engine/assets/shaders/mesh.glsl

240 lines
7.2 KiB
GLSL

#extension GL_ARB_bindless_texture : enable
// Keep in sync with cpu
#define MAX_POINT_LIGHTS 8
#define PI 3.1415926535897932384626433832795
// Types
struct Light {
vec4 vPos;
vec4 color;
};
// UBOs
layout(std140, binding = 0) uniform Matrices {
mat4 projection;
mat4 view;
};
// TODO: rename
layout(std140, binding = 1) uniform Lights {
Light lights[MAX_POINT_LIGHTS];
uint lights_count;
};
// Uniforms
layout(location = 1) uniform mat4 model;
layout(location = 2) uniform vec3 color;
layout(location = 3, bindless_sampler) uniform sampler2D albedo_map;
layout(location = 4) uniform vec2 albedo_map_uv_scale = vec2(1);
layout(location = 5, bindless_sampler) uniform sampler2D normal_map;
layout(location = 6) uniform vec2 normal_map_uv_scale = vec2(1);
layout(location = 7) uniform float metallic;
layout(location = 8, bindless_sampler) uniform sampler2D metallic_map;
layout(location = 9) uniform vec2 metallic_map_uv_scale = vec2(1);
layout(location = 10) uniform float roughness;
layout(location = 11, bindless_sampler) uniform sampler2D roughness_map;
layout(location = 12) uniform vec2 roughness_map_uv_scale = vec2(1);
layout(location = 13) uniform vec3 emission;
layout(location = 14, bindless_sampler) uniform sampler2D emission_map;
layout(location = 15) uniform vec2 emission_map_uv_scale = vec2(1);
layout(location = 16, bindless_sampler) uniform sampler2DArrayShadow shadow_maps;
layout(location = 17) uniform mat4 shadow_map_vp;
// Input, output blocks
VERTEX_EXPORT VertexData {
vec3 vPos;
vec2 uv;
mat3 vTBN;
vec3 wPos;
} VertexOut;
float random(vec4 seed4) {
float dot_product = dot(seed4, vec4(12.9898,78.233,45.164,94.673));
return fract(sin(dot_product) * 43758.5453);
}
#if VERTEX_SHADER
layout(location = 0) in vec3 aPos;
layout(location = 1) in vec3 aNormal;
layout(location = 2) in vec2 aUV;
layout(location = 3) in vec3 aTangent;
void main() {
vec4 vPos = view * model * vec4(aPos.xyz, 1.0);
gl_Position = projection * vPos;
VertexOut.vPos = vPos.xyz / vPos.w; // I don't think this is needed, but leaving just in case
VertexOut.uv = aUV;
vec3 aBitangent = cross(aTangent, aNormal);
vec3 T = normalize(vec3(view * model * vec4(aTangent, 0.0)));
vec3 B = normalize(vec3(view * model * vec4(aBitangent, 0.0)));
vec3 N = normalize(vec3(view * model * vec4(aNormal, 0.0)));
VertexOut.vTBN = mat3(T, B, N);
vec4 wPos = model * vec4(aPos.xyz, 1.0);
VertexOut.wPos = wPos.xyz / wPos.w;
}
#endif // VERTEX_SHADER
#if FRAGMENT_SHADER
out vec4 FragColor;
struct Material {
vec3 albedo;
bool metallic;
float roughness;
vec3 emission;
};
Material evalMaterial() {
Material result;
result.albedo = textureSize(albedo_map, 0) == ivec2(0) ? pow(color, vec3(2.2)) : texture(albedo_map, VertexOut.uv * albedo_map_uv_scale).rgb;
float fMetallic = textureSize(metallic_map, 0) == ivec2(0) ? metallic : texture(metallic_map, VertexOut.uv * metallic_map_uv_scale).b;
result.metallic = fMetallic > 0.1;
result.roughness = max(0.01, textureSize(roughness_map, 0) == ivec2(0) ? roughness : texture(roughness_map, VertexOut.uv * roughness_map_uv_scale).g);
result.emission = textureSize(emission_map, 0) == ivec2(0) ? emission : texture(emission_map, VertexOut.uv * emission_map_uv_scale).rgb;
return result;
}
vec3 schlickFresnel(Material mat, float LDotH) {
vec3 f0 = vec3(0.04); // dielectric
if (mat.metallic) {
f0 = mat.albedo;
}
return f0 + (1 - f0) * pow(1.0 - LDotH, 5);
}
float geomSmith(Material mat, float DotVal) {
float k = (mat.roughness + 1.0) * (mat.roughness + 1.0) / 8.0;
float denom = DotVal * (1 - k) + k;
return 1.0 / denom;
}
float ggxDistribution(Material mat, float NDotH) {
float alpha2 = mat.roughness * mat.roughness * mat.roughness * mat.roughness;
float d = (NDotH * NDotH) * (alpha2 - 1) + 1;
return alpha2 / (PI * d * d);
}
float lightAttenuation(float point, float dist, float radius) {
float d = max(dist - radius, 0) * point;
float denom = d/radius + 1;
float att = 1 / (denom * denom);
// TODO: cutoff
att = max(att, 0);
return att;
}
vec2 poissonDisk[4] = vec2[](
vec2( -0.94201624, -0.39906216 ),
vec2( 0.94558609, -0.76890725 ),
vec2( -0.094184101, -0.92938870 ),
vec2( 0.34495938, 0.29387760 )
);
vec3 microfacetModel(Material mat, Light light, vec3 P, vec3 N) {
vec3 diffuseBrdf = vec3(0); // metallic
if (!mat.metallic) {
diffuseBrdf = mat.albedo;
}
// 0 - means directional, 1 - means point light
float point = light.vPos.w;
vec3 lightI = light.color.rgb;
float lightRadius = light.color.a;
vec3 L = mix(-light.vPos.xyz, light.vPos.xyz - P, light.vPos.w);
float dist = length(L);
L /= dist;
// TODO: I think this is uniform control flow
// so makes sense to use `if` there for directional/point
// and don't calculate attenuation for directional at all
float att = lightAttenuation(
point,
dist,
lightRadius
);
lightI *= att;
vec3 V = normalize(-P);
vec3 H = normalize(V + L);
float NDotH = dot(N, H);
float LDotH = dot(L, H);
float NDotL = max(dot(N, L), 0);
float NDotV = dot(N, V);
float shadow_mult = 1;
//// TODO: Shadows for directional light only for now
if (point == 0) {
vec4 shadow_pos = shadow_map_vp * vec4(VertexOut.wPos, 1.0);
shadow_pos /= shadow_pos.w;
shadow_pos.xyz = shadow_pos.xyz * 0.5 + 0.5; // [-1, 1] to [0, 1]
float bias = 0.005 * tan(acos(NDotL));
shadow_pos.z -= bias;
vec4 texcoord;
texcoord.xyw = shadow_pos.xyz; // sampler2DArrayShadow strange texcoord mapping
texcoord.z = 0; // First shadow map
float sum = 0;
vec2 tex_scale = 1.0 / vec2(textureSize(shadow_maps, 0));
for (float y = -1.5; y <= 1.5; y += 1) {
for (float x = -1.5; x <= 1.5; x += 1) {
sum += texture(shadow_maps, vec4(texcoord.xy + vec2(x, y) * tex_scale, texcoord.zw));
}
}
shadow_mult = sum / 16.0;
// for (int i=0; i<4; i++){
// int index = int(16.0 * random(vec4(VertexOut.wPos.xyz * 1000.0, i))) % 4;
// float depth_test = texture(shadow_maps, vec4(texcoord.xy + poissonDisk[index]/700.0, texcoord.zw));
// shadow_mult -= 0.25 * (1 - depth_test);
// }
//shadow_mult = texture(shadow_maps, texcoord);
}
vec3 specBrdf = 0.25 * ggxDistribution(mat, NDotH) * schlickFresnel(mat, LDotH) * geomSmith(mat, NDotL) * geomSmith(mat, NDotV);
return (diffuseBrdf + PI * specBrdf) * lightI * NDotL * shadow_mult;
}
void main() {
Material material = evalMaterial();
vec3 N = textureSize(normal_map, 0) == ivec2(0) ? vec3(0.5) : vec3(texture(normal_map, VertexOut.uv * normal_map_uv_scale).xy, 0);
N = N * 2.0 - 1.0;
N.z = sqrt(clamp(1 - N.x * N.x - N.y * N.y, 0, 1));
N = normalize(N);
N = normalize(VertexOut.vTBN * N);
vec3 finalColor = vec3(0);
for (int i = 0; i < lights_count; i++) {
finalColor += microfacetModel(material, lights[i], VertexOut.vPos, N);
}
FragColor = vec4(finalColor, 1.0f);
float gamma = 2.2;
FragColor.rgb = pow(FragColor.rgb, vec3(1.0/gamma));
}
#endif // FRAGMNET_SHADER