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我正在做一個IPhone繪畫應用程序。我想用touchevent繪製圖像的特定部分來查找像素數據,然後使用該像素數據繪製圖像的其餘部分。使用的TouchEvent,我得到了部分的像素值:用顏色填充圖像的一部分
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
startPoint = [[touches anyObject] locationInView:imageView];
NSLog(@"the value of the index is %i",index);
NSString* imageName=[NSString stringWithFormat:@"roof%i", index];
tempColor = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:imageName]];
lastPoint = [touch locationInView:self.view];
lastPoint.y -= 20;
NSString *tx = [[NSString alloc]initWithFormat:@"%.0f", lastPoint.x];
NSString *ty = [[NSString alloc]initWithFormat:@"%.0f", lastPoint.y];
NSLog(@"the vale of the string is %@ and %@",tx,ty);
int ix=[tx intValue];
int iy=[ty intValue];
int z=1;
NSLog(@"the vale of the string is %i and %i and z is %i",ix,iy,z);
[self getRGBAsFromImage:newImage atX:ix andY:iy count1:1];
}
在這裏我得到了圖像的像素數據:
-(void)getRGBAsFromImage:(UIImage*)image atX:(int)xx andY:(int)yy count1:(int)count
{
NSMutableArray *result = [NSMutableArray arrayWithCapacity:count];
// First get the image into your data buffer
CGImageRef imageRef = [image CGImage];
NSUInteger width = CGImageGetWidth(imageRef);
NSUInteger height = CGImageGetHeight(imageRef);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
unsigned char *rawData = malloc(height * width * 4);
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = 8;
CGContextRef context = CGBitmapContextCreate(rawData, width, height,
bitsPerComponent, bytesPerRow, colorSpace,
kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
CGContextRelease(context);
// Now your rawData contains the image data in the RGBA8888 pixel format.
int byteIndex = (bytesPerRow * yy) + xx * bytesPerPixel;
for (int ii = 0 ; ii < count ; ++ii)
{
CGFloat red = (rawData[byteIndex] * 1.0)/255.0;
CGFloat green = (rawData[byteIndex + 1] * 1.0)/255.0;
CGFloat blue = (rawData[byteIndex + 2] * 1.0)/255.0;
CGFloat alpha = (rawData[byteIndex + 3] * 1.0)/255.0;
byteIndex += 4;
NSLog(@"the vale of the rbg of red is %f",red);
UIColor *acolor = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
[result addObject:acolor];
}
free(rawData);
return result;
}
使用耐性值我得到的數據。在這裏我正在努力繪製剩餘部分。
- (BOOL)cgHitTestForArea:(CGRect)area {
BOOL hit = FALSE;
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
float areaFloat = ((area.size.width * 4) * area.size.height);
unsigned char *bitmapData = malloc(areaFloat);
CGContextRef context = CGBitmapContextCreate(bitmapData,
area.size.width,
area.size.height,
8,
4*area.size.width,
colorspace,
kCGImageAlphaPremultipliedLast);
CGContextTranslateCTM(context, -area.origin.x, -area.origin.y);
[self.layer renderInContext:context];
//Seek through all pixels.
float transparentPixels = 0;
for (int i = 0; i < (int)areaFloat ; i += 4) {
//Count each transparent pixel.
if (((bitmapData[i + 3] * 1.0)/255.0) == 0) {
transparentPixels += 1;
}
}
free(bitmapData);
//Calculate the percentage of transparent pixels.
float hitTolerance = [[self.layer valueForKey:@"hitTolerance"]floatValue];
NSLog(@"Apixels: %f hitPercent: %f",transparentPixels,(transparentPixels/areaFloat));
if ((transparentPixels/(areaFloat/4)) < hitTolerance) {
hit = TRUE;
}
CGColorSpaceRelease(colorspace);
CGContextRelease(context);
return hit;
}
任何建議,使這項工作請?
我也看到,我嘗試了很多步驟任何應用程序的例子就在那裏,只是告訴, – Marios
這只是一個洪水填充,需要它的維基百科我看過; – Marios
@arunios你已經解決了這個問題? –