Remove normal depth

Scaling normal depth (y axis) makes disappear the specular of
fragments... So I think it can be removed, it is not a very
useful/important attribute.

src/models.c

@@ -756,7 +756,6 @@ Material LoadDefaultMaterial(void)
     material.colSpecular = WHITE;   // Specular color
     
     material.glossiness = 100.0f;   // Glossiness level
-    material.normalDepth = 1.0f;    // Normal map depth
     
     return material;
 }

src/raylib.h

@@ -419,7 +419,6 @@ typedef struct Material {
     Color colSpecular;          // Specular color
     
     float glossiness;           // Glossiness level (Ranges from 0 to 1000)
-    float normalDepth;          // Normal map depth
 } Material;
 
 // Model type

src/rlgl.c

@@ -1816,9 +1816,6 @@ void rlglDrawMesh(Mesh mesh, Material material, Matrix transform)
         glActiveTexture(GL_TEXTURE1);
         glBindTexture(GL_TEXTURE_2D, material.texNormal.id);
         glUniform1i(material.shader.mapTexture1Loc, 1);     // Normal texture fits in active texture unit 1
-        
-        // TODO: Upload to shader normalDepth
-        //glUniform1f(???, material.normalDepth);
     }
     
     if ((material.texSpecular.id != 0) && (material.shader.mapTexture2Loc != -1))
@@ -2565,7 +2562,7 @@ static Shader LoadDefaultShader(void)
 // Load standard shader
 // NOTE: This shader supports: 
 //      - Up to 3 different maps: diffuse, normal, specular
-//      - Material properties: colAmbient, colDiffuse, colSpecular, glossiness, normalDepth
+//      - Material properties: colAmbient, colDiffuse, colSpecular, glossiness
 //      - Up to 8 lights: Point, Directional or Spot
 static Shader LoadStandardShader(void)
 {

src/rlgl.h

@@ -207,7 +207,6 @@ typedef enum { OPENGL_11 = 1, OPENGL_33, OPENGL_ES_20 } GlVersion;
         Color colSpecular;          // Specular color
         
         float glossiness;           // Glossiness level (Ranges from 0 to 1000)
-        float normalDepth;          // Normal map depth
     } Material;
     
     // Light type