Mali GPU User Interface Engine Application Development Guide

Tutorial on Drawing 3D Shapescube_reflection_mapping.vertThe vertex code in Example 4-44 calculates the view vector based on thenormal and the camera view:Example 4-44 cube_reflection_mapping.vert shader for cube mappinguniform mat4 WORLD_VIEW_PROJECTION;uniform mat3 WORLD;uniform vec3 CAMERA_POSITION;attribute vec4 POSITION;attribute vec3 NORMAL;varying vec3 vNormal;varying vec3 vViewVector;void main(void){gl_Position = WORLD_VIEW_PROJECTION * POSITION;// multiply the normal by the model matrix so that the teapot can// be rotatedvNormal = WORLD * NORMAL;vViewVector = CAMERA_POSITION - (WORLD * POSITION.xyz);}cube_reflection_mapping.fragThe code in Example 4-45 uses the normal vector to copy the cube map valuesto the teapot surface. This creates a mirror effect.Example 4-45 cube_reflection_mapping.frag shader for cube mappinguniform samplerCube environmentCubeMap;varying vec3 vNormal;varying vec3 vViewVector;void main(void){// normalize the normals as the interpolation changes their lengthvec3 normal = normalize(vNormal);vec3 viewVector = normalize(vViewVector);vec3 reflectionVector = reflect(-viewVector, normal);gl_FragColor = textureCube(environmentCubeMap,reflectionVector.xyz);}4. Example 4-46 shows the vertexDeclaration code. The coordinates for the skybox areentered manually:Example 4-46 Load the assets and set the skybox parameters...// Set up position data and index data of the skybox manuallyGLfloat vertexData[] ={-0.5f, -0.5f, -0.5f, // 00.5f, -0.5f, -0.5f, // 1ARM DUI 0527A-02a Copyright © 2010 ARM. All rights reserved. 4-36ID070710Non-Confidential - Draft - Beta