如何在LibGDX中进行混合 [英] How to do blending in LibGDX
问题描述
我基本上想在LibGDX中使用混合模式，但不知道该怎么做。我在互联网上找到了这个图像。我想在LibGDX上做同样的事情。有人可以教我怎么做。
I basically want to play around with blending modes in LibGDX but don't know how to do it. I found this image on internet. I want to do the same thing on LibGDX. Can someone teach me how.
我一直在使用Scene2D。这是我的非工作代码段。
I've been playing around using Scene2D. Here's my non-working snippet.
private class MyGroup extends Group {
Image red, blue;
public MyGroup() {
Texture texture = new Texture(Gdx.files.internal("images/red.png"));
texture.setFilter(TextureFilter.Linear, TextureFilter.Linear);
red = new Image(texture);
texture = new Texture(Gdx.files.internal("images/blue.png"));
texture.setFilter(TextureFilter.Linear, TextureFilter.Linear);
blue = new Image(texture);
red.setX(-25);
blue.setX(25);
}
@Override
public void draw(Batch batch, float parentAlpha) {
batch.end();
batch.begin();
batch.enableBlending();
red.draw(batch, parentAlpha);
Gdx.gl.glEnable(Gdx.gl20.GL_BLEND);
Gdx.gl.glBlendFuncSeparate(
Gdx.gl20.GL_DST_COLOR,
Gdx.gl20.GL_SRC_COLOR,
Gdx.gl20.GL_ONE,
Gdx.gl20.GL_ONE);
blue.draw(batch, parentAlpha);
}
}
推荐答案
我意识到这不是一个新问题，但我想我会为其他任何人分享一些信息，而不知道在OpenGL中渲染这些问题/答案（知道这些术语有很多帮助，所以你不仅仅是猜混合匹配）请注意此网站是我自己学习大部分内容的方式，因此可以在那里找到更完整的信息。
I realize this is not a new question, but I thought I would share some information for anyone else who makes it to this question/answer without knowing much about rendering in OpenGL (Knowing these terms helps a lot so you aren't just guessing mix-and-matching) Note that this site is how I learned most of this myself, so more complete information can be found there.
目标颜色：颜色在缓冲区，除非被修改或用新值覆盖，否则将（最终）被绘制。
Destination Color: the color in the buffer, which will (eventually) be drawn unless it is modified or overwritten with new values.
源颜色：来自的颜色其他渲染命令，可能与目标颜色交互，也可能不与目标颜色交互（取决于我们的设置）
Source Color: the color coming in from additional rendering commands, which may or may not interact with the destination color (depending on our settings)
默认混合等式：最终颜色=（SourceColor * SourceBlendingFactor）+（DestinationColor * DestinationBlendingFactor）（此默认等式可以更改，但我建议在顶部阅读我的源链接以获取有关该的更多信息）
The default blending equation: Final Color = (SourceColor*SourceBlendingFactor)+(DestinationColor*DestinationBlendingFactor) (This default equation can be changed, but I recommend reading my source link at the top for more information on that)
两个BlendingFactors就是我们可以搞得的。我们可以将它们设置为：
The two BlendingFactors are what we can mess with. We can set them to:
GL_ZERO ：RGB（0,0,0）A（0）
GL_ONE ：RGB（1,1,1）A（1）
GL_SOURCE_COLOR ：RGB（sourceR，sourceG，sourceB）A（sourceA）
GL_ONE_MINUS_SRC_COLOR ：RGB（1-sourceR，1-sourceG，1-sourceB）A（1-sourceA）
GL_DST_COLOR ： RGB（destinationR，destinationG，destinationB）A（destinationA）
GL_ONE_MINUS_DST_COLOR ：RGB（1-destinationR，1-destinationG，1-destinationB）A（1-destinationA）
GL_SRC_ALPHA ：RGB（sourceA，sourceA，sourceA）A（sourceA）
GL_ONE_MINUS_SRC_ALPHA ：RGB（1-sourceA，1- sourceA，1-sourceA）A（1-sourceA）
GL_DST_ALPHA ：RGB（destinationA，destinationA，destinationA）A（destinationA）
GL_ONE_MINUS_DST_ALPHA ：RGB（1-destinationA，1-destinationA，1-destinationA）A（1-destinationA）
GL_SRC_ALPHA_SATURATE ：RGB（min（so） urceA，1-destinationA），min（sourceA，1-destinationA），min（sourceA，1-destinationA））A（1）
以下还使用了一些预定义的常量颜色，默认为黑色
GL_CONSTANT_COLOR ：RGB（constantR，constantG，constantB）A（constantA）
GL_ONE_MINUS_CONSTANT_COLOR ：RGB（1-constantR，1-constantG，1-constantB）A（1-constantA）
GL_CONSTANT_ALPHA ：RGB（constantA，constantA，constantA）A（ constantA）
GL_ONE_MINUS_CONSTANT_ALPHA ：RGB（1-constantA，1-constantA，1-constantA）A（1-constantA）
GL_ZERO: RGB(0,0,0) A(0)
GL_ONE: RGB(1,1,1) A(1)
GL_SOURCE_COLOR: RGB(sourceR, sourceG, sourceB) A(sourceA)
GL_ONE_MINUS_SRC_COLOR: RGB(1-sourceR, 1-sourceG, 1-sourceB) A(1-sourceA)
GL_DST_COLOR: RGB(destinationR, destinationG, destinationB) A(destinationA)
GL_ONE_MINUS_DST_COLOR: RGB(1-destinationR, 1-destinationG, 1-destinationB) A(1-destinationA)
GL_SRC_ALPHA: RGB(sourceA, sourceA, sourceA) A(sourceA)
GL_ONE_MINUS_SRC_ALPHA: RGB(1-sourceA, 1-sourceA, 1-sourceA) A(1-sourceA)
GL_DST_ALPHA: RGB(destinationA, destinationA, destinationA) A(destinationA)
GL_ONE_MINUS_DST_ALPHA: RGB(1-destinationA, 1-destinationA, 1-destinationA) A(1-destinationA)
GL_SRC_ALPHA_SATURATE: RGB(min(sourceA, 1-destinationA), min(sourceA, 1-destinationA), min(sourceA, 1-destinationA)) A(1)
The following also uses some predefined constant color, by default it is black
GL_CONSTANT_COLOR: RGB(constantR, constantG, constantB) A(constantA)
GL_ONE_MINUS_CONSTANT_COLOR: RGB(1-constantR, 1-constantG, 1-constantB) A(1-constantA)
GL_CONSTANT_ALPHA: RGB(constantA, constantA, constantA) A(constantA)
GL_ONE_MINUS_CONSTANT_ALPHA: RGB(1-constantA, 1-constantA, 1-constantA) A(1-constantA)
因此所有这些都只是预定义的浮点值，它们与我们的源或目的地相乘，然后被添加到另一个。
So all of these are just predefined float values that are being multiplied with either our source or destination, and then added to the other.
最容易观察到的图像是GL_ZERO和GL_ONE。我们最终会得到ONE的任何一张图片。
The easiest to observe from the image is GL_ZERO and GL_ONE. We end up with whichever image has the ONE.
了解GL_ZERO GL_DST_COLOR
Understanding GL_ZERO with GL_DST_COLOR
当GL_ZERO在目的地时，我们忽略当前缓冲区中的任何颜色信息（因为将所有内容乘以零）。但是，对于源图像上的GL_DST_COLOR，我们最终将r，g，b与源和目标的值相乘。
When GL_ZERO is on the destination, we are ignoring any color information currently in the buffer (because multiplying everything by zero). However, With GL_DST_COLOR also on the source image, we end up multiplying the r, g, b, a values of the source and destination.
这在图像中看起来不错因为示例图像的性质。一个用作纯色图像，而另一个灰度图像看起来和行为几乎像一束光从我们的GL_ZERO设置中显示颜色。
This looks good in the image because of the nature of the example images. One acts as a solid color image, while the other grayscale image looks and acts almost like a beam of light to "reveal" the color out from our GL_ZERO setting.
希望，这有助于解释我们上面可以看到的图像，并帮助每个人了解这些图像实际上是如何混合在一起的。
Hopefully, this helps explain the images we can see above and helps everyone understand how those images are actually being blended together.
这篇关于如何在LibGDX中进行混合的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
