// __multiversion__ // this signals the loading code to prepend either #version 100 or #version 300 es as apropriate. // to use centroid sampling we need to have version 300 es shaders, which requires changing: // attribute to in // varying to out when in vertex shaders or in when in fragment shaders // defining an out vec4 fragcolor and replacing uses of gl_fragcolor with fragcolor // texture2d to texture #if __version__ >= 300 // version 300 code #define varying in #define texture2d texture

```glsl // __multiversion__ // This signals the loading code to prepend either #version 100 or #version 300 es as appropriate. // To use centroid sampling, we need to have version 300 es shaders, which requires some changes: // - Change 'attribute' to 'in' // - Change 'varying' to 'out' in vertex shaders and 'in' in fragment shaders // - Define an 'out vec4 fragColor' and replace uses of 'gl_FragColor' with 'fragColor' // - Change 'texture2D' to 'texture' #if __version__ >= 300 // Version 300 ES code #define attribute in #define varying in #define texture2D texture // Define the output color for the fragment shader out vec4 fragColor; #else // Version 100 ES code varying vec2 vTexCoord; #endif void main() { // Example: Sample a texture and set the fragment color vec4 color = texture2D(uTexture, vTexCoord); // Set the final fragment color fragColor = color; } ``` 需要注意的逻辑点： 1. 版本兼容性：确保在不同版本的 GLSL 中正确处理变量和函数的定义，避免编译错误。 2. 纹理采样：在 `texture2D` 和 `texture` 之间进行正确的转换，确保纹理采样正确无误。 3. 输出颜色：在版本 300 ES 中，使用 `out vec4 fragColor` 替代 `gl_FragColor`，确保颜色输出正确。 [2024-12-14 17:34:20 | AI写代码神器 | 356点数解答]