118 lines
2.9 KiB
GLSL
118 lines
2.9 KiB
GLSL
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#version 450 core
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layout(location=0) in vec3 FragmentWorldPos;
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layout(location=1) in vec3 FragmentWorldNormal;
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layout(location=0) out vec4 FragColor;
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layout(binding=10) uniform WorldMatrix // hgl/math/Math.h
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{
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mat4 ortho;
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mat4 projection;
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mat4 inverse_projection;
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mat4 modelview;
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mat4 inverse_modelview;
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mat4 mvp;
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mat4 inverse_mvp;
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vec4 camera_pos;
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vec2 canvas_resolution;
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vec2 viewport_resolution;
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}fs_world;
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layout(binding=1) uniform PBRMaterial
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{
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vec4 color;
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float metallic;
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float roughness;
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} pbr_material;
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layout(binding=2) uniform Sun
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{
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vec3 direction;
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}sun;
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const float PI = 3.14159265359;
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// Normal Distribution function --------------------------------------
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float D_GGX(float dotNH, float roughness)
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{
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float alpha = roughness * roughness;
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float alpha2 = alpha * alpha;
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float denom = dotNH * dotNH * (alpha2 - 1.0) + 1.0;
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return (alpha2)/(PI * denom*denom);
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}
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// Geometric Shadowing function --------------------------------------
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float G_SchlicksmithGGX(float dotNL, float dotNV, float roughness)
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{
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float r = (roughness + 1.0);
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float k = (r*r) / 8.0;
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float GL = dotNL / (dotNL * (1.0 - k) + k);
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float GV = dotNV / (dotNV * (1.0 - k) + k);
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return GL * GV;
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}
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// Fresnel function ----------------------------------------------------
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vec3 F_Schlick(float cosTheta, float metallic)
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{
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vec3 F0 = mix(vec3(0.04), pbr_material.color.rgb, metallic); // * material.specular
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vec3 F = F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
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return F;
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}
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// Specular BRDF composition --------------------------------------------
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vec3 BRDF(vec3 L, vec3 V, vec3 N, float metallic, float roughness)
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{
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// Precalculate vectors and dot products
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vec3 H = normalize (V + L);
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float dotNV = clamp(dot(N, V), 0.0, 1.0);
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float dotNL = clamp(dot(N, L), 0.0, 1.0);
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float dotLH = clamp(dot(L, H), 0.0, 1.0);
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float dotNH = clamp(dot(N, H), 0.0, 1.0);
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// Light color fixed
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vec3 lightColor = vec3(1.0);
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vec3 color = vec3(0.0);
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if (dotNL > 0.0)
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{
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float rroughness = max(0.05, roughness);
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// D = Normal distribution (Distribution of the microfacets)
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float D = D_GGX(dotNH, roughness);
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// G = Geometric shadowing term (Microfacets shadowing)
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float G = G_SchlicksmithGGX(dotNL, dotNV, roughness);
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// F = Fresnel factor (Reflectance depending on angle of incidence)
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vec3 F = F_Schlick(dotNV, metallic);
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vec3 spec = D * F * G / (4.0 * dotNL * dotNV);
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color += spec * dotNL * lightColor;
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}
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return color;
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}
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// ----------------------------------------------------------------------------
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void main()
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{
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vec3 N = normalize(FragmentWorldNormal);
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vec3 V = normalize(fs_world.camera_pos.xyz - FragmentWorldPos);
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// Specular contribution
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vec3 Lo = BRDF(sun.direction, V, N, pbr_material.metallic, pbr_material.roughness);
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// Combine with ambient
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vec3 color = (pbr_material.color.rgb * 0.02)+Lo;
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// Gamma correct
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color = pow(color, vec3(0.4545));
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FragColor = vec4(color, 1.0);
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}
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