ioq3quest/code/renderergl2/glsl/pshadow_fp.glsl
2020-09-06 13:40:32 +02:00

79 lines
1.8 KiB
GLSL

precision mediump sampler2D;
uniform sampler2D u_ShadowMap;
uniform vec3 u_LightForward;
uniform vec3 u_LightUp;
uniform vec3 u_LightRight;
uniform vec4 u_LightOrigin;
uniform float u_LightRadius;
varying vec3 var_Position;
varying vec3 var_Normal;
void main()
{
vec3 lightToPos = var_Position - u_LightOrigin.xyz;
vec2 st = vec2(-dot(u_LightRight, lightToPos), dot(u_LightUp, lightToPos));
float fade = length(st);
#if defined(USE_DISCARD)
if (fade >= 1.0)
{
discard;
}
#endif
fade = clamp(8.0 - fade * 8.0, 0.0, 1.0);
st = st * 0.5 + vec2(0.5);
#if defined(USE_SOLID_PSHADOWS)
float intensity = max(sign(u_LightRadius - length(lightToPos)), 0.0);
#else
float intensity = clamp((1.0 - dot(lightToPos, lightToPos) / (u_LightRadius * u_LightRadius)) * 2.0, 0.0, 1.0);
#endif
float lightDist = length(lightToPos);
float dist;
#if defined(USE_DISCARD)
if (dot(u_LightForward, lightToPos) <= 0.0)
{
discard;
}
if (dot(var_Normal, lightToPos) > 0.0)
{
discard;
}
#else
intensity *= max(sign(dot(u_LightForward, lightToPos)), 0.0);
intensity *= max(sign(-dot(var_Normal, lightToPos)), 0.0);
#endif
intensity *= fade;
float part;
#if defined(USE_PCF)
part = float(texture2D(u_ShadowMap, st + vec2(-1.0/512.0, -1.0/512.0)).r != 1.0);
part += float(texture2D(u_ShadowMap, st + vec2( 1.0/512.0, -1.0/512.0)).r != 1.0);
part += float(texture2D(u_ShadowMap, st + vec2(-1.0/512.0, 1.0/512.0)).r != 1.0);
part += float(texture2D(u_ShadowMap, st + vec2( 1.0/512.0, 1.0/512.0)).r != 1.0);
#else
part = float(texture2D(u_ShadowMap, st).r != 1.0);
#endif
if (part <= 0.0)
{
discard;
}
#if defined(USE_PCF)
intensity *= part * 0.25;
#else
intensity *= part;
#endif
gl_FragColor.rgb = vec3(0);
gl_FragColor.a = clamp(intensity, 0.0, 0.75);
}