point light

5 files changed, 86 insertions, 7 deletions

diff --git a/c2.cpp b/c2.cpp
index 1262241..58e33ff 100644
--- a/c2.cpp
+++ b/c2.cpp
@@ -761,6 +761,24 @@ struct C2 : public App {
 			light.caster = true;
 		}
 		{
+			auto l = world->create_entity();
+			auto [t, light] = world->add<Transform, Point_Light>(l);
+			t.mat = m4f::translate(m4f::identity(), v3f(-3.0f, 1.0f, 0.0f));
+			light.colour = v3f(1.0f, 0.0f, 0.0f);
+			light.brightness = 5.0f;
+			light.caster = true;
+			light.range = 5.0f;
+		}
+		{
+			auto l = world->create_entity();
+			auto [t, light] = world->add<Transform, Point_Light>(l);
+			t.mat = m4f::translate(m4f::identity(), v3f(3.0f, 2.0f, 0.0f));
+			light.colour = v3f(0.0f, 1.0f, 0.0f);
+			light.brightness = 5.0f;
+			light.caster = true;
+			light.range = 3.0f;
+		}
+		{
 			box_col = make_box(&asset_arena, v3f(1.0f, 1.0f, 1.0f));
 			floor_col = make_box(&asset_arena, v3f(10.0f, 0.1f, 10.0f));
 			box = world->create_entity();
diff --git a/intermediate/forward.h b/intermediate/forward.h
index 7c4c9d3..377a3cb 100644
--- a/intermediate/forward.h
+++ b/intermediate/forward.h
@@ -5,7 +5,7 @@
 [struct]
 name: Light
 [variable]
-name: dir
+name: pos
 type: vec3
 [variable]
 name: brightness
@@ -16,6 +16,12 @@ type: vec3
 [variable]
 name: caster_id
 type: int
+[variable]
+name: type
+type: int
+[variable]
+name: range
+type: float
 
 [struct]
 name: Caster
@@ -41,4 +47,9 @@ type: Globals
 stage: fragment
 
 #endif
+
+/* match Light::Type in lighting.hpp */
+#define LT_SUN 0
+#define LT_POINT 1
+
 #endif
diff --git a/intermediate/surface.glsl b/intermediate/surface.glsl
index 71a4307..79f5f65 100644
--- a/intermediate/surface.glsl
+++ b/intermediate/surface.glsl
@@ -244,8 +244,23 @@ void main() {
 	vec3 light = 0.0.xxx;
 	for (i = 0; i < globals.light_count; i++) {
 		Light l = lights[i];
-		vec3 light_dir = l.dir;
-		float cos_theta_i = max(dot(nrm, light_dir), 0.0);
+		vec3 light_dir;
+		float cos_theta_i, atten;
+		switch (l.type) {
+			case LT_SUN:
+				light_dir = l.pos;
+				cos_theta_i = max(dot(nrm, light_dir), 0.0);
+				atten = 1.0;
+				break;
+			case LT_POINT: {
+				float d;
+				light_dir = p - l.pos;
+				d = length(light_dir);
+				atten = max(d, 0.01);
+				atten = 1.0 / (atten * atten);
+				light_dir /= d;
+			} break;
+		}
 		vec3 diffuse = base_diffuse * cos_theta_i;
 		vec3 spec =
 			spec_col *
@@ -254,7 +269,7 @@ void main() {
 		float shadow = 1.0f;
 		if (l.caster_id >= 0)
 			shadow = get_shadow(l, p);
-		light += (diffuse + spec) * l.brightness * l.colour * shadow;
+		light += (diffuse + spec) * atten * l.brightness * l.colour * shadow;
 	}
 
 	colour = vec4(ambient + light, 1.0);
diff --git a/lighting.cpp b/lighting.cpp
index 0e41ddd..bf01831 100644
--- a/lighting.cpp
+++ b/lighting.cpp
@@ -1,6 +1,7 @@
 #include "lighting.hpp"
 #include "model.hpp"
 #include "renderer.hpp"
+#include "scene.hpp"
 #include "world.hpp"
 
 extern "C" {
@@ -10,10 +11,13 @@ extern "C" {
 
 /* needs to match surface shader */
 struct GPU_Light {
-	v3f dir;
+	v3f pos;
 	float brightness;
 	v3f colour;
 	int caster_id;
+	int type;
+	float range;
+	int pad[2];
 };
 
 struct GPU_Caster {
@@ -102,11 +106,12 @@ void Lighting::write_bufs(
 		Sun_Light& l = v.get<Sun_Light>();
 		if (count >= max_lights) {
 			print_war("Over light limit.\n");
-			return;
+			goto cancel;
 		}
+		gl.type = (int)Light::Type::sun;
 		gl.brightness = l.brightness;
 		gl.colour = l.colour;
-		gl.dir = l.dir;
+		gl.pos = l.dir;
 		if (l.caster && ccount < max_shadows) {
 			int cid = ccount++;
 			GPU_Caster& c = cdst[cid];
@@ -122,6 +127,27 @@ void Lighting::write_bufs(
 			gl.caster_id = -1;
 		ldst[count++] = gl;
 	}
+	for (auto v : w.view<Transform, Point_Light>()) {
+		GPU_Light gl;
+		Transform& t = v.get<Transform>();
+		Point_Light& l = v.get<Point_Light>();
+		if (count >= max_lights) {
+			print_war("Over light limit.\n");
+			goto cancel;
+		}
+		gl.type = (int)Light::Type::point;
+		gl.brightness = l.brightness;
+		gl.colour = l.colour;
+		gl.pos = v3f(
+			t.mat.m[3][0],
+			t.mat.m[3][1],
+			t.mat.m[3][2]
+		);
+		gl.caster_id = -1;
+		gl.range = l.range;
+		ldst[count++] = gl;
+	}
+cancel:
 	light_count = count;
 	caster_count = ccount;
 }
diff --git a/lighting.hpp b/lighting.hpp
index ccd08d3..38e95ae 100644
--- a/lighting.hpp
+++ b/lighting.hpp
@@ -41,6 +41,11 @@ struct Lighting {
 };
 
 struct Light {
+	enum class Type {
+		sun,
+		point
+	};
+
 	v3f colour;
 	float brightness;
 	bool caster;
@@ -50,4 +55,8 @@ struct Sun_Light : Light {
 	v3f dir;
 };
 
+struct Point_Light : Light {
+	float range;
+};
+
 #endif