GLSL幾個要點(diǎn)

限定符

在之前的博客中也提到了，GLSL中的限定符號主要有：

attritude：一般用于各個頂點(diǎn)各不相同的量。如頂點(diǎn)顏色、坐標(biāo)等。? 輸入

uniform：一般用于對于3D物體中所有頂點(diǎn)都相同的量。比如光源位置，統(tǒng)一變換矩陣等。

varying：表示易變量，一般用于頂點(diǎn)著色器傳遞到片元著色器的量。輸出，vetexshader和fragshader數(shù)據(jù)的傳遞

const：常量。

privatestaticfinalStringVERTEX_SHADER="attribute vec4 position;\n"+

"attribute vec4 inputTextureCoordinate;\n"+

"attribute vec4 inputTextureCoordinate2;\n"+

"\n"+

"varying vec2 textureCoordinate;\n"+

"varying vec2 textureCoordinate2;\n"+

"\n"+

"void main()\n"+

"{\n"+

" gl_Position = position;\n"+

" textureCoordinate = inputTextureCoordinate.xy;\n"+

" textureCoordinate2 = inputTextureCoordinate2.xy;\n"+

"}";

publicstaticfinalStringALPHA_BLEND_FRAGMENT_SHADER="varying highp vec2 textureCoordinate;\n"+

" varying highp vec2 textureCoordinate2;\n"+

"\n"+

" uniform sampler2D inputImageTexture;\n"+

" uniform sampler2D inputImageTexture2;\n"+

"\n"+

" uniform lowp float mixturePercent;\n"+

"\n"+

" void main()\n"+

" {\n"+

" lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);\n"+

" lowp vec4 textureColor2 = texture2D(inputImageTexture2, textureCoordinate2);\n"+

"\n"+

" gl_FragColor = vec4(mix(textureColor.rgb, textureColor2.rgb, textureColor2.a * mixturePercent), textureColor.a);\n"+

" }";

以上是一個典型的頂點(diǎn)著色器和片段著色器

inputTextureCoordinatetextureCoordinate2 頂點(diǎn)傳入?

position? 綁定頂點(diǎn)坐標(biāo)

inputImageTexture

inputImageTexture2? 創(chuàng)建并綁定紋理

inputTextureCoordinate?

inputTextureCoordinate2綁定紋理坐標(biāo)

textureCoordinate2作為片段著色器的輸出? 最終生成gl_FragColor

對于抖音特效，其實(shí)就改變gl_Position 和?gl_FragColor