在OpenGL ES 2.0 GLSL中转置mat4 [英] Transpose a mat4 in OpenGL ES 2.0 GLSL

问题描述

我想在OpenGL ES 2.0顶点着色器中转置矩阵，但是显然我的iPad 3不支持GLSL #version 120，这是内置函数transpose(mat4)所必需的.

I'd like to transpose a matrix in my OpenGL ES 2.0 vertex shader, but apparently my iPad 3 doesn't support GLSL #version 120, which is needed for the built-in function transpose(mat4).

我知道有一些方法可以解决此问题，例如在将矩阵传递到图形芯片之前将其在CPU上转置，但是如果我可以将其转置到那里，它将使我的着色器更加简单.

I know there are options to work around that, like transposing the matrix on the CPU before passing it to the graphics chip, but it would make my shader a lot simpler if I could transpose it there.

因此，在iOS 6设备上的着色器中是否可以选择transpose mat4?

So, is there an option to transpose a mat4 in a shader on an iOS 6 device?

另一件事:问题

iPhone中使用了哪个版本的GLSL )?

表示OpenGL ES 2.0使用GLSL 1.20.那么#version 120为什么不能在iPad 3上运行?

says that OpenGL ES 2.0 uses GLSL 1.20. So why doesn't #version 120 work on the iPad 3?

推荐答案

您是否尝试过自行移调?这是性能问题吗?如果没有，我会尝试一下，因为这是优化程序应该处理的事情，它将花费两分钟.像这样:

Have you tried just transposing it yourself? Is it a performance problem? If not, I would try it because it's something the optimizer should handle and it will take two minutes. Something like:

highp mat4 transpose(in highp mat4 inMatrix) {
    highp vec4 i0 = inMatrix[0];
    highp vec4 i1 = inMatrix[1];
    highp vec4 i2 = inMatrix[2];
    highp vec4 i3 = inMatrix[3];

    highp mat4 outMatrix = mat4(
                 vec4(i0.x, i1.x, i2.x, i3.x),
                 vec4(i0.y, i1.y, i2.y, i3.y),
                 vec4(i0.z, i1.z, i2.z, i3.z),
                 vec4(i0.w, i1.w, i2.w, i3.w)
                 );

    return outMatrix;
}

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