OpenGL加载shader代码

电玩女神 2022-08-07 17:39 183阅读 0赞

c++加载shader的代码：

<pre name="code" class="cpp">#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include "glew.h"
    #include "stdafx.h"
    static char *shaderLoadSource(const char *filePath)
    {
    	const size_t blockSize=512;
    	FILE *fp;
    	char buf[blockSize];
    	char *source=NULL;
    	size_t tmp,sourceLength=0;
    
    	fp=fopen(filePath,"r");
    	if(!fp){
    		fprintf(stderr,"shaderLoadSource():Unable to open %s for reading\n",filePath);
    		return NULL;
    	}
    
    	while((tmp=fread(buf,1,blockSize,fp))>0)
    	{
    		char *newSource=(char *)malloc(sourceLength+tmp+1);
    		if(!newSource){
    			fprintf(stderr,"shaderLoadSource():malloc failed\n");
    			if(source){
    				free(source);
    			}
    			return NULL;
    		}
    		if(source){
    			memcpy(newSource,source,sourceLength);
    			free(source);
    		}
    		memcpy(newSource+sourceLength,buf,tmp);
    		source=newSource;
    		sourceLength+=tmp;
    	}
    	fclose(fp);
    	if(source){
    		source[sourceLength]='\0';
    	}
    
    	return source;
    }
    
    static GLuint shaderCompileFromFile(GLenum type,const char *filePath)
    {
    	char *source;
    	GLuint shader;
    	GLint length,result;
    
    	source=shaderLoadSource(filePath);
    	if(!source){
    		return 0;
    	}
    	shader=glCreateShader(type);
    	length=strlen(source);
    	glShaderSource(shader,1,(const char**)&source,&length);
    	glCompileShader(shader);
    	free(source);
    
    	glGetShaderiv(shader,GL_COMPILE_STATUS,&result);
    	if(result==GL_FALSE){
    		char *log;
    		
    		glGetShaderiv(shader,GL_INFO_LOG_LENGTH,&length);
    		log=(char *)malloc(length);
    		glGetShaderInfoLog(shader,length,&result,log);
    		fprintf(stderr,"shaderCompileFromFile(): Unable to compile %s: %s\n",filePath,log);
    		free(log);
    
    		glDeleteShader(shader);
    		return 0;
    	}
    
    	return shader;
    }
    
    void shaderAttachFromFile(GLuint program,GLenum type,const char *filePath)
    {
    	GLuint shader=shaderCompileFromFile(type,filePath);
    	if(shader!=0){
    		glAttachShader(program,shader);
    		glDeleteShader(shader);
    	}
    }

program 需要在场景中初始，参考我的博客相关介绍。