Shader based shadow mapping

[poo2thegeek]

I am trying to dynamically draw shadows on a scene I have created.
At current I am using code that I have copied directly from a C++ shadow drawing program into LWJGL. http://www.fabiensanglard.net/shadowmapping/

However, it does not seemed to have worked.
I create the program by creating a new instance of "ShadowProjection2":

WIDTH = 1024;
		HEIGHT = 1024;
		
		//GLfloat borderColor[4] = {0,0,0,0};
				
		// Try to use a texture depth component
		textureID = glGenTextures();
		glBindTexture(GL_TEXTURE_2D, textureID);
		
		// GL_LINEAR does not make sense for depth texture. However, next tutorial shows usage of GL_LINEAR and PCF
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
		
		// Remove artefact on the edges of the shadowmap
		glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP );
		glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP );
		
		//glTexParameterfv( GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderColor );
		
		
		
		// No need to force GL_DEPTH_COMPONENT24, drivers usually give you the max precision if available 
		glTexImage2D( GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, WIDTH, HEIGHT, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, (FloatBuffer)null);
		glBindTexture(GL_TEXTURE_2D, 0);
		
		// create a framebuffer object
		fboID = glGenFramebuffers();
		glBindFramebuffer(GL_FRAMEBUFFER, fboID);
		
		// Instruct openGL that we won't bind a color texture with the currently binded FBO
		
		glDrawBuffer(GL_NONE);
		glReadBuffer(GL_NONE);
		
		// attach the texture to FBO depth attachment point
		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,GL_TEXTURE_2D, textureID, 0);
		// check FBO status
		if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
			System.err.println("GL_FRAMEBUFFER_COMPLETE_EXT failed, CANNOT use FBO\n");
		
		// switch back to window-system-provided framebuffer
		glBindFramebuffer(GL_FRAMEBUFFER, 0);
		
		shadow = AgeOfCivilisation.get().resources().getShader("shadow");
		try{
			shadow.load();
		}catch(Exception e){
			Log.getInstance().log(e);
		}

to render the code I have directly copied the initial source code:

public void drawShadow(PlayerCamera camera){
		
		glBindFramebuffer(GL_FRAMEBUFFER, fboID);
		GL20.glUseProgram(0);
		glViewport(0,0, WIDTH, HEIGHT);
		glClear(GL_DEPTH_BUFFER_BIT);
		glColorMask(false,false,false,false);
		setupMatrices(p_light[0],p_light[1],p_light[2],l_light[0],l_light[1],l_light[2]);
		//glCullFace(GL_FRONT);
		drawObjects();
		setTextureMatrix();
		
		
		glBindFramebuffer(GL_FRAMEBUFFER,0);
		
		glViewport(0,0,Display.getWidth(), Display.getHeight());
		
		glColorMask(true,true,true,true);
		//glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		
		shadow.bind();
		shadow.sendInt("ShadowMap", 7);
		GL13.glActiveTexture(GL13.GL_TEXTURE7);
		glBindTexture(GL_TEXTURE_2D, textureID);
		
		setupMatrices(p_camera[0],p_camera[1],p_camera[2],l_camera[0],l_camera[1],l_camera[2]);
		//glCullFace(GL_BACK);
		drawObjects();
		
		GL20.glUseProgram(0);
		 glMatrixMode(GL_PROJECTION);
		 glLoadIdentity();
		 glOrtho(-Display.getWidth()/2,Display.getWidth()/2,-Display.getHeight()/2,Display.getHeight()/2,1,20);
		 glMatrixMode(GL_MODELVIEW);
		 glLoadIdentity();
		 glColor4f(1,1,1,1);
		 GL13.glActiveTexture(GL13.GL_TEXTURE0);
		 glBindTexture(GL_TEXTURE_2D,textureID);
		 glEnable(GL_TEXTURE_2D);
		 glTranslated(0,0,-1);
		 glBegin(GL_QUADS);
		 glTexCoord2d(0,0);glVertex3f(0,0,0);
		 glTexCoord2d(1,0);glVertex3f(Display.getWidth()/2,0,0);
		 glTexCoord2d(1,1);glVertex3f(Display.getWidth()/2,Display.getHeight()/2,0);
		 glTexCoord2d(0,1);glVertex3f(0,Display.getHeight()/2,0);
		 
		 
		 glEnd();
		 glDisable(GL_TEXTURE_2D);
	}
	
public void setTextureMatrix(){
		FloatBuffer modelView = BufferUtils.createFloatBuffer(16);
		FloatBuffer projection = BufferUtils.createFloatBuffer(16);

		// Moving from unit cube [-1,1] to [0,1]  
		float[] bias_ = {	
				0.5f, 0.0f, 0.0f, 0.0f, 
				0.0f, 0.5f, 0.0f, 0.0f,
				0.0f, 0.0f, 0.5f, 0.0f,
				0.5f, 0.5f, 0.5f, 1.0f};

		FloatBuffer bias = (FloatBuffer) BufferUtils.createFloatBuffer(16).put(bias_).flip();

		// Grab modelview and transformation matrices
		glGetFloat(GL_MODELVIEW_MATRIX, modelView);
		glGetFloat(GL_PROJECTION_MATRIX, projection);
		
		//modelView.flip().limit(16);
		//projection.flip().limit(16);
		
		//modelView.flip();
		//projection.flip();

		glMatrixMode(GL_TEXTURE);
		GL13.glActiveTexture(GL13.GL_TEXTURE7);

		glLoadIdentity();
		GL11.glLoadMatrix(bias);
		GL11.glMultMatrix(projection);
		GL11.glMultMatrix(modelView);

		// Go back to normal matrix mode
		glMatrixMode(GL_MODELVIEW);
	}

	private void setupMatrices(float position_x,float position_y,float position_z,float lookAt_x,float lookAt_y,float lookAt_z){
		glMatrixMode(GL_PROJECTION);
		glLoadIdentity();
		GLU.gluPerspective(45,WIDTH/(float)HEIGHT,10,40000);
		glMatrixMode(GL_MODELVIEW);
		glLoadIdentity();
		GLU.gluLookAt(position_x,position_y,position_z,lookAt_x,lookAt_y,lookAt_z,0,1,0);
	}
	
	
	private void drawObjects(){
		glColor4f(0.3f,0.3f,0.3f,1);
		glBegin(GL_QUADS);
		glVertex3f(-35,2,-35);
		glVertex3f(-35,2, 15);
		glVertex3f( 15,2, 15);
		glVertex3f( 15,2,-35);
		glEnd();
		
		glColor4f(0.9f,0.9f,0.9f,1);
		
		startTranslate(0,4,-16);		
		drawQuad(4);
		endTranslate();
		
		startTranslate(0,4,-5);
		drawQuad(4);
		endTranslate();
	}
	
	
	private void drawQuad(float radius){
		glPushMatrix();
		glScalef(radius,radius,radius);
		GL11.glBegin(GL11.GL_QUADS);    
        GL11.glColor3f(1.0f,1.0f,0.0f);           
        GL11.glVertex3f( 1.0f, 1.0f,-1.0f);        
        GL11.glVertex3f(-1.0f, 1.0f,-1.0f);        
        GL11.glVertex3f(-1.0f, 1.0f, 1.0f);
        GL11.glVertex3f( 1.0f, 1.0f, 1.0f);  
        GL11.glColor3f(1.0f,0.5f,0.0f);            
        GL11.glVertex3f( 1.0f,-1.0f, 1.0f);
        GL11.glVertex3f(-1.0f,-1.0f, 1.0f);
        GL11.glVertex3f(-1.0f,-1.0f,-1.0f);
        GL11.glVertex3f( 1.0f,-1.0f,-1.0f);
        GL11.glColor3f(1.0f,0.0f,0.0f);
        GL11.glVertex3f( 1.0f, 1.0f, 1.0f);
        GL11.glVertex3f(-1.0f, 1.0f, 1.0f);
        GL11.glVertex3f(-1.0f,-1.0f, 1.0f);
        GL11.glVertex3f( 1.0f,-1.0f, 1.0f);
        GL11.glColor3f(1.0f,1.0f,0.0f);
        GL11.glVertex3f( 1.0f,-1.0f,-1.0f);
        GL11.glVertex3f(-1.0f,-1.0f,-1.0f);
        GL11.glVertex3f(-1.0f, 1.0f,-1.0f);
        GL11.glVertex3f( 1.0f, 1.0f,-1.0f);
        GL11.glColor3f(0.0f,0.0f,1.0f);
        GL11.glVertex3f(-1.0f, 1.0f, 1.0f);
        GL11.glVertex3f(-1.0f, 1.0f,-1.0f);
        GL11.glVertex3f(-1.0f,-1.0f,-1.0f);
        GL11.glVertex3f(-1.0f,-1.0f, 1.0f);
        GL11.glColor3f(1.0f,0.0f,1.0f);
        GL11.glVertex3f( 1.0f, 1.0f,-1.0f);
        GL11.glVertex3f( 1.0f, 1.0f, 1.0f);
        GL11.glVertex3f( 1.0f,-1.0f, 1.0f);
        GL11.glVertex3f( 1.0f,-1.0f,-1.0f);
    GL11.glEnd();    
    glPopMatrix();
	}
	
	private void startTranslate(float x,float y,float z)
	{
		glPushMatrix();
		glTranslatef(x,y,z);
		
		glMatrixMode(GL_TEXTURE);
		GL13.glActiveTexture(GL13.GL_TEXTURE7);
		glPushMatrix();
		glTranslatef(x,y,z);
	}

	private void endTranslate(){
		glPopMatrix();
		glMatrixMode(GL_MODELVIEW);
		glPopMatrix();
	}

But for some reason my shaded textureID texture is coming up black.

I assume the problem is either in constructor, the "drawShadow" method, or the "setTextureMatrix" method.

Hopefully someone will be able to fix this?

Thanks in advanced