calculate normal matrix once in cpp (performance),

added bool variable to turn light on/off (still needs button),

QtMeshViewer/Header/OglViewerWidget.h

@@ -38,7 +38,7 @@ private:
 	} m_rotDirections;
 
 	struct {
-		QVector3D position = { 1,1,1 };
+		QVector3D position = { 10,10,10 };
 		QVector3D intensities = { 1,0.25,0.25 };
 	} m_light;
 
@@ -50,6 +50,7 @@ private:
 	QQuaternion m_rotation;
 
 	bool m_wireframe = false;
+	bool m_lightOn = true;
 
 protected:
 	void mousePressEvent(QMouseEvent *e) Q_DECL_OVERRIDE;

QtMeshViewer/Resources/fshader.glsl

@@ -4,10 +4,8 @@ precision mediump int;
 precision mediump float;
 #endif
 
-//uniform mat3 n_matrix;
+uniform mat3 n_matrix;
 uniform sampler2D texture;
-uniform mat4 norm_matrix;
-uniform mat4 m_matrix;
 
 uniform struct Light {
 	vec3 position;
@@ -15,6 +13,7 @@ uniform struct Light {
 } light;
 
 uniform bool b_transparent;
+uniform bool b_light;
 
 varying vec2 v_texcoord;
 varying vec3 v_position;
@@ -22,21 +21,34 @@ varying vec3 v_normal;
 
 void main()
 {
-	mat3 n_matrix = transpose(inverse(mat3(norm_matrix * m_matrix)));
-	vec3 normal = normalize(n_matrix * v_normal);
+	// variables
+	float brightness;
 
-	vec3 surfaceToLight = light.position - v_position;
+	if(b_light == true)
+	{
+		// calculate normals in worldspace
+		vec3 normal = normalize(n_matrix * v_normal);
 
-	float brightness = dot(normal, surfaceToLight) / (length(surfaceToLight) * length(normal));
-	brightness = clamp(brightness, 0, 1);
+		//get the surface - light vector (cause this is a candel)
+		vec3 surfaceToLight = light.position - v_position;
 
-	// Set fragment color from texture
+		// 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);
+	}
+
+	// get fragment color from texture
 	vec4 surfaceColor = vec4(texture2D(texture, v_texcoord));
 
+	// 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);
 }

QtMeshViewer/Source/GeometryEngine.cpp

@@ -191,6 +191,9 @@ void GeometryEngine::drawGeometry(QOpenGLShaderProgram *program, bool wireframe)
 		// Set model matrix
 		program->setUniformValue("m_matrix", it.modelMatrix);
 
+		// Set normal matrix
+		program->setUniformValue("n_matrix", (normMatrix * it.modelMatrix).normalMatrix());
+
 		// decide if this is transparent
 		program->setUniformValue("b_transparent", tmp_transparent);
 

QtMeshViewer/Source/OglViewerWidget.cpp

@@ -226,7 +226,8 @@ void OglViewerWidget::paintGL()
 	// Set view-projection matrix
 	m_program.setUniformValue("vp_matrix", m_projection * view);
 
-	// Set Light
+	// Set Light values
+	m_program.setUniformValue("b_light", m_lightOn);
 	m_program.setUniformValue("light.position", m_light.position);
 	m_program.setUniformValue("light.intensities", m_light.intensities);