alpha

是通过css解决这个问题,核心css代码如下: .modal-backdrop { filter: alpha(opacity=0)!important; opacity: 0!important; } alpha和opacity通常是决定透明度。 alpha和opacity区别是什么? 相同点: 都是值为0表示完全透明，值为1表示完全不透明。 不同点: alpha可以应用元素特定的属性，只能作用于当前元素，其子元素不能继承，而opacity不仅仅作用于当前元素，也会影响子元素及其子子元素，具有继承性。 来源： https://www.cnblogs.com/youcong/p/11440604.html

Here's my code: void display(void); int main(int argc, char** argv) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGBA); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable( GL_BLEND ); glutInitWindowSize(600,600); glutInitWindowPosition(200,50); glutCreateWindow("glut test"); glutDisplayFunc(display); glutMainLoop(); return 0; } void display() { glClear(GL_COLOR_BUFFER_BIT); glPointSize(8); glBegin(GL_POINTS); glColor4f(.23,.78,.32,1.0); glVertex2f(0,0); glColor4f(.23,.78,.32,0.1); glVertex2f(0.1,0); glEnd(); glFlush(); } The problem is that these two points appear

I want to implement alpha gradient on an image. From 0.5 alfa on top of the image to 0.0 on bottom. Any advice, tutorial, link is welcome. You can use CGImageCreateWithMask to apply a masking image to it. You could generate an appropriate mask simply enough by drawing to a greyscale or alpha-only CGBitmapContext with CGContextDrawLinearGradient . If it's being displayed as the content of a CALayer, you could apply an appropriate masking layer to the parent layer's mask property. You could use a CAGradientLayer with appropriate colors to create this mask. You can draw the image to a

I have an app icon for iOS but Apple doesn't allow alpha to be in the image. How to remove this alpha channel? I only have the png image with me I don't have the source file as my friend did the image for me. Assuming you don't have another image editor, then you can open it in Preview on your Mac, and use the Export option to resave it in a different format- to ensure you get rid of the alpha channel, it might be best to export to JPG (best quality), then open that and export it as a PNG again. Having said that, I suspect you're probably OK submitting an icon with a transparency channel as

I have a PNG image that has an unsupported bitmap graphics context pixel format. Whenever I attempt to resize the image, CGBitmapContextCreate() chokes on the unsupported format I receive the following error (error formatted for easy reading): CGBitmapContextCreate: unsupported parameter combination: 8 integer bits/component; 32 bits/pixel; 3-component colorspace; kCGImageAlphaLast; 1344 bytes/row. The list of supported pixel formats definitely does not support this combination. It appears I need to redraw the image and move the alpha channel information to kCGImageAlphaPremultipliedFirst or

文章目录 部分和有界 证明 结论 一个例题 解 补充：积化和差 补充：和差化积 部分和有界 证明： ∑ sin ⁡ n x \sum\sin nx ∑ sin n x 和 ∑ cos ⁡ n x \sum\cos nx ∑ cos n x 的部分和有界 ( x ∈ ( 0 , 2 π ) ) (x\in(0,2\pi)) ( x ∈ ( 0 , 2 π ) ) 证明 这个证明的技巧性太强了 直接骚操作 2 sin ⁡ x 2 ( 1 2 + ∑ k = 1 n cos ⁡ k x ) 2\sin\frac x2(\frac12+\sum\limits_{k=1}^n\cos kx) 2 sin 2 x ​ ( 2 1 ​ + k = 1 ∑ n ​ cos k x ) = sin ⁡ x 2 + ( sin ⁡ 3 2 x − sin ⁡ x 2 ) + . . . =\sin\frac x2+(\sin\frac32x-\sin\frac x2)+... = sin 2 x ​ + ( sin 2 3 ​ x − sin 2 x ​ ) + . . . . . . + [ sin ⁡ ( n + 1 2 ) x − sin ⁡ ( n − 1 2 ) x ] ...+[\sin(n+\frac12)x-\sin(n-\frac12)x] . . . + [ sin ( n + 2

I am making a game and want to have a single image 'fade' from left to right with the left part of the image having an alpha of 1.0 and the right having an alpha of 0.0. (note: I do not want it to be changing what it looks like over time, like fading in or out, but just fading from left to right and staying constant). An attempt to draw what I want the end result to look like is below: lll lll ll ll l l l l l lll lll ll ll l l l l l lll lll ll ll l l l l l lll lll ll ll l l l l l lll lll ll ll l l l l l lll lll ll ll l l l l l Where the densities of the 'l's represent the alpha I am currently