双三次插值算法的OpenGL实现

转自：http://blog.csdn.net/jxt1234and2010

双三次插值算法的OpenGL实现

说明

最近写一个图像缩放的接口，考虑到自己有现成的OpenGL图像处理引擎，还是直接写shader用GPU实现方便。为了效果好一些，采用了双三次插值算法。 
算法相关公式可参考这篇文章： 
http://blog.csdn.net/lichengyu/article/details/8526629

代码

详细实现代码见： 
https://github.com/jxt1234/Simple3D/blob/master/src/GL/GLBicubicWork.cpp 
测试代码见： 
https://github.com/jxt1234/Simple3D/blob/master/gltest/GLBitmapWorkTest.cpp

要集成到其他项目中，只需要 vertex shader 和 fragment shader 两部分的代码，毕竟不同的图像引擎在如何加载shader，如何传参数，如何上传纹理的逻辑都是不同的。

bicubic.vex

<code class="hljs glsl has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">attribute</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec4</span> pos;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">attribute</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span> tex;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">varying</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span> vTex;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> main(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)
{
    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">gl_Position</span> = pos;
    vTex = tex;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>

生成的 fragment shader： 
bicubic.fra

<code class="hljs glsl has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#ifdef GL_ES</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">precision</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">mediump</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>;<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//用于手机上时需要添加此句</span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#endif</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">varying</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span> vTex;<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//纹理坐标，注意与 vertex shader 中的变量对应</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">uniform</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">sampler2D</span> buffer;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">uniform</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> uUnit;<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//传入原图的宽</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">uniform</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> vUnit;<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//传入原图的高</span>

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> BiCubicPoly1(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> x, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> a)
{
    x = <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">abs</span>(x);
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> res = (a+<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>))*x*x*x - (a+<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>))*x*x + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>);
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> res;
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> BiCubicPoly2(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> x, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> a)
{
    x = <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">abs</span>(x);
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> res = a*x*x*x - <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>)*a*x*x + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>)*a*x - <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>)*a;
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> res;
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> main()
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span> basic; 
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span> det; 
basic = vTex*<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit) - <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>); 
det = <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">fract</span>(basic); 
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">gl_FragColor</span> = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec4</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.0</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.0</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.0</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.0</span>)
+BiCubicPoly2(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly2(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly2(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly1(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly2(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly1(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly2(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly2(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly1(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly2(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly1(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly1(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly1(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly1(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly1(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly2(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly1(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly2(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly1(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly1(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly1(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly1(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly1(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly2(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly2(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly2(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly2(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly1(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly2(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly1(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
+BiCubicPoly2(det.x-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*BiCubicPoly2(det.y-<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>))*<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">texture2D</span>(buffer, vTex + ( - det + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>)))/<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">vec2</span>(uUnit, vUnit))
;
}</code>