Fragment Shaders

The fragment shader is called from every pixel in the primitives drawn to the screen.

141                 // The fragment shader can be thought of for now as doing per pixel computations. It is the
142                 // fragment shader the colors each pixel in a 3d scene.
143                 var fragmentShaderSource = "precision mediump float;"
144                                            + ""
145                                            + "void main()"
146                                            + "{"
147                                            + "    gl_FragColor = vec4(0.8,0.3,0.3,1);"
148                                            + "}";

(0,1)

(-1,-1) (1,-1)

The output of the fragment shader is the 4-vector gl_FragColor containing the r,g,b,α color of the pixel. This example sets a constant color. Later examples will show how to pass variables into the fragment shader and use them to compute the color.

Fragment Shaders

Notes