Add cutoff to flashlight

src/drawables/lights/flashlight.ts

@@ -12,6 +12,7 @@ export class Flashlight extends LightDrawable {
       color: 'flashlightColors',
       intensity: 'flashlightIntensities',
       direction: 'flashlightDirections',
+      startCutoff: 'flashlightStartCutoffs',
     },
     uniformCountMacroName: 'FLASHLIGHT_COUNT',
     shaderCombinationSteps: [0, 1, 2, 4],
@@ -27,7 +28,8 @@ export class Flashlight extends LightDrawable {
     center: vec2,
     color: vec3,
     intensity: number,
-    public direction: vec2
+    public direction: vec2,
+    public startCutoff = 0
   ) {
     super(center, color, intensity);
   }
@@ -36,6 +38,7 @@ export class Flashlight extends LightDrawable {
     return {
       ...super.getObjectToSerialize(transform2d, transform1d),
       direction: vec2.normalize(vec2.create(), this.direction),
+      startCutoff: this.startCutoff * transform1d,
     };
   }
 }

src/graphics/rendering/shaders/shading-fs.glsl

@@ -59,6 +59,7 @@ float shadowTransparency(float startingDistance, float lightCenterDistance, vec2
     uniform float flashlightIntensities[FLASHLIGHT_COUNT];
     uniform vec3 flashlightColors[FLASHLIGHT_COUNT];
     uniform vec2 flashlightDirections[FLASHLIGHT_COUNT];
+    uniform float flashlightStartCutoffs[FLASHLIGHT_COUNT];
 
     in vec2 flashlightActualDirections[FLASHLIGHT_COUNT];
 
@@ -114,8 +115,16 @@ void main() {
         vec2 originalDirection = normalize(flashlightActualDirections[i]);
 
         float lightCenterDistance;
-        vec3 lightColorAtPosition = colorInPosition(i, originalDirection, lightCenterDistance);
+        vec3 lightColorAtPosition = colorInPosition(
+            i,
+            originalDirection,
+            lightCenterDistance
+        );
         
+        if (lightCenterDistance < flashlightStartCutoffs[i]) {
+            continue;
+        }
+
         vec2 direction = originalDirection / squareToAspectRatioTimes2;
 
         if (length(lightColorAtPosition) < 0.0) {