adjust light functionality,

bugs:
- background cannot be changed during runtime

QtMeshViewer/Resources/Resources.qrc

@@ -19,5 +19,6 @@
         <file>Z.png</file>
         <file>screenshot.png</file>
         <file>wireframe.png</file>
+        <file>light.png</file>
     </qresource>
 </RCC>

QtMeshViewer/Resources/about.txt

@@ -8,6 +8,7 @@ left mouse - rotate
 right mouse - move
 scroll - zoom
 space - reset view
+L - set light to current position
 esc - close
 
 using the X, Y, Z Button you can activate/deactivate the rotating directions

QtMeshViewer/Resources/fshader.glsl

@@ -15,40 +15,41 @@ uniform struct Light {
 uniform bool b_transparent;
 uniform bool b_light;
 
-varying vec2 v_texcoord;
-varying vec3 v_position;
-varying vec3 v_normal;
+varying vec2 v_surfaceUV;
+varying vec3 v_surfacePosition;
+varying vec3 v_surfaceNormal;
 
 void main()
 {
 	// variables
-	float brightness;
-
-	if(b_light == true)
-	{
-		// calculate normals in worldspace
-		vec3 normal = normalize(n_matrix * v_normal);
-
-		//get the surface - light vector (cause this is a candel)
-		vec3 surfaceToLight = light.position - v_position;
-
-		// calculate the brightness depending on the angle
-		brightness = dot(normal, surfaceToLight) / (length(surfaceToLight) * length(normal));
-		brightness = clamp(brightness, 0, 1);
-	}
-	else
-	{
-		brightness = 1;
-		light.intensities = vec3(1,1,1);
-	}
+	vec3 diffuse;
 
 	// get fragment color from texture
-	vec4 surfaceColor = vec4(texture2D(texture, v_texcoord));
+	vec4 surfaceColor = vec4(texture2D(texture, v_surfaceUV));
 
 	// if not transparent, ignore alpha value and set it to 1
 	if(!b_transparent)
 		surfaceColor.a = 1.0f;
 
-	// pass the data to ogl
-	gl_FragColor = vec4(brightness * light.intensities * surfaceColor.rgb, surfaceColor.a);
+	if(b_light)
+	{
+		// calculate normals in worldspace
+		vec3 normalWorld = normalize(n_matrix * v_surfaceNormal);
+
+		//get the surface - light vector (cause this is a point light)
+		vec3 surfaceToLight = normalize(light.position - v_surfacePosition);
+
+		// calculate the brightness depending on the angle
+		float diffuseCoefficient = max(0.0, dot(normalWorld, surfaceToLight));
+
+		// result diffuse color
+		diffuse = diffuseCoefficient * surfaceColor.rgb * light.intensities;
+	}
+	else
+	{
+		diffuse = surfaceColor.rgb;
+	}
+
+	// put all together
+	gl_FragColor = vec4(diffuse, surfaceColor.a);
 }

QtMeshViewer/Resources/vshader.glsl

@@ -12,9 +12,9 @@ attribute vec4 a_position;
 attribute vec2 a_texcoord;
 attribute vec3 a_normal;
 
-varying vec2 v_texcoord;
-varying vec3 v_position;
-varying vec3 v_normal;
+varying vec2 v_surfaceUV;
+varying vec3 v_surfacePosition;
+varying vec3 v_surfaceNormal;
 
 void main()
 {
@@ -23,7 +23,7 @@ void main()
 
 	// Pass data to fragment shader
 	// Value will be automatically interpolated to fragments inside polygon faces
-	v_texcoord = a_texcoord;
-	v_position = vec3(norm_matrix * m_matrix * a_position);
-	v_normal = a_normal;
+	v_surfaceUV = a_texcoord;
+	v_surfacePosition = vec3(norm_matrix * m_matrix * a_position);
+	v_surfaceNormal = a_normal;
 }