mirror of
https://github.com/ZDoom/gzdoom.git
synced 2024-11-23 20:43:15 +00:00
123 lines
3.4 KiB
GLSL
123 lines
3.4 KiB
GLSL
|
|
in vec2 TexCoord;
|
|
layout(location=0) out vec4 FragColor;
|
|
|
|
layout(binding=0) uniform sampler2D DepthTexture;
|
|
|
|
#if defined(MULTISAMPLE)
|
|
layout(binding=1) uniform sampler2DMS NormalTexture;
|
|
#else
|
|
layout(binding=1) uniform sampler2D NormalTexture;
|
|
#endif
|
|
|
|
#if defined(USE_RANDOM_TEXTURE)
|
|
layout(binding=2) uniform sampler2D RandomTexture;
|
|
#endif
|
|
|
|
#define PI 3.14159265358979323846
|
|
|
|
// Calculate eye space position for the specified texture coordinate
|
|
vec3 FetchViewPos(vec2 uv)
|
|
{
|
|
float z = texture(DepthTexture, uv).x;
|
|
return vec3((UVToViewA * uv + UVToViewB) * z, z);
|
|
}
|
|
|
|
#if defined(MULTISAMPLE)
|
|
vec3 SampleNormal(vec2 uv)
|
|
{
|
|
ivec2 texSize = textureSize(NormalTexture);
|
|
ivec2 ipos = ivec2(uv * vec2(texSize));
|
|
return texelFetch(NormalTexture, ipos, SampleIndex).xyz * 2.0 - 1.0;
|
|
}
|
|
#else
|
|
vec3 SampleNormal(vec2 uv)
|
|
{
|
|
ivec2 texSize = textureSize(NormalTexture, 0);
|
|
ivec2 ipos = ivec2(uv * vec2(texSize));
|
|
return texelFetch(NormalTexture, ipos, 0).xyz * 2.0 - 1.0;
|
|
}
|
|
#endif
|
|
|
|
// Look up the eye space normal for the specified texture coordinate
|
|
vec3 FetchNormal(vec2 uv)
|
|
{
|
|
vec3 normal = SampleNormal(Offset + uv * Scale);
|
|
if (length(normal) > 0.1)
|
|
{
|
|
normal = normalize(normal);
|
|
normal.z = -normal.z;
|
|
return normal;
|
|
}
|
|
else
|
|
{
|
|
return vec3(0.0);
|
|
}
|
|
}
|
|
|
|
// Compute normalized 2D direction
|
|
vec2 RotateDirection(vec2 dir, vec2 cossin)
|
|
{
|
|
return vec2(dir.x * cossin.x - dir.y * cossin.y, dir.x * cossin.y + dir.y * cossin.x);
|
|
}
|
|
|
|
vec4 GetJitter()
|
|
{
|
|
#if !defined(USE_RANDOM_TEXTURE)
|
|
return vec4(1,0,1,1);
|
|
//vec3 rand = noise3(TexCoord.x + TexCoord.y);
|
|
//float angle = 2.0 * PI * rand.x / NUM_DIRECTIONS;
|
|
//return vec4(cos(angle), sin(angle), rand.y, rand.z);
|
|
#else
|
|
return texture(RandomTexture, gl_FragCoord.xy / RANDOM_TEXTURE_WIDTH);
|
|
#endif
|
|
}
|
|
|
|
// Calculates the ambient occlusion of a sample
|
|
float ComputeSampleAO(vec3 kernelPos, vec3 normal, vec3 samplePos)
|
|
{
|
|
vec3 v = samplePos - kernelPos;
|
|
float distanceSquare = dot(v, v);
|
|
float nDotV = dot(normal, v) * inversesqrt(distanceSquare);
|
|
return clamp(nDotV - NDotVBias, 0.0, 1.0) * clamp(distanceSquare * NegInvR2 + 1.0, 0.0, 1.0);
|
|
}
|
|
|
|
// Calculates the total ambient occlusion for the entire fragment
|
|
float ComputeAO(vec3 viewPosition, vec3 viewNormal)
|
|
{
|
|
vec4 rand = GetJitter();
|
|
|
|
float radiusPixels = RadiusToScreen / viewPosition.z;
|
|
float stepSizePixels = radiusPixels / (NUM_STEPS + 1.0);
|
|
|
|
const float directionAngleStep = 2.0 * PI / NUM_DIRECTIONS;
|
|
float ao = 0.0;
|
|
|
|
for (float directionIndex = 0.0; directionIndex < NUM_DIRECTIONS; ++directionIndex)
|
|
{
|
|
float angle = directionAngleStep * directionIndex;
|
|
|
|
vec2 direction = RotateDirection(vec2(cos(angle), sin(angle)), rand.xy);
|
|
float rayPixels = (rand.z * stepSizePixels + 1.0);
|
|
|
|
for (float StepIndex = 0.0; StepIndex < NUM_STEPS; ++StepIndex)
|
|
{
|
|
vec2 sampleUV = round(rayPixels * direction) * InvFullResolution + TexCoord;
|
|
vec3 samplePos = FetchViewPos(sampleUV);
|
|
ao += ComputeSampleAO(viewPosition, viewNormal, samplePos);
|
|
rayPixels += stepSizePixels;
|
|
}
|
|
}
|
|
|
|
ao *= AOMultiplier / (NUM_DIRECTIONS * NUM_STEPS);
|
|
return clamp(1.0 - ao * 2.0, 0.0, 1.0);
|
|
}
|
|
|
|
void main()
|
|
{
|
|
vec3 viewPosition = FetchViewPos(TexCoord);
|
|
vec3 viewNormal = FetchNormal(TexCoord);
|
|
float occlusion = viewNormal != vec3(0.0) ? ComputeAO(viewPosition, viewNormal) * AOStrength + (1.0 - AOStrength) : 1.0;
|
|
|
|
FragColor = vec4(occlusion, viewPosition.z, 0.0, 1.0);
|
|
}
|