gistfile1.txt

    /**
     * Generates a frame of data using GL commands.
     */
    private void generateSurfaceFrame(int frameIndex) {
        frameIndex %= 8;
        int startX, startY;
        if (frameIndex < 4) {
            // (0,0) is bottom-left in GL
            startX = frameIndex * (mWidth / 4);
            startY = mHeight / 2;
        } else {
            startX = (7 - frameIndex) * (mWidth / 4);
            startY = 0;
        }
        GLES20.glDisable(GLES20.GL_SCISSOR_TEST);
        GLES20.glClearColor(TEST_R0 / 255.0f, TEST_G0 / 255.0f, TEST_B0 / 255.0f, 1.0f);
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
        GLES20.glEnable(GLES20.GL_SCISSOR_TEST);
        GLES20.glScissor(startX, startY, mWidth / 4, mHeight / 2);
        GLES20.glClearColor(TEST_R1 / 255.0f, TEST_G1 / 255.0f, TEST_B1 / 255.0f, 1.0f);
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
    }