GPUImageAPI文檔之GLProgram類

2019-11-14 17:56:01

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　　GLPRogram是GPUImage中代表openGL ES 中的program，具有glprogram功能。

　　屬性

　　@property(readwrite, nonatomic) BOOL initialized

　　　作用：該屬性用于指示program的初始化工作是否成功，成功返回YES,反之返回NO　

　　　@property(readwrite, copy, nonatomic) NSString *vertexShaderLog

　　　　作用：該屬性用于設置或獲取頂點著色器的日志。

　　　　@property(readwrite, copy, nonatomic) NSString *fragmentShaderLog

　　　　作用：該屬性用于設置或獲取片段著色器的日志。

　　　　@property(readwrite, copy, nonatomic) NSString *programLog

　　　　作用：該屬性用于設置或獲取program的日志。

　　方法

　　　　- (id)initWithVertexShaderString:(NSString *)vShaderString fragmentShaderString:(NSString *)fShaderString

　　　　說明：使用一個頂點著色字符串和一個片段著色字符串創建一個GLProgram對象

　　　　參數：頂點著色字符串，片段著色字符串

　　　　返回：GLProgram對象

　　　　相似方法：- (id)initWithVertexShaderString:(NSString *)vShaderString fragmentShaderFilename:(NSString *)fShaderFilename;
　　　　　　　　　- (id)initWithVertexShaderFilename:(NSString *)vShaderFilename fragmentShaderFilename:(NSString *)fShaderFilename（從文件中讀取內容）

　　　　實現

- (id)initWithVertexShaderString:(NSString *)vShaderString             fragmentShaderString:(NSString *)fShaderString;{    if ((self = [super init]))     {        _initialized = NO;                attributes = [[NSMutableArray alloc] init];        uniforms = [[NSMutableArray alloc] init];        program = glCreateProgram();                if (![self compileShader:&vertShader                             type:GL_VERTEX_SHADER                           string:vShaderString])        {            NSLog(@"Failed to compile vertex shader");        }                // Create and compile fragment shader        if (![self compileShader:&fragShader                             type:GL_FRAGMENT_SHADER                           string:fShaderString])        {            NSLog(@"Failed to compile fragment shader");        }                glAttachShader(program, vertShader);        glAttachShader(program, fragShader);    }        return self;}

　　　　詳解：1.使用glCreateProgram()函數創建一個program

　　　　　　　2.編譯著色器

　　　　　　　3.附加著色器。glAttachShader(program, fragShader)

　　　　- (void)addAttribute:(NSString *)attributeName

　　　　說明：該方法用于向一個program對象中添加屬性

　　　　參數：需要添加的屬性名稱

　　　　返回：void

　　　　實現：

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

　　　　詳解：void glBindAttribLocation( GLuint program, GLuint index,const GLchar *name)函數用來將屬性綁定到具體位置。program是使用的program對象，index是位置索引，*name是需要綁定的屬性名

　　　　- (GLuint)attributeIndex:(NSString *)attributeName

　　　　說明：返回具體屬性名的索引

　　　　參數：指定的屬性名

　　　　返回：指定屬性名的索引

　　　　- (GLuint)uniformIndex:(NSString *)uniformName

　　　　說明:返回Uniform的索引

　　　　參數：指定的Uniform名

　　　　返回：指定Uniform的索引

　　　　- (BOOL)link

　　　　說明：判斷program是否link成功

　　　 返回：YES說明link成功，反之失敗

　　　 實現：

- (BOOL)link{    GLint status;        glLinkProgram(program);        glGetProgramiv(program, GL_LINK_STATUS, &status);    if (status == GL_FALSE)        return NO;        if (vertShader)    {        glDeleteShader(vertShader);        vertShader = 0;    }    if (fragShader)    {        glDeleteShader(fragShader);        fragShader = 0;    }        self.initialized = YES;    return YES;}

　　　 詳解：glLinkProgram(program)函數link一個創建好的program對象，glGetProgramiv(program, GL_LINK_STATUS, &status)用來查詢link結果。

　　　　- (void)use

　　　　說明：使用program

　　　　
　　　　- (void)validate

　　　　說明：program對象是否有效

　　　　- (BOOL)compileShader:(GLuint *)shader type:(GLenum)type string:(NSString *)shaderString

　　　　說明：編譯著色器

　　　　參數：shader是著色器 type為著色器類型（頂點和片段） shaderString為著色器內容字符串。

　　　　實現

- (BOOL)compileShader:(GLuint *)shader                  type:(GLenum)type                string:(NSString *)shaderString{//    CFAbsoluteTime startTime = CFAbsoluteTimeGetCurrent();    GLint status;    const GLchar *source;        source =       (GLchar *)[shaderString 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);    if (status != GL_TRUE)    {        GLint logLength;        glGetShaderiv(*shader, GL_INFO_LOG_LENGTH, &logLength);        if (logLength > 0)        {            GLchar *log = (GLchar *)malloc(logLength);            glGetShaderInfoLog(*shader, logLength, &logLength, log);            if (shader == &vertShader)            {                self.vertexShaderLog = [NSString stringWithFormat:@"%s", log];            }            else            {                self.fragmentShaderLog = [NSString stringWithFormat:@"%s", log];            }            free(log);        }    }        //    CFAbsoluteTime linkTime = (CFAbsoluteTimeGetCurrent() - startTime);//    NSLog(@"Compiled in %f ms", linkTime * 1000.0);    return status == GL_TRUE;}

#import <Foundation/Foundation.h>#if TARGET_ipHONE_SIMULATOR || TARGET_OS_IPHONE#import <OpenGLES/ES2/gl.h>#import <OpenGLES/ES2/glext.h>#else#import <OpenGL/OpenGL.h>#import <OpenGL/gl.h>#endif@interface GLProgram : NSObject {    NSMutableArray  *attributes;    NSMutableArray  *uniforms;    GLuint          program,    vertShader,     fragShader;    }@property(readwrite, nonatomic) BOOL initialized;@property(readwrite, copy, nonatomic) NSString *vertexShaderLog;@property(readwrite, copy, nonatomic) NSString *fragmentShaderLog;@property(readwrite, copy, nonatomic) NSString *programLog;- (id)initWithVertexShaderString:(NSString *)vShaderString             fragmentShaderString:(NSString *)fShaderString;- (id)initWithVertexShaderString:(NSString *)vShaderString           fragmentShaderFilename:(NSString *)fShaderFilename;- (id)initWithVertexShaderFilename:(NSString *)vShaderFilename             fragmentShaderFilename:(NSString *)fShaderFilename;- (void)addAttribute:(NSString *)attributeName;- (GLuint)attributeIndex:(NSString *)attributeName;- (GLuint)uniformIndex:(NSString *)uniformName;- (BOOL)link;- (void)use;- (void)validate;@end

#import "GLProgram.h"// START:typedefs#pragma mark Function Pointer Definitionstypedef void (*GLInfoFunction)(GLuint program, GLenum pname, GLint* params);typedef void (*GLLogFunction) (GLuint program, GLsizei bufsize, GLsizei* length, GLchar* infolog);// END:typedefs#pragma mark -#pragma mark Private Extension Method Declaration// START:extension@interface GLProgram()- (BOOL)compileShader:(GLuint *)shader                  type:(GLenum)type                string:(NSString *)shaderString;@end// END:extension#pragma mark -@implementation GLProgram// START:init@synthesize initialized = _initialized;- (id)initWithVertexShaderString:(NSString *)vShaderString             fragmentShaderString:(NSString *)fShaderString;{    if ((self = [super init]))     {        _initialized = NO;                attributes = [[NSMutableArray alloc] init];        uniforms = [[NSMutableArray alloc] init];        program = glCreateProgram();                if (![self compileShader:&vertShader                             type:GL_VERTEX_SHADER                           string:vShaderString])        {            NSLog(@"Failed to compile vertex shader");        }                // Create and compile fragment shader        if (![self compileShader:&fragShader                             type:GL_FRAGMENT_SHADER                           string:fShaderString])        {            NSLog(@"Failed to compile fragment shader");        }                glAttachShader(program, vertShader);        glAttachShader(program, fragShader);    }        return self;}- (id)initWithVertexShaderString:(NSString *)vShaderString           fragmentShaderFilename:(NSString *)fShaderFilename;{    NSString *fragShaderPathname = [[NSBundle mainBundle] pathForResource:fShaderFilename ofType:@"fsh"];    NSString *fragmentShaderString = [NSString stringWithContentsOfFile:fragShaderPathname encoding:NSUTF8StringEncoding error:nil];        if ((self = [self initWithVertexShaderString:vShaderString fragmentShaderString:fragmentShaderString]))     {    }        return self;}- (id)initWithVertexShaderFilename:(NSString *)vShaderFilename             fragmentShaderFilename:(NSString *)fShaderFilename;{    NSString *vertShaderPathname = [[NSBundle mainBundle] pathForResource:vShaderFilename ofType:@"vsh"];    NSString *vertexShaderString = [NSString stringWithContentsOfFile:vertShaderPathname encoding:NSUTF8StringEncoding error:nil];    NSString *fragShaderPathname = [[NSBundle mainBundle] pathForResource:fShaderFilename ofType:@"fsh"];    NSString *fragmentShaderString = [NSString stringWithContentsOfFile:fragShaderPathname encoding:NSUTF8StringEncoding error:nil];        if ((self = [self initWithVertexShaderString:vertexShaderString fragmentShaderString:fragmentShaderString]))     {    }        return self;}// END:init// START:compile- (BOOL)compileShader:(GLuint *)shader                  type:(GLenum)type                string:(NSString *)shaderString{//    CFAbsoluteTime startTime = CFAbsoluteTimeGetCurrent();    GLint status;    const GLchar *source;        source =       (GLchar *)[shaderString 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);    if (status != GL_TRUE)    {        GLint logLength;        glGetShaderiv(*shader, GL_INFO_LOG_LENGTH, &logLength);        if (logLength > 0)        {            GLchar *log = (GLchar *)malloc(logLength);            glGetShaderInfoLog(*shader, logLength, &logLength, log);            if (shader == &vertShader)            {                self.vertexShaderLog = [NSString stringWithFormat:@"%s", log];            }            else            {                self.fragmentShaderLog = [NSString stringWithFormat:@"%s", log];            }            free(log);        }    }        //    CFAbsoluteTime linkTime = (CFAbsoluteTimeGetCurrent() - startTime);//    NSLog(@"Compiled in %f ms", linkTime * 1000.0);    return status == GL_TRUE;}// END:compile#pragma mark -// START:addattribute- (void)addAttribute:(NSString *)attributeName{    if (![attributes containsObject:attributeName])    {        [attributes addObject:attributeName];        glBindAttribLocation(program,                              (GLuint)[attributes indexOfObject:attributeName],                             [attributeName UTF8String]);    }}// END:addattribute// START:indexmethods- (GLuint)attributeIndex:(NSString *)attributeName{    return (GLuint)[attributes indexOfObject:attributeName];}- (GLuint)uniformIndex:(NSString *)uniformName{    return glGetUniformLocation(program, [uniformName UTF8String]);}// END:indexmethods#pragma mark -// START:link- (BOOL)link{//    CFAbsoluteTime startTime = CFAbsoluteTimeGetCurrent();    GLint status;        glLinkProgram(program);        glGetProgramiv(program, GL_LINK_STATUS, &status);    if (status == GL_FALSE)        return NO;        if (vertShader)    {        glDeleteShader(vertShader);        vertShader = 0;    }    if (fragShader)    {        glDeleteShader(fragShader);        fragShader = 0;    }        self.initialized = YES;//    CFAbsoluteTime linkTime = (CFAbsoluteTimeGetCurrent() - startTime);//    NSLog(@"Linked in %f ms", linkTime * 1000.0);    return YES;}// END:link// START:use- (void)use{    glUseProgram(program);}// END:use#pragma mark -- (void)validate;{    GLint logLength;        glValidateProgram(program);    glGetProgramiv(program, GL_INFO_LOG_LENGTH, &logLength);    if (logLength > 0)    {        GLchar *log = (GLchar *)malloc(logLength);        glGetProgramInfoLog(program, logLength, &logLength, log);        self.programLog = [NSString stringWithFormat:@"%s", log];        free(log);    }    }#pragma mark -// START:dealloc- (void)dealloc{    if (vertShader)        glDeleteShader(vertShader);            if (fragShader)        glDeleteShader(fragShader);        if (program)        glDeleteProgram(program);       }// END:dealloc@end