核心显卡效果：在模拟器上有效，但在设备上无效

发布于 2024-12-20 11:17:14 字数 2691 浏览 3 评论 0 原文

我用 Core Graphics 做了一个简单但有效的浮雕效果。效果很好！但仅限于模拟器... 这是结果：

1st image

我所做的如下： - 从选取的图像中，如果有 Alpha，我将其取出并用白色填充它。 - 我将此 RGB 图像转换为灰度图像 - 我反转该图像的颜色

，然后调用自定义方法来使用参数创建效果：

canvasImg：要遮盖的半透明图像
maskImg：我刚刚创建的图像，灰度和反转：

2nd image

opacity：结果图像的不透明度

该方法然后制作一个简单的蒙版，应用阴影和不透明度并返回一个全新的 UIImage。我不明白为什么它在模拟器中起作用，也不在设备中起作用。在设备中运行时，我得到一个非空的 UIImage... 请帮忙！

这是代码：

- (UIImage *)stampImage:(UIImage *)canvasImg withMask:(UIImage *)maskImg withOpacity:(CGFloat)opacity
{
//Creating the mask Image
CGContextRef mainViewContentContext;
CGColorSpaceRef colorSpace;
colorSpace = CGColorSpaceCreateDeviceRGB();
mainViewContentContext = CGBitmapContextCreate(NULL, maskImg.size.width, maskImg.size.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
CGColorSpaceRelease(colorSpace);

if (mainViewContentContext == NULL) return NULL;

CGContextClipToMask(mainViewContentContext, CGRectMake(0, 0, maskImg.size.width, maskImg.size.height), maskImg.CGImage);
CGContextDrawImage(mainViewContentContext, CGRectMake(0, 0, maskImg.size.width, maskImg.size.height), canvasImg.CGImage);
CGContextSetAllowsAntialiasing(mainViewContentContext, true);
CGContextSetShouldAntialias(mainViewContentContext, true);
CGImageRef mainViewContentBitmapContext = CGBitmapContextCreateImage(mainViewContentContext);
CGContextRelease(mainViewContentContext);
UIImage *maskedImage = [UIImage imageWithCGImage:mainViewContentBitmapContext];
CGImageRelease(mainViewContentBitmapContext);

//Giving some Drop shadows
CGColorSpaceRef colourSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef shadowContext = CGBitmapContextCreate(NULL, maskedImage.size.width + 10, maskedImage.size.height + 10,
                                                   CGImageGetBitsPerComponent(maskedImage.CGImage), 0, 
                                                   colourSpace, kCGImageAlphaPremultipliedLast);
CGColorSpaceRelease(colourSpace);
CGContextSetShadowWithColor(shadowContext, CGSizeMake(0, -1), 1, [UIColor colorWithWhite:1.0 alpha:0.3].CGColor);
CGContextSetAllowsAntialiasing(shadowContext, true);
CGContextSetShouldAntialias(shadowContext, true);
CGContextDrawImage(shadowContext, CGRectMake(0, 10, maskedImage.size.width, maskedImage.size.height), maskedImage.CGImage);
CGImageRef shadowedCGImage = CGBitmapContextCreateImage(shadowContext);
CGContextRelease(shadowContext);

UIImage *stampImg = [UIImage imageWithCGImage:shadowedCGImage];
CGImageRelease(shadowedCGImage);

return stampImg;

}

原文

I have done a simple but effective emboss effect with Core Graphics.
It works great! But only in simulator...
Here is the result:

1st image

What I do is the following:
- From a picked image, I take the alpha out if it has and I fill it with white.
- I transform this RGB image to Grayscale
- I invert colors of this image

I then call a custom method to create the effect with parameters:

canvasImg: a semi-transparent image to mask on
maskImg: the image I just created, grayscale and inverted:

2nd image

opacitity: the opacity of the resulting image

The method then makes a simple mask, applies shadows and oppacity and returns a brand new UIImage.
I can't understand why in the simulator it does work, nor the device.
While running in the device, I get a non-null UIImage tho...
Please help!

Here is the code:

- (UIImage *)stampImage:(UIImage *)canvasImg withMask:(UIImage *)maskImg withOpacity:(CGFloat)opacity
{
//Creating the mask Image
CGContextRef mainViewContentContext;
CGColorSpaceRef colorSpace;
colorSpace = CGColorSpaceCreateDeviceRGB();
mainViewContentContext = CGBitmapContextCreate(NULL, maskImg.size.width, maskImg.size.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
CGColorSpaceRelease(colorSpace);

if (mainViewContentContext == NULL) return NULL;

CGContextClipToMask(mainViewContentContext, CGRectMake(0, 0, maskImg.size.width, maskImg.size.height), maskImg.CGImage);
CGContextDrawImage(mainViewContentContext, CGRectMake(0, 0, maskImg.size.width, maskImg.size.height), canvasImg.CGImage);
CGContextSetAllowsAntialiasing(mainViewContentContext, true);
CGContextSetShouldAntialias(mainViewContentContext, true);
CGImageRef mainViewContentBitmapContext = CGBitmapContextCreateImage(mainViewContentContext);
CGContextRelease(mainViewContentContext);
UIImage *maskedImage = [UIImage imageWithCGImage:mainViewContentBitmapContext];
CGImageRelease(mainViewContentBitmapContext);

//Giving some Drop shadows
CGColorSpaceRef colourSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef shadowContext = CGBitmapContextCreate(NULL, maskedImage.size.width + 10, maskedImage.size.height + 10,
                                                   CGImageGetBitsPerComponent(maskedImage.CGImage), 0, 
                                                   colourSpace, kCGImageAlphaPremultipliedLast);
CGColorSpaceRelease(colourSpace);
CGContextSetShadowWithColor(shadowContext, CGSizeMake(0, -1), 1, [UIColor colorWithWhite:1.0 alpha:0.3].CGColor);
CGContextSetAllowsAntialiasing(shadowContext, true);
CGContextSetShouldAntialias(shadowContext, true);
CGContextDrawImage(shadowContext, CGRectMake(0, 10, maskedImage.size.width, maskedImage.size.height), maskedImage.CGImage);
CGImageRef shadowedCGImage = CGBitmapContextCreateImage(shadowContext);
CGContextRelease(shadowContext);

UIImage *stampImg = [UIImage imageWithCGImage:shadowedCGImage];
CGImageRelease(shadowedCGImage);

return stampImg;

}

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抹茶夏天i‖ 2024-12-27 11:17:14

还要注意设备与模拟器的内存限制。我已经有了可以在模拟器上构建和运行良好的 CG 逻辑；相同的逻辑将构建并运行，不会在设备上发出任何错误，但视觉结果不是所需的结果。我建议在一个相当小的图像上尝试你的逻辑，以验证它是否可以在设备上运行。我不得不放弃一些我想出的非常酷的图像屏蔽功能，因为该设备没有足够的能力来处理更大的图像。