参考系默认设备平放(垂直于Z轴)，在X轴上取任意值。实际上当你开始刚开始对设备进行motion更新的时候X轴就被固定了。不过这里还使用了罗盘来对陀螺仪的测量数据做了误差修正
使用pull形式获取数据
*/
[self.motionManager startDeviceMotionUpdates];
_modelViewMatrix = GLKMatrix4Identity;
}
- (void)addPanGestureRecognizer
{
[self addGestureRecognizer:self.pan];
}
- (void)addDisplayLink
{
CADisplayLink *displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(displayAction)];
[displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
}
- (void)runningTexture:(NSString *)photoUrl
{
// 获取图片纹理信息
NSDictionary * options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES],
GLKTextureLoaderOriginBottomLeft,
nil];
//本地图片
// self.textureInfo = [GLKTextureLoader textureWithContentsOfFile:photoUrl options:options error:nil];
//网络图片
self.textureInfo = [GLKTextureLoader textureWithContentsOfURL:[NSURL URLWithString:photoUrl] options:options error:nil];
_effect = [GLKBaseEffect new];
_effect.texture2d0.enabled = GL_TRUE;
_effect.texture2d0.name = _textureInfo.name;
}
#pragma mark - 监听方法
- (void)panActionDidClick:(UIPanGestureRecognizer *)rec
{
CGPoint point = [rec translationInView:rec.view];
_panX += point.x;
_panY += point.y;
// 变换完后设置0
[rec setTranslation:CGPointZero inView:rec.view];
}
- (void)displayAction
{
[self display];
}
@end
****** Sphere类来自https://github.com/cleven1/VRPanorama
2、加载网络VR
//网络
_dxPhotoView = [[DXPanoramaPhotoView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 400)];
_dxPhotoView.photoURL = @"https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1584505024908&di=226b499afd97abe97d10cc1fb92c4a69&imgtype=0&src=http%3A%2F%2Fpic121.huitu.com%2Fres%2F20190525%2F1075369_20190525154106080050_1.jpg";
[self.view addSubview:_dxPhotoView];
如果加载本地的，需要改以下方法：
[GLKTextureLoader textureWithContentsOfFile:photoUrl options:options error:nil];
GitHub上有个小伙伴写的类似的View,也是可以改写成加载网络VR图片。链接如下
https://github.com/bestswifter/BSPanoramaView