Shaders: pass normal matrix the right way.

Besides that this was long overdue, GLSL ES doesn't have mat3x3().

src/Shaders/PhongShader.cpp

@@ -58,6 +58,7 @@ PhongShader::PhongShader() {
     shininessUniform = uniformLocation("shininess");
     transformationMatrixUniform = uniformLocation("transformationMatrix");
     projectionMatrixUniform = uniformLocation("projectionMatrix");
+    normalMatrixUniform = uniformLocation("normalMatrix");
     lightUniform = uniformLocation("light");
     lightColorUniform = uniformLocation("lightColor");
 

src/Shaders/PhongShader.h

@@ -84,11 +84,12 @@ class SHADERS_EXPORT PhongShader: public AbstractShaderProgram {
         }
 
         /**
-         * @brief Set transformation matrix
+         * @brief Set transformation matrix and normal matrix
          * @return Pointer to self (for method chaining)
          */
         inline PhongShader* setTransformation(const Matrix4& matrix) {
             setUniform(transformationMatrixUniform, matrix);
+            setUniform(normalMatrixUniform, matrix.rotation());
             return this;
         }
 
@@ -128,6 +129,7 @@ class SHADERS_EXPORT PhongShader: public AbstractShaderProgram {
             shininessUniform,
             transformationMatrixUniform,
             projectionMatrixUniform,
+            normalMatrixUniform,
             lightUniform,
             lightColorUniform;
 };

src/Shaders/PhongShader.vert

@@ -5,6 +5,7 @@
 
 uniform highp mat4 transformationMatrix;
 uniform highp mat4 projectionMatrix;
+uniform mediump mat3 normalMatrix;
 uniform highp vec3 light;
 
 #ifdef EXPLICIT_ATTRIB_LOCATION
@@ -25,7 +26,7 @@ void main() {
     highp vec3 transformedPosition = transformedPosition4.xyz/transformedPosition4.w;
 
     /* Transformed normal vector */
-    transformedNormal = normalize(mat3x3(transformationMatrix)*normal);
+    transformedNormal = normalMatrix*normal;
 
     /* Direction to the light */
     lightDirection = normalize(light - transformedPosition);