X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=shaderlib%2Fcooktorrance.glsl;h=25289ed57bc916af3eb41a4f9893d99289399618;hb=afffed5bf161b5972a02f055225701118ed5a4e7;hp=c866058de4dbd0c6dd06fd7b28ad72c25f5b7c44;hpb=6dcf74922f46b086ad394c19fd6ce083a635b290;p=libs%2Fgl.git

diff --git a/shaderlib/cooktorrance.glsl b/shaderlib/cooktorrance.glsl
index c866058d..25289ed5 100644
--- a/shaderlib/cooktorrance.glsl
+++ b/shaderlib/cooktorrance.glsl
@@ -1,23 +1,45 @@
 import msp_interface;
 import common;
+import environment;
 import shadow;
 
+struct PbrMaterialParameters
+{
+	vec4 base_color;
+	vec4 tint;
+	vec4 emission;
+	float metalness;
+	float roughness;
+};
+
+layout(set=1) uniform PbrMaterial
+{
+	PbrMaterialParameters pbr_material;
+	AlphaCutoffParams alpha_cutoff;
+};
+
+layout(set=1) uniform sampler2D base_color_map;
+layout(set=1) uniform sampler2D metalness_map;
+layout(set=1) uniform sampler2D roughness_map;
+layout(set=1) uniform sampler2D occlusion_map;
+layout(set=1) uniform sampler2D emission_map;
+layout(set=1) uniform sampler2D fresnel_lookup;
+
 layout(constant_id=auto) const bool use_base_color_map = false;
 layout(constant_id=auto) const bool use_metalness_map = false;
 layout(constant_id=auto) const bool use_roughness_map = false;
 layout(constant_id=auto) const bool use_occlusion_map = false;
 layout(constant_id=auto) const bool use_emission = false;
 layout(constant_id=auto) const bool use_emission_map = false;
-
-const float PI = 3.1415926535;
+layout(constant_id=auto) const bool use_image_based_lighting = false;
 
 #pragma MSP stage(fragment)
 virtual vec4 get_base_color()
 {
 	if(use_base_color_map)
-		return texture(base_color_map, texcoord.xy);
+		return texture(base_color_map, texcoord.xy)*pbr_material.tint;
 	else
-		return pbr_material.base_color;
+		return pbr_material.base_color*pbr_material.tint;
 }
 
 virtual float get_metalness_value()
@@ -55,7 +77,8 @@ virtual vec3 get_emission_color()
 /* Computes the diffuse reflection of the macrosurface */
 vec3 lambert_diffuse(vec3 base_color)
 {
-	// Scale by pi to get a result per steradian, suitable for integration
+	/* Scale by pi (cosine-weighted area of a hemisphere) because the light
+	scatters in every direction */
 	return base_color/PI;
 }
 
@@ -67,7 +90,8 @@ float normal_distribution_ggxtr(vec3 normal, vec3 halfway, float roughness)
 	float rough_q = roughness * roughness;
 	rough_q *= rough_q;
 	float denom = n_dot_h*n_dot_h*(rough_q-1)+1;
-	// Scale by pi to get a result per steradian, suitable for integration
+	/* Scale by pi to normalize the total area of the microfacets as projected
+	to the macrosurface */
 	return rough_q/(PI*denom*denom);
 }
 
@@ -94,11 +118,11 @@ vec3 fresnel_schlick(vec3 halfway, vec3 look, vec3 base_color, float metalness)
 {
 	// 0.04 is a decent approximation for dielectric base reflectivity
 	vec3 f0 = mix(vec3(0.04), base_color, metalness);
-	return mix(f0, vec3(1.0), pow(1.0-dot(halfway, look), 5.0));
+	return mix(f0, vec3(1.0), pow(max(1.0-dot(halfway, look), 0.0), 5.0));
 }
 
 /* Computes the full contribution of a single light */
-vec3 cooktorrance_one_light_direct(vec3 normal, vec3 look, vec3 light, vec3 light_color, vec3 base_color, float metalness, float roughness)
+vec3 cooktorrance_one_light_direct(vec3 normal, vec3 look, vec3 light, vec3 base_color, float metalness, float roughness)
 {
 	vec3 halfway = normalize(light-look);
 	float ndist = normal_distribution_ggxtr(normal, halfway, roughness);
@@ -107,22 +131,41 @@ vec3 cooktorrance_one_light_direct(vec3 normal, vec3 look, vec3 light, vec3 ligh
 	vec3 k_spec = fresnel_schlick(halfway, light, base_color, metalness);
 	vec3 k_diff = (1.0-k_spec)*(1.0-metalness);
 
-	float denom = max(4.0*max(dot(normal, -look), 0.0)*max(dot(normal, light), 0.0), 0.001);
-	return max(dot(normal, light), 0.0)*light_color*(k_diff*lambert_diffuse(base_color)+k_spec*ndist*geom/denom);
+	float spec_denom = max(4.0*max(dot(normal, -look), 0.0)*max(dot(normal, light), 0.0), 0.001);
+	return max(dot(normal, light), 0.0)*(k_diff*lambert_diffuse(base_color)+k_spec*ndist*geom/spec_denom);
 }
 
-vec3 cooktorrance_lighting(vec3 normal, vec3 look, vec3 base_color, float metalness, float roughness)
+vec3 cooktorrance_environment(vec3 normal, vec3 look, vec3 base_color, float metalness, float roughness)
 {
-	vec3 light;
-	if(use_normal_map)
-		light = normalize(tbn_light_dir);
-	else
-		light = normalize(eye_light_dir);
+	vec3 f0 = mix(vec3(0.04), base_color, metalness);
+	vec2 scale_bias = texture(fresnel_lookup, vec2(roughness, max(dot(normal, -look), 0.0))).rg;
+	vec3 k_spec = f0*scale_bias.x+scale_bias.y;
+	vec3 k_diff = (1.0-k_spec)*(1.0-metalness);
 
-	float shadow = get_shadow_factor(0);
-	vec3 color = cooktorrance_one_light_direct(normal, look, light, light_sources[0].diffuse.rgb, base_color, metalness, roughness)*shadow;
+	if(use_image_based_lighting)
+	{
+		vec3 irradiance = get_irradiance_sample(normal);
+		vec3 reflection = get_environment_sample(reflect(look, normal), roughness).rgb;
+
+		return k_diff*irradiance*base_color+k_spec*reflection;
+	}
+	else
+		return (k_diff*base_color+k_spec)*ambient_color.rgb;
+}
 
-	color *= get_occlusion_value();
+vec3 cooktorrance_lighting(vec3 normal, vec3 look, vec3 base_color, float metalness, float roughness)
+{
+	vec3 color = vec3(0.0);
+	for(int i=0; i<max_lights; ++i)
+		if(light_sources[i].type!=0)
+		{
+			IncomingLight incoming = get_incoming_light(i, world_vertex.xyz);
+			float shadow = get_shadow_factor(i, world_vertex);
+			color += cooktorrance_one_light_direct(normal, look, incoming.direction, base_color, metalness, roughness)*incoming.color*shadow;
+		}
+
+	float occlusion = get_occlusion_value();
+	color += cooktorrance_environment(normal, look, base_color, metalness, roughness)*occlusion;
 
 	if(use_emission)
 		color += get_emission_color();
@@ -132,24 +175,16 @@ vec3 cooktorrance_lighting(vec3 normal, vec3 look, vec3 base_color, float metaln
 
 void main()
 {
-	vec3 normal;
-	vec3 look;
-	if(use_normal_map)
-	{
-		normal = get_fragment_normal();
-		look = normalize(tbn_look_dir);
-	}
-	else
-	{
-		normal = normalize(eye_normal);
-		look = normalize(eye_look_dir);
-	}
-
 	vec4 base_color = get_base_color();
+	float alpha = apply_alpha_cutoff(base_color.a, alpha_cutoff);
+
+	vec3 normal = get_fragment_normal();
+	vec3 look = normalize(world_look_dir);
+
 	float metalness = get_metalness_value();
 	float roughness = get_roughness_value();
 
 	vec3 lit_color = cooktorrance_lighting(normal, look, base_color.rgb, metalness, roughness);
 
-	frag_color = vec4(lit_color, base_color.a);
+	frag_color = vec4(lit_color, alpha);
 }