小编fra*_*sig的帖子

所以我在屏幕的某个……嗯……点上绘制一个点，然后该点四处移动。我的顶点着色器看起来像这样。

private final String vertexShaderCode =
     "attribute vec4 vPosition;" +
                "uniform mat4 Projection; \n" +
                "uniform mat4 ModelView; \n" +
                "void main() {" +
                        "  gl_Position = Projection * ModelView * vPosition;" +
                        "  gl_PointSize = 900.0; " +
                        "}"; 

我想要实现的是围绕这个顶点的位置渲染一个圆。为此，我使用片段着色器：

 private final String fragmentShaderCode =
        "precision highp float; \n" +
                "uniform vec2 aCirclePosition; \n" +
                "uniform float aRadius; \n" +
                "uniform vec4 aColor; \n" +
                "const float threshold = 0.3;\n" +
                "void main() \n" +
                "{ \n" +
                " …