René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"无效的GLSL","articleBody":"还有片元着色器中的一段代码和上边的一个rect数组，能麻烦解释下是干什么用的吗？我注释掉也没什么问题。\r\n\r\n\r\n#extension GL_OES_EGL_image_external : require\r\nprecision mediump float;\r\n\r\n\r\nstruct Rect {\r\n    vec4 color;\r\n    float left;\r\n    float top;\r\n    float right;\r\n    float bottom;\r\n};\r\n\r\n\r\n// important to include in order to use rendered Android View to gl texture\r\nuniform samplerExternalOES u_Texture;\r\n\r\nuniform float u_GlobalTime;\r\n\r\n\r\n//const int MAX_RECTS = 4;\r\n//uniform Rect u_Rects[MAX_RECTS];\r\n\r\nvarying vec2 v_TexCoordinate;\r\n\r\nvoid main()\r\n{\r\n\r\n    vec2 uv = v_TexCoordinate.xy;\r\n\r\n    vec4 primary_color = texture2D(u_Texture, uv);\r\n\r\n//    vec4 tmpColor = vec4(0.0, 0.0, 0.0, 0.0);\r\n//\r\n//    bool set = false;\r\n//\r\n//    for(int idx = 0; idx \u003c MAX_RECTS; idx++) {\r\n//        if(uv.x \u003e u_Rects[idx].left \u0026\u0026 uv.x \u003c u_Rects[idx].right \u0026\u0026 uv.y \u003e u_Rects[idx].top \u0026\u0026 uv.y \u003c u_Rects[idx].bottom) {\r\n//            tmpColor += u_Rects[idx].color;\r\n//            set = true;\r\n//        }\r\n//    }\r\n//\r\n//    if(set) {\r\n//        primary_color *= tmpColor;\r\n//    }\r\n\r\n    gl_FragColor = primary_color;\r\n}","author":{"url":"https://github.com/Chen-Alexander","@type":"Person","name":"Chen-Alexander"},"datePublished":"2021-07-20T15:47:32.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/2/AndroidOpenGLView/issues/2"}