fix: spot light attenuation issues

Author: hoffstadt

extensions/pl_renderer_ext.c

@@ -3282,7 +3282,7 @@ pl_renderer_debug_draw_lights(plView* ptView, const plLightComponent* sbtLights,
             else if(sbtLights[i].tType == PL_LIGHT_TYPE_SPOT)
             {
                 plCone tCone0 = {
-                    .fRadius = tanf(sbtLights[i].fOuterConeAngle) * sbtLights[i].fRange,
+                    .fRadius = tanf(sbtLights[i].fOuterConeAngle * 0.5f) * sbtLights[i].fRange,
                     .tTipPos = sbtLights[i].tPosition,
                     .tBasePos = pl_add_vec3(sbtLights[i].tPosition, pl_mul_vec3_scalarf(sbtLights[i].tDirection, sbtLights[i].fRange))
                 };

shaders/lighting.glsl

@@ -113,16 +113,19 @@ filterPCF(vec4 sc, vec2 offset, int textureIndex)
 	float dy = scale * 1.0 / (float(texDim.y));
 
 	float shadowFactor = 0.0;
-	int count = 0;
+	// int count = 0;
 	int range = 1;
 
-	for (int x = -range; x <= range; x++) {
-		for (int y = -range; y <= range; y++) {
+	for (int x = -range; x <= range; x++)
+    {
+		for (int y = -range; y <= range; y++)
+        {
 			shadowFactor += textureProj(sc, vec2(dx*x, dy*y) + offset, textureIndex);
-			count++;
+			// count++;
 		}
 	}
-	return shadowFactor / count;
+	// return shadowFactor / count;
+	return shadowFactor / 4.0;
 }
 
 float
@@ -134,16 +137,19 @@ filterPCF2(vec4 sc, vec2 offset, int textureIndex)
 	float dy = scale * 1.0 / (float(texDim.y));
 
 	float shadowFactor = 0.0;
-	int count = 0;
+	// int count = 0;
 	int range = 1;
 
-	for (int x = -range; x <= range; x++) {
-		for (int y = -range; y <= range; y++) {
+	for (int x = -range; x <= range; x++)
+    {
+		for (int y = -range; y <= range; y++)
+        {
 			shadowFactor += textureProj2(sc, vec2(dx*x, dy*y) + offset, textureIndex);
-			count++;
+			// count++;
 		}
 	}
-	return shadowFactor / count;
+	// return shadowFactor / count;
+	return shadowFactor / 4.0;
 }
 
 #endif // LIGHTING_GLSL

shaders/lights.glsl

@@ -4,16 +4,14 @@
 #include "pl_shader_interop_renderer.h"
 
 float
-getRangeAttenuation(float range2, float dist2)
+getRangeAttenuation(float range, float distance)
 {
-    if (range2 <= 0.0)
+    if (range <= 0.0)
     {
         // negative range means unlimited
-        return 1.0 / dist2;
+        return 1.0 / pow(distance, 2.0);
     }
-    float dist_per_range = dist2 / range2;
-    dist_per_range *= dist_per_range;
-    return max(min(1.0 - dist_per_range, 1.0), 0.0) / dist2;
+    return max(min(1.0 - pow(distance / range, 4.0), 1.0), 0.0) / pow(distance, 2.0);
 }
 
 // https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Khronos/KHR_lights_punctual/README.md#inner-and-outer-cone-angles
@@ -39,11 +37,11 @@ getLightIntensity(plGpuLight light, vec3 pointToLight)
     float rangeAttenuation = 1.0;
     float spotAttenuation = 1.0;
 
-    if (light.iType != 0)
+    if (light.iType != PL_LIGHT_TYPE_DIRECTIONAL)
     {
-        rangeAttenuation = getRangeAttenuation(light.fRange * light.fRange, pointToLight.x * pointToLight.x + pointToLight.y * pointToLight.y + pointToLight.z * pointToLight.z);
+        rangeAttenuation = getRangeAttenuation(light.fRange, length(pointToLight));
     }
-    if (light.iType == 2)
+    if (light.iType == PL_LIGHT_TYPE_SPOT)
     {
         spotAttenuation = getSpotAttenuation(pointToLight, light.tDirection, light.fOuterConeCos, light.fInnerConeCos);
     }