Loads of shader and lighting stuff

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@39 84d2e878-0bd5-11dd-ad15-13eda11d74c5

2 files changed, 68 insertions, 46 deletions

diff --git a/data/shaders/lighting.frag b/data/shaders/lighting.frag
index ee1df5b..77102e9 100644
--- a/data/shaders/lighting.frag
+++ b/data/shaders/lighting.frag
@@ -9,43 +9,56 @@
  *
  */
 
-varying vec4 col_ambi;
-varying vec4 col_diff;
-varying vec4 col_spec;
-varying vec4 col_emit;
-varying float shininess;
-
 varying vec3 normal;
-varying vec3 halfvc;
+
+varying vec3 light0vc;
+varying vec3 light1vc;
+varying vec3 light2vc;
+varying vec3 light2hvc;
 
 uniform sampler2D texture;
+uniform int fill_light_enabled;
+
+varying vec3 col_ambi_diff;
+varying vec3 col_emit;
 
 void main() {
 	
-	vec4 ambi;
-	vec4 diff;
-	vec4 spec;
-	vec3 light;
-	vec3 norml;
-	
-	/* Ambient contribution */
-	ambi = col_ambi * gl_LightModel.ambient;
-	ambi += col_ambi * gl_LightSource[0].ambient;
-	ambi = vec4(0.0, 0.0, 0.0, 1.0);
-	
-	/* Diffuse contribution */
-	light = vec3(normalize(gl_LightSource[0].position));
-	norml = normalize(normal);
-	diff = col_diff * clamp(dot(light, normal), 0.0, 1.0);
-	
-	/* Specular contribution */
-	spec = col_spec * clamp(pow(dot( vec3(normal), halfvc ), shininess), 0.0, 1.0);
-	spec = vec4(0.0, 0.0, 0.0, 1.0);
-	
-	gl_FragColor = vec4(min(col_emit.r + ambi.r + diff.r + spec.r, 1.0),
-			    min(col_emit.g + ambi.g + diff.g + spec.g, 1.0),
-			    min(col_emit.b + ambi.b + diff.b + spec.b, 1.0),
-			    min(col_emit.a + ambi.a + diff.a + spec.a, 1.0));
+	vec3 ambi;
+	vec3 emit;
+	vec3 diff = vec3(0.0, 0.0, 0.0);
+	vec3 spec = vec3(0.0, 0.0, 0.0);
+	
+	vec3 norm = normalize(normal);
+	
+	/* Ambient */
+	ambi = col_ambi_diff * gl_LightModel.ambient.rgb;
+	
+	/* Emission */
+	emit = col_emit;
+	
+	/* Spotlight (light 0) - diffuse only, positional, spotlight */
+	float falloff = 1 - length(light0vc) * gl_LightSource[0].linearAttenuation;
+	float spot = max(dot(normalize(-light0vc), gl_LightSource[0].spotDirection), 0.0);
+	spot = pow(spot, gl_LightSource[0].spotExponent);
+	diff += col_ambi_diff * gl_LightSource[0].diffuse.rgb * spot * falloff * max(dot(normalize(light0vc).xyz, norm), 0.0);
+	
+	/* Background glow (light 1) - diffuse only, directional */
+	diff += col_ambi_diff * gl_LightSource[1].diffuse.rgb * max(dot(vec3(light1vc), norm), 0.0);
+	
+	/* Fill-in light (light 2) - this is the only one which has a specular component */
+	if ( fill_light_enabled == 1 ) {
+		/* Diffuse */
+		diff += col_ambi_diff * gl_LightSource[2].diffuse.rgb * max(dot(vec3(light1vc), norm), 0.0);
+		/* Specular */
+		float ndothv = max(dot(norm, normalize(light2hvc)), 0.0);
+		spec = vec3(1.0, 1.0, 1.0) * gl_LightSource[2].specular.rgb * pow(ndothv, 80.0);
+	}
+	
+	gl_FragColor = vec4(min(emit.r + ambi.r + diff.r + spec.r, 1.0),
+			    min(emit.g + ambi.g + diff.g + spec.g, 1.0),
+			    min(emit.b + ambi.b + diff.b + spec.b, 1.0),
+			    1.0);
 	
 	gl_FragColor *= texture2D(texture, gl_TexCoord[0].st);
 	
diff --git a/data/shaders/lighting.vert b/data/shaders/lighting.vert
index eaa51c2..1817e9f 100644
--- a/data/shaders/lighting.vert
+++ b/data/shaders/lighting.vert
@@ -9,27 +9,36 @@
  *
  */
 
-varying vec4 col_ambi;
-varying vec4 col_diff;
-varying vec4 col_spec;
-varying vec4 col_emit;
-varying float shininess;
-
 varying vec3 normal;
-varying vec3 halfvc;
+
+varying vec3 light0vc;
+varying vec3 light1vc;
+varying vec3 light2vc;
+varying vec3 light2hvc;
+
+uniform int fill_light_enabled;
+
+varying vec3 col_ambi_diff;
+varying vec3 col_emit;
 
 void main() {
 	
-	/* Directions */
-	normal = normalize(gl_NormalMatrix * gl_Normal);
-	halfvc = vec3(gl_LightSource[0].halfVector);
+	/* Spotlight - positional light */
+	vec4 vert = gl_ModelViewMatrix * gl_Vertex;
+	light0vc = gl_LightSource[0].position.xyz - vert.xyz;
+	
+	/* Diffuse "background glow" - this can be normalised only once, here, since 'position'
+	 * is really 'direction' and is the same for all vertices. */
+	light1vc = normalize(vec3(gl_LightSource[1].position));
+	
+	/* Fill-in light */
+	light2vc = normalize(vec3(gl_LightSource[2].position));
+	light2hvc = normalize(gl_LightSource[2].halfVector.xyz);
 	
 	/* Material properties */
-	col_ambi = gl_FrontMaterial.ambient;
-	col_diff = gl_FrontMaterial.diffuse;
-	col_spec = gl_FrontMaterial.specular;
-	col_emit = gl_FrontMaterial.emission;
-	shininess = gl_FrontMaterial.shininess;
+	normal = gl_NormalMatrix * gl_Normal;
+	col_ambi_diff = gl_Color.rgb;
+	col_emit = gl_FrontMaterial.emission.rgb;
 	
 	/* Coordinates */
 	gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;