vkdoom_m/wadsrc/static/shaders/lightmap/trace_light.glsl
Magnus Norddahl 60cdb871d2 Add light bounce
2024-02-26 17:00:28 +01:00

85 lines
2.6 KiB
GLSL

#include <shaders/lightmap/montecarlo.glsl>
vec4 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec4 rayColor);
vec3 TraceLight(vec3 origin, vec3 normal, LightInfo light, float extraDistance)
{
const float minDistance = 0.01;
vec3 incoming = vec3(0.0);
float dist = distance(light.RelativeOrigin, origin) + extraDistance;
if (dist > minDistance && dist < light.Radius)
{
vec3 dir = normalize(light.RelativeOrigin - origin);
float distAttenuation = max(1.0 - (dist / light.Radius), 0.0);
float angleAttenuation = max(dot(normal, dir), 0.0);
float spotAttenuation = 1.0;
if (light.OuterAngleCos > -1.0)
{
float cosDir = dot(dir, light.SpotDir);
spotAttenuation = smoothstep(light.OuterAngleCos, light.InnerAngleCos, cosDir);
spotAttenuation = max(spotAttenuation, 0.0);
}
float attenuation = distAttenuation * angleAttenuation * spotAttenuation;
if (attenuation > 0.0)
{
vec4 rayColor = vec4(light.Color.rgb * (attenuation * light.Intensity), 1.0);
#if defined(USE_SOFTSHADOWS)
vec3 v = (abs(dir.x) > abs(dir.y)) ? vec3(0.0, 1.0, 0.0) : vec3(1.0, 0.0, 0.0);
vec3 xdir = normalize(cross(dir, v));
vec3 ydir = cross(dir, xdir);
float lightsize = 10;
int step_count = 10;
for (int i = 0; i < step_count; i++)
{
vec2 gridoffset = getVogelDiskSample(i, step_count, gl_FragCoord.x + gl_FragCoord.y * 13.37) * lightsize;
vec3 pos = light.Origin + xdir * gridoffset.x + ydir * gridoffset.y;
incoming.rgb += TracePointLightRay(origin, pos, minDistance, rayColor).rgb / float(step_count);
}
#else
incoming.rgb += TracePointLightRay(origin, light.Origin, minDistance, rayColor).rgb;
#endif
}
}
return incoming;
}
vec4 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec4 rayColor)
{
vec3 dir = normalize(lightpos - origin);
float tmax = distance(origin, lightpos);
for (int i = 0; i < 3; i++)
{
TraceResult result = TraceFirstHit(origin, tmin, dir, tmax);
// We hit nothing. Point light is visible.
if (result.primitiveIndex == -1)
return rayColor;
SurfaceInfo surface = GetSurface(result.primitiveIndex);
// Blend with surface texture
rayColor = BlendTexture(surface, GetSurfaceUV(result.primitiveIndex, result.primitiveWeights), rayColor);
// Stop if it isn't a portal, or there is no light left
if (surface.PortalIndex == 0 || rayColor.r + rayColor.g + rayColor.b <= 0.0)
return vec4(0.0);
// Move to surface hit point
origin += dir * result.t;
tmax -= result.t;
// Move through the portal, if any
TransformRay(surface.PortalIndex, origin, dir);
}
return vec4(0.0);
}