1 //A simple shader that applies diffuse lighting to a mono-coloured object.
3 attribute highp vec3 aPosition;
4 attribute highp vec2 aTexCoord;
5 attribute highp vec3 aNormal;
6 varying mediump vec3 vIllumination;
7 uniform mediump vec3 uSize;
8 uniform mediump vec3 uObjectDimensions;
9 uniform mediump mat4 uMvpMatrix;
10 uniform mediump mat4 uModelView;
11 uniform mediump mat4 uViewMatrix;
12 uniform mediump mat3 uNormalMatrix;
13 uniform mediump mat4 uObjectMatrix;
14 uniform mediump vec3 lightPosition;
15 uniform mediump vec2 uStageOffset;
17 //Visual size and offset
18 uniform mediump vec2 offset;
19 uniform mediump vec2 size;
20 uniform mediump vec4 offsetSizeMode;
21 uniform mediump vec2 origin;
22 uniform mediump vec2 anchorPoint;
24 vec4 ComputeVertexPosition()
26 vec2 visualSize = mix(uSize.xy*size, size, offsetSizeMode.zw );
27 float scaleFactor = min( visualSize.x / uObjectDimensions.x, visualSize.y / uObjectDimensions.y );
28 vec3 originFlipY =vec3(origin.x, -origin.y, 0.0);
29 vec3 anchorPointFlipY = vec3( anchorPoint.x, -anchorPoint.y, 0.0);
30 vec3 visualOffset = vec3( offset * offsetSizeMode.xy + offset * uSize.xy * (1.0-offsetSizeMode.xy), 0.0) * vec3(1.0,-1.0,1.0);
32 return vec4( (aPosition + anchorPointFlipY)*scaleFactor + visualOffset + originFlipY * uSize, 1.0 );
37 vec4 normalisedVertexPosition = ComputeVertexPosition();
38 vec4 vertexPosition = uObjectMatrix * normalisedVertexPosition;
39 vertexPosition = uMvpMatrix * vertexPosition;
41 //Illumination in Model-View space - Transform attributes and uniforms
42 vec4 mvVertexPosition = uModelView * normalisedVertexPosition;
43 vec3 normal = uNormalMatrix * mat3( uObjectMatrix ) * aNormal;
45 vec4 mvLightPosition = vec4( ( lightPosition.xy - uStageOffset ), lightPosition.z, 1.0 );
46 mvLightPosition = uViewMatrix * mvLightPosition;
47 vec3 vectorToLight = normalize( mvLightPosition.xyz - mvVertexPosition.xyz );
49 float lightDiffuse = max( dot( vectorToLight, normal ), 0.0 );
50 vIllumination = vec3( lightDiffuse * 0.5 + 0.5 );
52 gl_Position = vertexPosition;