Files
Nuake/Data/Shaders/deferred.shader
2025-01-31 18:04:43 -05:00

410 lines
12 KiB
GLSL

#shader vertex
#version 440 core
layout(location = 0) in vec3 VertexPosition;
layout(location = 1) in vec2 UVPosition;
out flat vec2 UV;
out mat4 InvProjection;
out mat4 InvView;
uniform mat4 u_Projection;
uniform mat4 u_View;
void main()
{
UV = UVPosition;
InvProjection = inverse(u_Projection);
InvView = inverse(u_View);
gl_Position = vec4(VertexPosition, 1.0f);
}
#shader fragment
#version 440 core
out vec4 FragColor;
in vec2 UV;
in mat4 InvProjection;
in mat4 InvView;
// Camera
uniform vec3 u_EyePosition;
// GBuffer
uniform sampler2D m_Depth;
uniform sampler2D m_Albedo;
uniform sampler2D m_Material;
uniform sampler2D m_Normal;
uniform sampler2D m_SSAO;
uniform sampler2D m_Emissive;
uniform sampler2D m_UVOffset;
// Lights
const int MaxLight = 42;
uniform int LightCount = 0;
struct Light {
vec3 Color;
vec3 Position;
int Type; // 0 = Point, 1 = Directional, 2 = Spot
vec3 Direction;
float OuterAngle;
float InnerAngle;
int CastShadow; // For SpotLight for now
int ShadowMapID;
mat4 Transform;
};
struct DirectionalLight
{
vec3 Direction;
vec3 Color;
float CascadeDepth[4];
mat4 LightTransforms[4];
int Shadow;
};
uniform sampler2D ShadowMaps[4];
uniform sampler2D SpotShadowMaps[8];
uniform Light Lights[MaxLight];
uniform DirectionalLight u_DirectionalLight;
uniform int u_DisableSSAO = 0;
uniform float u_AmbientTerm;
uniform sampler2D u_PreviousFrame;
// Converts depth to World space coords.
vec3 WorldPosFromDepth(float depth) {
float z = depth * 2.0 - 1.0;
vec4 clipSpacePosition = vec4(UV * 2.0 - 1.0, z, 1.0);
vec4 viewSpacePosition = InvProjection * clipSpacePosition;
// Perspective division
viewSpacePosition /= viewSpacePosition.w;
vec4 worldSpacePosition = InvView * viewSpacePosition;
return worldSpacePosition.xyz;
}
const float PI = 3.141592653589793f;
float height_scale = 0.02f;
float DistributionGGX(vec3 N, vec3 H, float a)
{
float a2 = a * a;
float NdotH = max(dot(N, H), 0.0);
float NdotH2 = NdotH * NdotH;
float nom = a2;
float denom = (NdotH2 * (a2 - 1.0) + 1.0);
denom = PI * denom * denom;
return nom / denom;
}
float GeometrySchlickGGX(float NdotV, float k)
{
float nom = NdotV;
float denom = NdotV * (1.0 - k) + k;
return nom / denom;
}
float GeometrySmith(vec3 N, vec3 V, vec3 L, float k)
{
float NdotV = max(dot(N, V), 0.0);
float NdotL = max(dot(N, L), 0.0);
float ggx1 = GeometrySchlickGGX(NdotV, k);
float ggx2 = GeometrySchlickGGX(NdotL, k);
return ggx1 * ggx2;
}
vec3 fresnelSchlick(float cosTheta, vec3 F0)
{
return F0 + (1.0 - F0) * pow(max(1.0 - cosTheta, 0.0), 5.0);
}
vec3 fresnelSchlickRoughness(float cosTheta, vec3 F0, float roughness)
{
return F0 + (max(vec3(1.0 - roughness), F0) - F0) * pow(max(1.0 - cosTheta, 0.0), 5.0);
}
int GetCSMDepth(float depth)
{
int shadowmap = -1;
// Get CSM depth
for (int i = 0; i < 4; i++)
{
float CSMDepth = u_DirectionalLight.CascadeDepth[i];
if (depth < CSMDepth + 0.0001f)
{
shadowmap = i;
break;
}
}
return shadowmap;
}
float SampleShadowMap(sampler2D shadowMap, vec2 coords, float compare)
{
return compare < texture(shadowMap, coords.xy).r ? 1.0f : 0.0f;
}
float SampleShadowMapLinear(sampler2D shadowMap, vec2 coords, float compare, vec2 texelSize)
{
//return SampleShadowMap(shadowMap, coords.xy, compare);
vec2 pixelPos = coords / texelSize + vec2(0.5);
vec2 fracPart = fract(pixelPos);
vec2 startTexel = (pixelPos - fracPart) * texelSize;
float blTexel = SampleShadowMap(shadowMap, startTexel, compare);
float brTexel = SampleShadowMap(shadowMap, startTexel + vec2(texelSize.x, 0.0), compare);
float tlTexel = SampleShadowMap(shadowMap, startTexel + vec2(0.0, texelSize.y), compare);
float trTexel = SampleShadowMap(shadowMap, startTexel + texelSize, compare);
float mixA = mix(blTexel, tlTexel, fracPart.y);
float mixB = mix(brTexel, trTexel, fracPart.y);
return mix(mixA, mixB, fracPart.x);
}
float ShadowCalculation(vec3 FragPos, vec3 normal)
{
// Get Depth
float depth = length(FragPos - u_EyePosition);
int shadowmap = GetCSMDepth(depth);
if (shadowmap == -1)
return 1.0;
vec4 fragPosLightSpace = u_DirectionalLight.LightTransforms[shadowmap] * vec4(FragPos, 1.0f);
// perform perspective divide
vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
// transform to [0,1] range
projCoords = projCoords * 0.5 + 0.5;
// get closest depth value from light's perspective (using [0,1] range fragPosLight as coords)
// get depth of current fragment from light's perspective
float currentDepth = projCoords.z;
// check whether current frag pos is in shadow
float shadow = 0.0;
float bias = max(0.005 * (1.0 - dot(normal, u_DirectionalLight.Direction)), 0.0005);
//float pcfDepth = texture(ShadowMaps[shadowmap], vec3(projCoords.xy, currentDepth), bias);
//return SampleShadowMap(ShadowMaps[shadowmap], projCoords.xy, currentDepth - bias);
if (shadowmap <= 4)
{
const float NUM_SAMPLES = 4.f;
const float SAMPLES_START = (NUM_SAMPLES - 1.0f) / 2.0f;
const float NUM_SAMPLES_SQUARED = NUM_SAMPLES * NUM_SAMPLES;
vec2 texelSize = 1.0 / vec2(2048, 2048);
float result = 0.0f;
for (float y = -SAMPLES_START; y <= SAMPLES_START; y += 1.0f)
{
for (float x = -SAMPLES_START; x <= SAMPLES_START; x += 1.0f)
{
vec2 coordsOffset = vec2(x, y) * texelSize;
result += SampleShadowMapLinear(ShadowMaps[shadowmap], projCoords.xy + coordsOffset, currentDepth - bias, texelSize);
}
}
return result / NUM_SAMPLES_SQUARED;
}
else
{
return SampleShadowMap(ShadowMaps[shadowmap], projCoords.xy, currentDepth - bias);
}
}
float ShadowCalculationSpot(vec3 FragPos, vec3 normal, Light light)
{
// Get Depth
float depth = length(FragPos - u_EyePosition);
vec4 fragPosLightSpace = light.Transform * vec4(FragPos, 1.0f);
// perform perspective divide
vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
// transform to [0,1] range
projCoords = projCoords * 0.5 + 0.5;
// get closest depth value from light's perspective (using [0,1] range fragPosLight as coords)
// get depth of current fragment from light's perspective
float currentDepth = projCoords.z;
// check whether current frag pos is in shadow
float shadow = 0.0;
float bias = max(0.0005 * (1.0 - dot(normal, light.Direction)), 0.0005);
//float pcfDepth = texture(ShadowMaps[shadowmap], vec3(projCoords.xy, currentDepth), bias);
return SampleShadowMap(SpotShadowMaps[light.ShadowMapID], projCoords.xy, currentDepth - 0.000005);
}
void main()
{
vec3 worldPos = WorldPosFromDepth(texture(m_Depth, UV).r);
if (texture(m_Depth, UV).r == 1)
{
FragColor = vec4(0, 0, 0, 0);
return;
}
// Convert from [0, 1] to [-1, 1].
vec3 albedo = texture(m_Albedo, UV).rgb;
vec3 normal = texture(m_Normal, UV).rgb * 2.0 - 1.0;
vec4 materialSample = texture(m_Material, UV);
float metallic = materialSample.r;
float ao = materialSample.g;
float roughness = materialSample.b;
float unlit = materialSample.a;
float ssao = 0.0f;
if (u_DisableSSAO == 1)
{
ssao = 1.0f;
}
else
{
ssao = texture(m_SSAO, UV).r;
}
if (unlit > 0.1f)
{
float emissive = texture(m_Emissive, UV).r;
FragColor = vec4(albedo * ssao * emissive, 1.0);
return;
}
vec3 N = normal;
vec3 V = normalize(u_EyePosition - worldPos);
vec3 R = reflect(-V, N);
vec3 F0 = vec3(0.04);
F0 = mix(F0, albedo, metallic);
// reflectance equation
vec3 eyeDirection = normalize(u_EyePosition - worldPos);
vec3 Lo = vec3(0.0);
vec3 fog = vec3(0.0);
float shadow = 1.0f;
if (u_DirectionalLight.Shadow < 0.1f)
{
shadow = 1.f;
}
if (true)
{
vec3 L = normalize(u_DirectionalLight.Direction);
float attenuation = 1.0f;
L = normalize(u_DirectionalLight.Direction);
if(u_DirectionalLight.Shadow > 0.1f)
{
shadow *= ShadowCalculation(worldPos, N);
}
vec3 radiance = u_DirectionalLight.Color * attenuation;
vec3 H = normalize(V + L);
float NDF = DistributionGGX(N, H, roughness);
float G = GeometrySmith(N, V, L, roughness);
vec3 F = fresnelSchlick(max(dot(H, V), 0.0), F0);
vec3 nominator = NDF * G * F;
float denominator = 4 * max(dot(N, V), 0.0) * max(dot(N, L), 0.0) + 0.001; // 0.001 to prevent divide by zero.
vec3 specular = nominator / denominator;
// kS is equal to Fresnel
vec3 kS = F;
vec3 kD = vec3(1.0) - kS;
kD *= 1.0 - metallic;
// scale light by NdotL
float NdotL = max(dot(N, L), 0.0);
Lo += (kD * albedo / PI + specular) * radiance * NdotL * shadow;
}
shadow = 1.0f;
for (int i = 0; i < LightCount; i++)
{
Light light = Lights[i];
vec3 L = normalize(Lights[i].Position - worldPos);
float distance = length(light.Position - worldPos);
float attenuation = 1.0 / (distance * distance);
vec3 radiance;
if(Lights[i].Type == 1) // Point
{
radiance = Lights[i].Color * attenuation;
}
else if(Lights[i].Type == 2) // Spot
{
float theta = dot(L, normalize(-Lights[i].Direction));
float epsilon = Lights[i].InnerAngle - Lights[i].OuterAngle;
float intensity = clamp((theta - Lights[i].OuterAngle) / epsilon, 0.0, 1.0);
float shadow2 = 1.0f;
if(light.CastShadow > 0 && light.ShadowMapID >= 0)
{
shadow2 = ShadowCalculationSpot(worldPos, N, Lights[i]);
}
radiance = Lights[i].Color * intensity * shadow2;
}
// Cook-Torrance BRDF
vec3 H = normalize(V + L);
float NDF = DistributionGGX(N, H, roughness);
float G = GeometrySmith(N, V, L, roughness);
vec3 F = fresnelSchlick(max(dot(H, V), 0.0), F0);
vec3 nominator = NDF * G * F;
float denominator = 4 * max(dot(N, V), 0.0) * max(dot(N, L), 0.0) + 0.001; // 0.001 to prevent divide by zero.
vec3 specular = nominator / denominator;
// kS is equal to Fresnel
vec3 kS = F;
vec3 kD = vec3(1.0) - kS;
kD *= 1.0 - metallic;
// scale light by NdotL
float NdotL = max(dot(N, L), 0.0);
Lo += (kD * albedo / PI + specular) * radiance * NdotL;// note that we already multiplied the BRDF by the Fresnel (kS) so we won't multiply by kS again
}
/// ambient lighting (we now use IBL as the ambient term)
vec3 F = fresnelSchlickRoughness(max(dot(N, V), 0.0), F0, roughness);
vec3 kS = F;
vec3 kD = 1.0 - kS;
kD *= 1.0 - metallic;
vec3 ambient = (albedo) * ao * ssao * u_AmbientTerm;
vec3 color = (ambient) + Lo ;
// Display CSM splits..
/*float depth = length(worldPos - u_EyePosition);
int cascade = GetCSMDepth(depth, Lights[0]);
if (cascade == 0)
color *= vec3(1.0, 0.0, 0.0);
if (cascade == 1)
color *= vec3(0.0, 1.0, 0.0);
if (cascade == 2)
color *= vec3(0.0, 0.0, 1.0);
if (cascade == 3)
color *= vec3(0.0, 1.0, 1.0);
*/
FragColor = vec4(color, 1.0);
}