pex-renderer/shaders/chunks/light-directional.glsl.js

Physically Based Renderer for Pex

module.exports = /* glsl */ `
#if NUM_DIRECTIONAL_LIGHTS > 0

struct DirectionalLight {
  vec3 direction;
  vec4 color;
  mat4 projectionMatrix;
  mat4 viewMatrix;
  bool castShadows;
  float near;
  float far;
  float bias;
  vec2 shadowMapSize;
};

uniform DirectionalLight uDirectionalLights[NUM_DIRECTIONAL_LIGHTS];
uniform sampler2D uDirectionalLightShadowMaps[NUM_DIRECTIONAL_LIGHTS]; //TODO: is it ok to sample depth texture as sampler2D?

void EvaluateDirectionalLight(inout PBRData data, DirectionalLight light, sampler2D shadowMap) {
  vec4 lightViewPosition = light.viewMatrix * vec4(vPositionWorld, 1.0);
  float lightDistView = -lightViewPosition.z;
  vec4 lightDeviceCoordsPosition = light.projectionMatrix * lightViewPosition;
  vec3 lightDeviceCoordsPositionNormalized = lightDeviceCoordsPosition.xyz / lightDeviceCoordsPosition.w;
  vec2 lightUV = lightDeviceCoordsPositionNormalized.xy * 0.5 + 0.5;

  float illuminated = bool(light.castShadows) ? getShadow(shadowMap, light.shadowMapSize, lightUV, lightDistView - light.bias, light.near, light.far) : 1.0;

  if (illuminated > 0.0) {
    Light l;
    l.l = -light.direction;
    l.color = light.color;
    l.attenuation = 1.0;
    getSurfaceShading(data, l, illuminated);
  }
}
#endif
`