我想制作一个像GPUImage的GPUImageTwoInputFilter这样的新过滤器。
这是我的代码。一个名为IFFourInputFilter的基类，很可能是GPUImageTwoInputFilter。
#import "IFFourInputFilter.h"
NSString *const kIFFourInputTextureVertexShaderString = SHADER_STRING
(
attribute vec4 position;
attribute vec4 inputTextureCoordinate;
attribute vec4 inputTextureCoordinate2;
attribute vec4 inputTextureCoordinate3;
attribute vec4 inputTextureCoordinate4;
varying vec2 textureCoordinate;
varying vec2 textureCoordinate2;
varying vec2 textureCoordinate3;
varying vec2 textureCoordinate4;
void main()
{
gl_Position = position;
textureCoordinate = inputTextureCoordinate.xy;
textureCoordinate2 = inputTextureCoordinate2.xy;
textureCoordinate3 = inputTextureCoordinate3.xy;
textureCoordinate4 = inputTextureCoordinate4.xy;
}
);
@implementation IFFourInputFilter
#pragma mark -
#pragma mark Initialization and teardown
- (id)initWithFragmentShaderFromString:(NSString *)fragmentShaderString;
{
if (!(self = [self initWithVertexShaderFromString:kIFFourInputTextureVertexShaderString fragmentShaderFromString:fragmentShaderString]))
{
return nil;
}
return self;
}
- (id)initWithVertexShaderFromString:(NSString *)vertexShaderString fragmentShaderFromString:(NSString *)fragmentShaderString;
{
if (!(self = [super initWithVertexShaderFromString:vertexShaderString fragmentShaderFromString:fragmentShaderString]))
{
return nil;
}
inputRotation2 = kGPUImageNoRotation;
inputRotation3 = kGPUImageNoRotation;
inputRotation4 = kGPUImageNoRotation;
hasSetTexture1 = NO;
hasSetTexture2 = NO;
hasSetTexture3 = NO;
hasReceivedFrame1 = NO;
hasReceivedFrame2 = NO;
hasReceivedFrame3 = NO;
hasReceivedFrame4 = NO;
frameWasVideo1 = NO;
frameWasVideo2 = NO;
frameWasVideo3 = NO;
frameWasVideo4 = NO;
frameCheckDisabled1 = NO;
frameCheckDisabled2 = NO;
frameCheckDisabled3 = NO;
frameCheckDisabled4 = NO;
frameTime1 = kCMTimeInvalid;
frameTime2 = kCMTimeInvalid;
frameTime3 = kCMTimeInvalid;
frameTime4 = kCMTimeInvalid;
runSynchronouslyOnVideoProcessingQueue(^{
[GPUImageOpenGLESContext useImageProcessingContext];
filterTextureCoordinateAttribute2 = [filterProgram attributeIndex:@"inputTextureCoordinate2"];
filterInputTextureUniform2 = [filterProgram uniformIndex:@"inputImageTexture2"]; // This does assume a name of "inputImageTexture2" for second input texture in the fragment shader
glEnableVertexAttribArray(filterTextureCoordinateAttribute2);
filterTextureCoordinateAttribute3 = [filterProgram attributeIndex:@"inputTextureCoordinate3"];
filterInputTextureUniform3 = [filterProgram uniformIndex:@"inputImageTexture3"]; // This does assume a name of "inputImageTexture2" for second input texture in the fragment shader
glEnableVertexAttribArray(filterTextureCoordinateAttribute3);
filterTextureCoordinateAttribute4 = [filterProgram attributeIndex:@"inputTextureCoordinate4"];
filterInputTextureUniform4 = [filterProgram uniformIndex:@"inputImageTexture4"]; // This does assume a name of "inputImageTexture2" for second input texture in the fragment shader
glEnableVertexAttribArray(filterTextureCoordinateAttribute4);
});
return self;
}
- (void)initializeAttributes;
{
[super initializeAttributes];
[filterProgram addAttribute:@"inputTextureCoordinate2"];
[filterProgram addAttribute:@"inputTextureCoordinate3"];
[filterProgram addAttribute:@"inputTextureCoordinate4"];
}
- (void)disableFrameCheck1;
{
frameCheckDisabled1 = YES;
}
- (void)disableFrameCheck2;
{
frameCheckDisabled2 = YES;
}
- (void)disableFrameCheck3;
{
frameCheckDisabled3 = YES;
}
- (void)disableFrameCheck4;
{
frameCheckDisabled4 = YES;
}
#pragma mark -
#pragma mark Rendering
- (void)renderToTextureWithVertices:(const GLfloat *)vertices textureCoordinates:(const GLfloat *)textureCoordinates sourceTexture:(GLuint)sourceTexture;
{
if (self.preventRendering)
{
return;
}
[GPUImageOpenGLESContext setActiveShaderProgram:filterProgram];
[self setUniformsForProgramAtIndex:0];
[self setFilterFBO];
glClearColor(backgroundColorRed, backgroundColorGreen, backgroundColorBlue, backgroundColorAlpha);
glClear(GL_COLOR_BUFFER_BIT);
glActiveTexture(GL_TEXTURE2);
glBindTexture(GL_TEXTURE_2D, sourceTexture);
glUniform1i(filterInputTextureUniform, 2);
glActiveTexture(GL_TEXTURE3);
glBindTexture(GL_TEXTURE_2D, filterSourceTexture2);
glUniform1i(filterInputTextureUniform2, 3);
glActiveTexture(GL_TEXTURE4);
glBindTexture(GL_TEXTURE_2D, filterSourceTexture3);
glUniform1i(filterInputTextureUniform3, 4);
glActiveTexture(GL_TEXTURE5);
glBindTexture(GL_TEXTURE_2D, filterSourceTexture4);
glUniform1i(filterInputTextureUniform4, 5);
glVertexAttribPointer(filterPositionAttribute, 2, GL_FLOAT, 0, 0, vertices);
glVertexAttribPointer(filterTextureCoordinateAttribute, 2, GL_FLOAT, 0, 0, textureCoordinates);
glVertexAttribPointer(filterTextureCoordinateAttribute2, 2, GL_FLOAT, 0, 0, [[self class] textureCoordinatesForRotation:inputRotation2]);
glVertexAttribPointer(filterTextureCoordinateAttribute3, 2, GL_FLOAT, 0, 0, [[self class] textureCoordinatesForRotation:inputRotation3]);
glVertexAttribPointer(filterTextureCoordinateAttribute4, 2, GL_FLOAT, 0, 0, [[self class] textureCoordinatesForRotation:inputRotation4]);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
- (void)releaseInputTexturesIfNeeded;
{
if (shouldConserveMemoryForNextFrame)
{
[firstTextureDelegate textureNoLongerNeededForTarget:self];
[textureDelegate2 textureNoLongerNeededForTarget:self];
[textureDelegate3 textureNoLongerNeededForTarget:self];
[textureDelegate4 textureNoLongerNeededForTarget:self];
shouldConserveMemoryForNextFrame = NO;
}
}
#pragma mark -
#pragma mark GPUImageInput
- (NSInteger)nextAvailableTextureIndex;
{
if (!hasSetTexture1){
return 0;
}else if (!hasSetTexture2) {
return 1;
}else if (!hasSetTexture3) {
return 2;
}else{
return 3;
}
}
- (void)setInputTexture:(GLuint)newInputTexture atIndex:(NSInteger)textureIndex;
{
switch (textureIndex) {
case 0:
filterSourceTexture = newInputTexture;
hasSetTexture1 = YES;
break;
case 1:
filterSourceTexture2 = newInputTexture;
hasSetTexture2 = YES;
break;
case 2:
filterSourceTexture3 = newInputTexture;
hasSetTexture3 = YES;
break;
case 3:
filterSourceTexture4 = newInputTexture;
break;
default:
break;
}
}
- (void)setInputSize:(CGSize)newSize atIndex:(NSInteger)textureIndex;
{
if (textureIndex == 0)
{
[super setInputSize:newSize atIndex:textureIndex];
if (CGSizeEqualToSize(newSize, CGSizeZero))
{
hasSetTexture1 = NO;
}
}
}
- (void)setInputRotation:(GPUImageRotationMode)newInputRotation atIndex:(NSInteger)textureIndex;
{
switch (textureIndex) {
case 0:
inputRotation = newInputRotation;
break;
case 1:
inputRotation2 = newInputRotation;
break;
case 2:
inputRotation3 = newInputRotation;
break;
case 3:
inputRotation4 = newInputRotation;
break;
default:
break;
}
}
- (CGSize)rotatedSize:(CGSize)sizeToRotate forIndex:(NSInteger)textureIndex;
{
CGSize rotatedSize = sizeToRotate;
GPUImageRotationMode rotationToCheck;
switch (textureIndex) {
case 0:
rotationToCheck = inputRotation;
break;
case 1:
rotationToCheck = inputRotation2;
break;
case 2:
rotationToCheck = inputRotation3;
break;
case 3:
rotationToCheck = inputRotation4;
break;
default:
break;
}
if (GPUImageRotationSwapsWidthAndHeight(rotationToCheck))
{
rotatedSize.width = sizeToRotate.height;
rotatedSize.height = sizeToRotate.width;
}
return rotatedSize;
}
- (void)newFrameReadyAtTime:(CMTime)frameTime atIndex:(NSInteger)textureIndex;
{
outputTextureRetainCount = [targets count];
// You can set up infinite update loops, so this helps to short circuit them
if (hasReceivedFrame1 && hasReceivedFrame2 && hasReceivedFrame3 && hasReceivedFrame4)
{
return;
}
BOOL updatedMovieFrameOppositeStillImage = NO;
switch (textureIndex) {
case 0:
hasReceivedFrame1 = YES;
frameTime1 = frameTime;
if (frameCheckDisabled2)
{
hasReceivedFrame2 = YES;
}
if (frameCheckDisabled3)
{
hasReceivedFrame3 = YES;
}
if (frameCheckDisabled4)
{
hasReceivedFrame4 = YES;
}
if (!CMTIME_IS_INDEFINITE(frameTime))
{
if (CMTIME_IS_INDEFINITE(frameTime2) && CMTIME_IS_INDEFINITE(frameTime3) && CMTIME_IS_INDEFINITE(frameTime4))
{
updatedMovieFrameOppositeStillImage = YES;
}
}
break;
case 1:
hasReceivedFrame2 = YES;
frameTime2 = frameTime;
if (frameCheckDisabled1)
{
hasReceivedFrame1 = YES;
}
if (frameCheckDisabled3)
{
hasReceivedFrame3 = YES;
}
if (frameCheckDisabled4)
{
hasReceivedFrame4 = YES;
}
if (!CMTIME_IS_INDEFINITE(frameTime))
{
if (CMTIME_IS_INDEFINITE(frameTime1) && CMTIME_IS_INDEFINITE(frameTime3) && CMTIME_IS_INDEFINITE(frameTime4))
{
updatedMovieFrameOppositeStillImage = YES;
}
}
break;
case 2:
hasReceivedFrame3 = YES;
frameTime3 = frameTime;
if (frameCheckDisabled1)
{
hasReceivedFrame1 = YES;
}
if (frameCheckDisabled2)
{
hasReceivedFrame2 = YES;
}
if (frameCheckDisabled4)
{
hasReceivedFrame4 = YES;
}
if (!CMTIME_IS_INDEFINITE(frameTime))
{
if (CMTIME_IS_INDEFINITE(frameTime1) && CMTIME_IS_INDEFINITE(frameTime2) && CMTIME_IS_INDEFINITE(frameTime4))
{
updatedMovieFrameOppositeStillImage = YES;
}
}
break;
case 3:
hasReceivedFrame4 = YES;
frameTime4 = frameTime;
if (frameCheckDisabled1)
{
hasReceivedFrame1 = YES;
}
if (frameCheckDisabled3)
{
hasReceivedFrame3 = YES;
}
if (frameCheckDisabled2)
{
hasReceivedFrame2 = YES;
}
if (!CMTIME_IS_INDEFINITE(frameTime))
{
if (CMTIME_IS_INDEFINITE(frameTime1) && CMTIME_IS_INDEFINITE(frameTime3) && CMTIME_IS_INDEFINITE(frameTime2))
{
updatedMovieFrameOppositeStillImage = YES;
}
}
break;
default:
break;
}
// || (hasReceivedFirstFrame && secondFrameCheckDisabled) || (hasReceivedSecondFrame && firstFrameCheckDisabled)
if ((hasReceivedFrame1 && hasReceivedFrame2 && hasReceivedFrame3 && hasReceivedFrame4) || updatedMovieFrameOppositeStillImage)
{
[super newFrameReadyAtTime:frameTime atIndex:0];
hasReceivedFrame1 = NO;
hasReceivedFrame2 = NO;
hasReceivedFrame3 = NO;
hasReceivedFrame4 = NO;
}
}
- (void)setTextureDelegate:(id<GPUImageTextureDelegate>)newTextureDelegate atIndex:(NSInteger)textureIndex;
{
switch (textureIndex) {
case 0:
firstTextureDelegate = newTextureDelegate;
break;
case 1:
textureDelegate2 = newTextureDelegate;
break;
case 2:
textureDelegate3 = newTextureDelegate;
break;
case 3:
textureDelegate4 = newTextureDelegate;
break;
default:
break;
}
}
@end
名为IFAmaroFilter的类扩展了IFFourInputFilter。
#import "IFAmaroFilter.h"
NSString *const kIFAmaroFilterFragmentShaderString = SHADER_STRING
(
precision lowp float;
varying highp vec2 textureCoordinate;
uniform sampler2D inputImageTexture;
uniform sampler2D inputImageTexture2; //blowout;
uniform sampler2D inputImageTexture3; //overlay;
uniform sampler2D inputImageTexture4; //map
void main()
{
vec4 texel = texture2D(inputImageTexture, textureCoordinate);
vec3 bbTexel = texture2D(inputImageTexture2, textureCoordinate).rgb;
texel.r = texture2D(inputImageTexture3, vec2(bbTexel.r, texel.r)).r;
texel.g = texture2D(inputImageTexture3, vec2(bbTexel.g, texel.g)).g;
texel.b = texture2D(inputImageTexture3, vec2(bbTexel.b, texel.b)).b;
vec4 mapped;
mapped.r = texture2D(inputImageTexture4, vec2(texel.r, 0.16666)).r;
mapped.g = texture2D(inputImageTexture4, vec2(texel.g, .5)).g;
mapped.b = texture2D(inputImageTexture4, vec2(texel.b, .83333)).b;
mapped.a = 1.0;
gl_FragColor = texel;
}
);
@implementation IFAmaroFilter
- (id)init;
{
if (!(self = [super initWithFragmentShaderFromString:kIFAmaroFilterFragmentShaderString]))
{
return nil;
}
return self;
}
@end
当我使用滤镜时，我得到了黑色输出。代码如下：
filter = [[IFAmaroFilter alloc] init];
GPUImagePicture *gp1 = [[GPUImagePicture alloc] initWithImage:[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"blackboard1024" ofType:@"png"]]];
GPUImagePicture *gp2 = [[GPUImagePicture alloc] initWithImage:[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"overlayMap" ofType:@"png"]]];
GPUImagePicture *gp3 = [[GPUImagePicture alloc] initWithImage:[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"amaroMap" ofType:@"png"]]];
[stillCamera addTarget:filter atTextureLocation:0];
[gp1 addTarget:filter atTextureLocation:1];
[gp1 processImage];
[gp2 addTarget:filter atTextureLocation:2];
[gp2 processImage];
[gp3 addTarget:filter atTextureLocation:3];
[gp3 processImage];
[filter addTarget:(GPUImageView *)self.view];
答案 0 :(得分：3)
我发现GPUImagePicture会自动释放，因此过滤器不会接收纹理。 如果您遇到同样的问题，请仔细检查纹理的生命控制，观察它们何时被释放。
答案 1 :(得分：1)
我同意周琦的回答，但我想澄清一点。
您需要在接口声明中使用GPUImagePicture属性，以便您的GPUImagePictureObject不会立即自动释放。
在您的界面声明中：
@property (strong, nonatomic) GPUImagePicture *sourcePicture;
在您的实施中：
UIImage *inputImage = [UIImage imageNamed:@"MyPicture.png"];
_sourcePicture = [[GPUImagePicture alloc] initWithImage:inputImage
smoothlyScaleOutput:YES];
[_sourcePicture processImage];
[_videoCamera addTarget:_myFilter];
[_sourcePicture addTarget:_myFilter];
[_myFilter addTarget:_myView];
在此处查看Filter Showcase示例项目中的任何混合过滤器： https://github.com/BradLarson/GPUImage/tree/master/examples/iOS/FilterShowcase
答案 2 :(得分：0)
我曾尝试使用此着色器合并我的三个视频以制作MV效果
filter0 = [[GPUImageThreeInputFilter alloc] initWithFragmentShaderFromString:@"\nprecision highp float;\nuniform sampler2D inputImageTexture; //video\nuniform sampler2D inputImageTexture2; //mv\nuniform sampler2D inputImageTexture3; //alpha\nvarying vec2 textureCoordinate;\nvoid main()\n{\nvec4 video = texture2D(inputImageTexture, textureCoordinate);\nvec4 mv = texture2D(inputImageTexture2, textureCoordinate);\nvec4 alpha = texture2D(inputImageTexture3, textureCoordinate);\ngl_FragColor = video * (1.0 - alpha.r) + mv;\n}"];
我有同样的问题，你能告诉我一些想法吗？