quakeforge/libs/video/renderer/vulkan/shader/lighting.frag
Bill Currie afa84afc79 [vulkan] Abandon light splats
They were an interesting idea and might be useful in the future, but
they don't work as well as I had hoped for quake's maps due to the
overlapping light volumes causing contention while doing the additive
blends in the frame buffer. The cause was made obvious when testing in
the marcher map: most of its over 400 lights have infinite radius thus
require full screen passes: all those passes fighting for the frame
buffer did very nasty things to performance. However, light splats might be
useful for many small, non-overlapping light volumes, thus the code is
being kept (and I like the cleanups that came with it).
2023-06-28 13:26:37 +09:00

93 lines
2.5 KiB
GLSL

#version 450
#extension GL_GOOGLE_include_directive : enable
#include "lighting.h"
layout (input_attachment_index = 0, set = 2, binding = 0) uniform subpassInput depth;
layout (input_attachment_index = 1, set = 2, binding = 1) uniform subpassInput color;
layout (input_attachment_index = 2, set = 2, binding = 2) uniform subpassInput emission;
layout (input_attachment_index = 3, set = 2, binding = 3) uniform subpassInput normal;
layout (input_attachment_index = 4, set = 2, binding = 4) uniform subpassInput position;
layout (set = 3, binding = 0) uniform sampler2DArrayShadow shadowCascade[MaxLights];
layout (set = 3, binding = 0) uniform sampler2DShadow shadowPlane[MaxLights];
layout (set = 3, binding = 0) uniform samplerCubeShadow shadowCube[MaxLights];
layout (location = 0) out vec4 frag_color;
float
spot_cone (LightData light, vec3 incoming)
{
vec3 dir = light.direction.xyz;
float cone = light.direction.w;
float spotdot = dot (incoming, dir);
return 1 - smoothstep (cone, .995 * cone + 0.005, spotdot);
}
float
diffuse (vec3 incoming, vec3 normal)
{
float lightdot = dot (incoming, normal);
return clamp (lightdot, 0, 1);
}
float
shadow_cascade (sampler2DArrayShadow map)
{
return 1;
}
float
shadow_plane (sampler2DShadow map)
{
return 1;
}
float
shadow_cube (samplerCubeShadow map)
{
return 1;
}
void
main (void)
{
//float d = subpassLoad (depth).r;
vec3 c = subpassLoad (color).rgb;
vec3 e = subpassLoad (emission).rgb;
vec3 n = subpassLoad (normal).rgb;
vec3 p = subpassLoad (position).rgb;
vec3 light = vec3 (0);
//vec3 minLight = vec3 (0);
for (int i = 0; i < lightCount; i++) {
LightData l = lights[i];
vec3 dir = l.position.xyz - l.position.w * p;
float r2 = dot (dir, dir);
vec4 a = l.attenuation;
if (l.position.w * a.w * a.w * r2 >= 1) {
continue;
}
vec4 r = vec4 (r2, sqrt(r2), 1, 0);
vec3 incoming = dir / r.y;
float I = (1 - a.w * r.y) / dot (a, r);
/*int shadow = lights[i].data & ShadowMask;
if (shadow == ST_CASCADE) {
I *= shadow_cascade (shadowCascade[i]);
} else if (shadow == ST_PLANE) {
I *= shadow_plane (shadowPlane[i]);
} else if (shadow == ST_CUBE) {
I *= shadow_cube (shadowCube[i]);
}*/
float namb = dot(l.direction.xyz, l.direction.xyz);
I *= spot_cone (l, incoming) * diffuse (incoming, n);
I = mix (1, I, namb);
light += I * l.color.w * l.color.xyz;
}
//light = max (light, minLight);
frag_color = vec4 (light, 1);
}