116 lines
3.2 KiB
C
116 lines
3.2 KiB
C
// -*- mode: C; -*-
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// Licence: GPL v2
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// Author: Frederic Bouvier.
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// Adapted from the paper by F. Policarpo et al. : Real-time Relief Mapping on Arbitrary Polygonal Surfaces
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#version 120
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varying vec4 rawpos;
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varying vec4 ecPosition;
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varying vec3 VNormal;
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varying vec3 VTangent;
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varying vec3 VBinormal;
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varying vec3 Normal;
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varying vec4 constantColor;
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uniform sampler2D BaseTex;
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uniform sampler2D NormalTex;
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uniform float depth_factor;
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uniform float tile_size;
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uniform vec3 night_color;
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const float zFar = 120000.0;
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const float zNear = 100.0;
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float ray_intersect(sampler2D reliefMap, vec2 dp, vec2 ds)
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{
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const int linear_search_steps = 20;
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float size = 1.0 / float(linear_search_steps);
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float depth = 0.0;
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float best_depth = 1.0;
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for(int i = 0; i < linear_search_steps - 1; ++i)
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{
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depth += size;
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float t = texture2D(reliefMap, dp + ds * depth).a;
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if(best_depth > 0.996)
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if(depth >= t)
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best_depth = depth;
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}
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depth = best_depth;
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const int binary_search_steps = 5;
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for(int i = 0; i < binary_search_steps; ++i)
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{
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size *= 0.5;
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float t = texture2D(reliefMap, dp + ds * depth).a;
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if(depth >= t)
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{
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best_depth = depth;
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depth -= 2.0 * size;
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}
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depth += size;
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}
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return(best_depth);
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}
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void main (void)
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{
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vec3 ecPos3 = ecPosition.xyz / ecPosition.w;
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vec3 V = normalize(ecPos3);
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vec3 s = vec3(dot(V, VTangent), dot(V, VBinormal), dot(VNormal, -V));
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vec2 ds = s.xy * depth_factor / s.z;
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vec2 dp = gl_TexCoord[0].st - ds;
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float d = ray_intersect(NormalTex, dp, ds);
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vec2 uv = dp + ds * d;
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vec3 N = texture2D(NormalTex, uv).xyz * 2.0 - 1.0;
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float emis = N.z;
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N.z = sqrt(1.0 - min(1.0,dot(N.xy, N.xy)));
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N = normalize(N.x * VTangent + N.y * VBinormal + N.z * VNormal);
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vec3 l = gl_LightSource[0].position.xyz;
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vec3 diffuse = gl_Color.rgb * max(0.0, dot(N, l));
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// Shadow
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dp += ds * d;
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vec3 sl = normalize( vec3( dot( l, VTangent ), dot( l, VBinormal ), dot( -l, VNormal ) ) );
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ds = sl.xy * depth_factor / sl.z;
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dp -= ds * d;
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float dl = ray_intersect(NormalTex, dp, ds);
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float shadow_factor = 1.0;
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if ( dl < d - 0.05 )
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shadow_factor = dot( constantColor.xyz, vec3( 1.0, 1.0, 1.0 ) ) * 0.25;
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// end shadow
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vec4 ambient_light = constantColor + gl_LightSource[0].diffuse * vec4(diffuse, 1.0);
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float reflectance = ambient_light.r * 0.3 + ambient_light.g * 0.59 + ambient_light.b * 0.11;
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if ( shadow_factor < 1.0 )
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ambient_light = constantColor + gl_LightSource[0].diffuse * shadow_factor * vec4(diffuse, 1.0);
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float emission_factor = (1.0 - smoothstep(0.15, 0.25, reflectance)) * emis;
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vec4 tc = texture2D(BaseTex, uv);
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emission_factor *= 0.5*pow(tc.r+0.8*tc.g+0.2*tc.b, 2) -0.2;
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ambient_light += (emission_factor * vec4(night_color, 0.0));
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vec4 finalColor = texture2D(BaseTex, uv) * ambient_light;
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float fogFactor;
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float fogCoord = ecPos3.z / (1.0 + smoothstep(0.3, 0.7, emission_factor));
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const float LOG2 = 1.442695;
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fogFactor = exp2(-gl_Fog.density * gl_Fog.density * fogCoord * fogCoord * LOG2);
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fogFactor = clamp(fogFactor, 0.0, 1.0);
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if (gl_Fog.density == 1.0)
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fogFactor=1.0;
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vec4 p = vec4( ecPos3 + tile_size * V * (d-1.0) * depth_factor / s.z, 1.0 );
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vec4 iproj = gl_ProjectionMatrix * p;
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iproj /= iproj.w;
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gl_FragColor = mix(gl_Fog.color ,finalColor, fogFactor);
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gl_FragDepth = (iproj.z+1.0)/2.0;
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}
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