1

我创建了一个允许我显示的程序，3D objects现在我想制作一个cut与另一个对象相关的内容。这是我的结果：屏幕。

屏幕显示我们可以通过切割部分看到。所以我决定用 ashader来填充这个切割部分。

我尝试加载 ashader然后在 a 中使用它，glUniform3f但这不起作用。我在互联网上进行了几次搜索，没有结果。

这是我要加载的课程shader：

- (id)initWithVertexShaderFilename:(NSString *)vShaderFilename
        fragmentShaderFilename:(NSString *)fShaderFilename
{
NSLog(fShaderFilename);
if (self = [super init])
{
    attributes = [[NSMutableArray alloc] init];
    NSString *vertShaderPathname, *fragShaderPathname;
    program = glCreateProgram();

    vertShaderPathname =[[NSBundle mainBundle]
                         pathForResource:vShaderFilename
                         ofType:@"vsh"
                         inDirectory:@"Shader"];

    if (![self compileShader:&vertShader
                        type:GL_VERTEX_SHADER
                        file:vertShaderPathname])
        NSLog(@"Failed to compile vertex shader");
    else
        NSLog(@"Vertex Shader OK");

    fragShaderPathname = [[NSBundle mainBundle]
                          pathForResource:fShaderFilename
                          ofType:@"fsh"
                          inDirectory:@"Shader"];

    if (![self compileShader:&fragShader
                        type:GL_FRAGMENT_SHADER
                        file:fragShaderPathname])
        NSLog(@"Failed to compile fragment shader");
    else
        NSLog(@"Fragment shader OK");
    glAttachShader(program, vertShader);
    glAttachShader(program, fragShader);
}

return self;
}

- (BOOL)compileShader:(GLuint *)shader
             type:(GLenum)type
             file:(NSString *)file
{
    NSLog(@"bonjour");
    GLint status;
    const GLchar *source;

    source =
    (GLchar *)[[NSString stringWithContentsOfFile:file
                                     encoding:NSUTF8StringEncoding
                                        error:nil] UTF8String];
   if (!source)
   {
       NSLog(@"Failed to load vertex shader");
       return NO;
   }

   *shader = glCreateShader(type);
   glShaderSource(*shader, 1, &source, NULL);
   glCompileShader(*shader);

   glGetShaderiv(*shader, GL_COMPILE_STATUS, &status);
   NSString *intString = [NSString stringWithFormat:@"%d", status];
   return status = GL_TRUE;
}

#pragma mark -
- (void)addAttribute:(NSString *)attributeName
{
   if (![attributes containsObject:attributeName])
   {
       [attributes addObject:attributeName];
       glBindAttribLocation(program,
                         [attributes indexOfObject:attributeName],
                         [attributeName UTF8String]);
   }
}

- (GLuint)attributeIndex:(NSString *)attributeName
{
   return [attributes indexOfObject:attributeName];
}

- (GLuint)uniformIndex:(NSString *)uniformName
{
   return glGetUniformLocation(program, [uniformName UTF8String]);
}

#pragma mark -
- (BOOL)link
{
   GLint status;

   glLinkProgram(program);
   glValidateProgram(program);

   glGetProgramiv(program, GL_LINK_STATUS, &status);
   if (status == GL_FALSE)
       return NO;

   if (vertShader)
       glDeleteShader(vertShader);
   if (fragShader)
       glDeleteShader(fragShader);

   return YES;
}

- (void)use
{
    glUseProgram(program);
}

shaders这是在主类中初始化 my 的函数：

- (void)setup
{
   GLShader *theProgram = [[GLShader alloc] initWithVertexShaderFilename:@"shader"
                                               fragmentShaderFilename:@"shader"];
   self.program = theProgram;

   [self.program addAttribute:@"position"];
   [self.program addAttribute:@"textureCoordinates"];

   if (![self.program link])
   {
       NSLog(@"Link failed");

       NSString *progLog = [self.program programLog];
       NSLog(@"Program Log: %@", progLog);

       NSString *fragLog = [self.program fragmentShaderLog];
       NSLog(@"Frag Log: %@", fragLog);

       NSString *vertLog = [self.program vertexShaderLog];
       NSLog(@"Vert Log: %@", vertLog);

       //[(GLView *)self.view stopAnimation];
       self.program = nil;
   }

   textureCoordinateAttribute = [program attributeIndex:@"textureCoordinates"];
   colorUniform = [program uniformIndex:@"uColor"];
   textureUniform = [program uniformIndex:@"texture"];
   //colorUniform = glGetUniformLocation(self.program, "uColor");

   glEnable(GL_DEPTH_TEST);
   glEnable(GL_CULL_FACE);
   glEnable(GL_TEXTURE_2D);
   glEnable(GL_BLEND);
   glBlendFunc(GL_ONE, GL_ZERO);    
}

这是我要使用的功能shader：

 -(void) draw
 {
     [self.program use];
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
     glDepthMask(true);
     lUniform3f(colorUniform,1.0, 1.0, 0.5);
     [self drawSubtraction:image1 with:image2];

 }

这是我的fragment shader：

precision highp float;

uniform vec3 uColor;
uniform vec3 uLight;

varying vec3 vNormal;

const float alpha = 0.7;
void main(void) {
float val = dot( vNormal, uLight ) * 0.4 + 0.6;

gl_FragColor = vec4( uColor * val, alpha);
}

难道我做错了什么 ？有人有可以帮助我的想法吗？

谢谢。

4

1 回答 1

0

您的着色器代码看起来不错。确保将“textureCoordinates”属性正确传递给顶点着色器。您将需要在初始化的某个时刻调用glEnableVertexAttribArray()和。glVertexAttribPointer()根据您渲染模型的方式，您可能需要确保您也正确传递了顶点。

另外我假设[self drawSubtraction:image1 with:image2]电话glDrawArrays()或glDrawElements()在某些时候。

如果您想要一个项目进行比较，Xcode 默认的 OpenGL 游戏项目也是加载着色器的好地方。

于 2013-05-22T19:24:06.023 回答