Implementacija shadera u GLSL-u

Primjer 1

Vertex shader:

		varying vec3 LightDir;
		varying vec3 EyeDir;
		varying vec3 Normal;

		uniform vec3 LightPosition;
		uniform float Scale;

		void main(void) 
		{
			vec4 pos = gl_ModelViewMatrix * gl_Vertex;
			gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
			vec3 eyeDir = vec3(pos);
			gl_TexCoord[0] = gl_MultiTexCoord0;

			vec3 n = normalize(gl_NormalMatrix * gl_Normal);
			vec3 t = normalize(cross(vec3(1.141, 2.78, 3.14), n));
			vec3 b = cross(n, t);

			vec3 v;
			v.x = dot(LightPosition, t);
			v.y = dot(LightPosition, b);
			v.z = dot(LightPosition, n);
			LightDir = normalize(v);

			v.x = dot(eyeDir, t);
			v.y = dot(eyeDir, b);
			v.z = dot(eyeDir, n);
			EyeDir = normalize(v);
		}

Fragment shader:

		
		varying vec3 LightDir;
		varying vec3 EyeDir;
		varying vec3 Normal;

		const vec3 color = vec3(0.9, 0.8, 0.60);

		const float Density = 16.0;
		const float Size = 0.15;
		const float SpecularFactor = 0.5;

		void main (void)
		{
			vec3 litColor;

			vec2 c = Density * vec2(gl_TexCoord[0]);
			vec2 p = fract(c) - vec2(0.5);

			float d;

			d = p.x * p.x + p.y * p.y;
			if (d >= Size)
				p = vec2(0.0);

			vec3 normDelta = vec3(-p.x, -p.y, 1.0);
			  
			litColor = color * max(0.0, dot(normDelta, LightDir));
			  
			float t = 2.0 * dot(LightDir, normDelta);
			vec3 reflectDir = t * normDelta;
			reflectDir = LightDir - reflectDir;
			
			float spec = max(dot(EyeDir, reflectDir), 0.0);
			spec = spec * spec;
			spec = spec * spec;
			spec *= SpecularFactor;

			litColor = min(litColor + spec, vec3(1.0));

			gl_FragColor = vec4(litColor, 1.0);
		}

Primjer2

Vertex shader:

		attribute vec3 tangent;
		attribute vec3 binormal;
		varying vec3 eyeVec;
		void main() 
		{ 
			 gl_TexCoord[0] = gl_MultiTexCoord0; 
		 
			 mat3 TBN_Matrix;// = mat3(tangent, binormal, gl_Normal);  
			 TBN_Matrix[0] =  gl_NormalMatrix * tangent; 
			 TBN_Matrix[1] =  gl_NormalMatrix * binormal; 
			 TBN_Matrix[2] =  gl_NormalMatrix * gl_Normal; 
			 vec4 Vertex_ModelView = gl_ModelViewMatrix * gl_Vertex; 
			 eyeVec = vec3(-Vertex_ModelView) * TBN_Matrix ;      
			 // Vertex transformation 
			 gl_Position = ftransform(); 
		}

Fragment shader:

		uniform sampler2D basetex;
		uniform sampler2D bumptex;
		varying vec3 eyeVec;

		void main()
		{
			vec2 texUV, srcUV = gl_TexCoord[0].xy;
			float height = texture2D(bumptex, srcUV).r;
			float v = height * 0.04 - 0.02;
			vec3 eye = normalize(eyeVec);
			texUV = srcUV + (eye.xy * v);        
				
			vec3 rgb = texture2D(basetex, texUV).rgb;

			// output final color
		   gl_FragColor = vec4(vec3(rgb), 1.0);
		   // gl_FragColor = vec4(vec3(rgb)*height, 1.0);
		  
		}

Ljubo Barać | Računalna grafika