PhongShader: using `position` for vertex position.

src/Shaders/PhongShader.vert

@@ -2,7 +2,7 @@ uniform mat4 transformationMatrix;
 uniform mat4 projectionMatrix;
 uniform vec3 light;
 
-layout(location = 0) in vec4 vertex;
+layout(location = 0) in vec4 position;
 layout(location = 1) in vec3 normal;
 
 out vec3 transformedNormal;
@@ -11,18 +11,18 @@ out vec3 cameraDirection;
 
 void main() {
     /* Transformed vertex position */
-    vec4 transformedVertex4 = transformationMatrix*vertex;
-    vec3 transformedVertex = transformedVertex4.xyz/transformedVertex4.w;
+    vec4 transformedPosition4 = transformationMatrix*position;
+    vec3 transformedPosition = transformedPosition4.xyz/transformedPosition4.w;
 
     /* Transformed normal vector */
     transformedNormal = normalize(mat3x3(transformationMatrix)*normal);
 
     /* Direction to the light */
-    lightDirection = normalize(light - transformedVertex);
+    lightDirection = normalize(light - transformedPosition);
 
     /* Direction to the camera */
-    cameraDirection = -transformedVertex;
+    cameraDirection = -transformedPosition;
 
-    /* Transform the vertex */
-    gl_Position = projectionMatrix*transformedVertex4;
+    /* Transform the position */
+    gl_Position = projectionMatrix*transformedPosition4;
 }