Cocos2d 3.X Shader dimming and darkening

Transfer from http://www.waitingfy.com/archives/1741

1. To save a picture of the shader used

We notice that in this game, we often use some buttons, the art will give two pictures, a slightly darker point, indicating the state of the press. However, such a figure more up, it is more resource-intensive. The sprite changes color to show no such effect. Think of it shader can.

2. Gray is more common

There is a grayed out example in Cocos2d-x, here is a list of shader codes:

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#ifdef GL_ESprecision mediump float;#endif varying vec4 v_fragmentColor;varying vec2 v_texCoord;  voidmain(void){    vec4 c = texture2D(CC_Texture0, v_texCoord);    gl_FragColor.xyz = vec3(0.2126*c.r + 0.7152*c.g + 0.0722*c.b);    gl_FragColor.w = c.w;}

The number of coefficients will be equal to 1, and the different adjustments will have different effects. ：

The first one is the gray, but the effect from the 3rd is still a distance.

3. The principle of darkening

The graphics should be easier to know, I also search to know, we know that white is 1 or 255, black is 0. When a color gets closer to 0, the closer the Black is. That is, as long as the color of each pixel is multiplied by a number smaller than 1, there will be a darkening effect!

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#ifdef GL_ESprecision mediump float;#endif varying vec4 v_fragmentColor;varying vec2 v_texCoord; voidmain(void){    vec4 c = texture2D(CC_Texture0, v_texCoord);    floatgreyNum = 0.75;    vec4 final = c;    final.r = c.r * greyNum;    final.g = c.g * greyNum;    final.b = c.b * greyNum;     gl_FragColor = final;}

I set the 0.75 here.

Eventually:

It's very close to the 3rd target map we need. So you can save half the picture. I wonder if the rendering speed will be slow.

Source URL: http://www.waitingfy.com/archives/1741

Cocos2d 3.X Shader dimming and darkening