adjust light functionality,

bugs:
- background cannot be changed during runtime

QtMeshViewer/Header/OglViewerWidget.h

@@ -38,7 +38,7 @@ private:
 	} m_rotDirections;
 
 	struct {
-		QVector3D position = { 10,10,10 };
+		QVector3D position = { 1,1,1 };
 		QVector3D intensities = { 1,0.25,0.25 };
 	} m_light;
 
@@ -50,7 +50,7 @@ private:
 	QQuaternion m_rotation;
 
 	bool m_wireframe = false;
-	bool m_lightOn = true;
+	bool m_lightOn = false;
 
 protected:
 	void mousePressEvent(QMouseEvent *e) Q_DECL_OVERRIDE;
@@ -68,6 +68,7 @@ protected:
 private:
 	void initShaders();
 	void setConnections();
+	void updateLightPosition();
 
 private slots:
 	void resetView();
@@ -75,5 +76,6 @@ private slots:
 public slots:
 	void changeDirection(int direction);
 	void toggleWireframe();
+	void toggleLight();
 };
 

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;
+	vec3 diffuse;
 
-	if(b_light == true)
+	// get fragment color from texture
+	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;
+
+	if(b_light)
 	{
 		// calculate normals in worldspace
-		vec3 normal = normalize(n_matrix * v_normal);
+		vec3 normalWorld = normalize(n_matrix * v_surfaceNormal);
 
-		//get the surface - light vector (cause this is a candel)
-		vec3 surfaceToLight = light.position - v_position;
+		//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
-		brightness = dot(normal, surfaceToLight) / (length(surfaceToLight) * length(normal));
-		brightness = clamp(brightness, 0, 1);
+		float diffuseCoefficient = max(0.0, dot(normalWorld, surfaceToLight));
+
+		// result diffuse color
+		diffuse = diffuseCoefficient * surfaceColor.rgb * light.intensities;
 	}
 	else
 	{
-		brightness = 1;
-		light.intensities = vec3(1,1,1);
+		diffuse = surfaceColor.rgb;
 	}
 
-	// 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);
+	// 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;
 }

QtMeshViewer/Source/MainWindow.cpp

@@ -101,6 +101,12 @@ void MainWindow::setupWidgets()
 	connect(wireframe, &QAction::triggered, viewer, &OglViewerWidget::toggleWireframe);
 	ui->mainToolBar->addAction(wireframe);
 
+	QAction *light = new QAction(QIcon(":/images/toolbar/light.png"), "Light", this);
+	light->setCheckable(true);
+	light->setChecked(false);
+	connect(light, &QAction::triggered, viewer, &OglViewerWidget::toggleLight);
+	ui->mainToolBar->addAction(light);
+
 	ui->mainToolBar->addSeparator();
 
 	QAction *fileInfo = new QAction(QIcon(":/images/toolbar/info.png"), "File info", this);

QtMeshViewer/Source/OglViewerWidget.cpp

@@ -173,14 +173,18 @@ void OglViewerWidget::keyPressEvent(QKeyEvent *e)
 	{
 		parentWidget()->close();
 	}
+	else if (e->key() == Qt::Key_L)
+	{
+		updateLightPosition();
+		update();
+	}
 }
 
 void OglViewerWidget::initializeGL()
 {
 	initializeOpenGLFunctions();
 
-	//glClearColor(0.5000f, 0.8000f, 1.0000f, 0.0000f);
-	glClearColor(0.02f, 0.01f, 0.01f, 0.0000f);
+	glClearColor(0.5000f, 0.8000f, 1.0000f, 0.0000f);
 
 	initShaders();
 
@@ -269,6 +273,13 @@ void OglViewerWidget::setConnections()
 
 }
 
+void OglViewerWidget::updateLightPosition()
+{
+	QMatrix4x4 rotateBack;
+	rotateBack.rotate(m_rotation.inverted());
+	m_light.position = rotateBack * (-m_translation);
+}
+
 
 /////////////////////////////////////////////////////////////////////////
 // private slots
@@ -305,3 +316,21 @@ void OglViewerWidget::toggleWireframe()
 	m_wireframe = 1 - m_wireframe;
 	update();
 }
+
+void OglViewerWidget::toggleLight()
+{
+	m_lightOn = 1 - m_lightOn;
+
+	if (m_lightOn)
+	{
+		glClearColor(m_light.intensities.x() / 100, m_light.intensities.y() / 100, m_light.intensities.z() / 100, 0.0000f);
+
+		updateLightPosition();
+	}
+	else
+	{
+		glClearColor(0.5000f, 0.8000f, 1.0000f, 0.0000f);
+	}
+
+	update();
+}