From 091b714e4c08fa84c638b4360f274bd1b8e99d9e Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Tue, 3 Jan 2012 20:36:07 +0900
Subject: [PATCH] Implement dynamic lighting.

This uses the same calculations as the software renderer. However, as the
lightmap calculations are not done yet, if there is no dlight in the
vicinity, there will be no light. demo1 is pretty cool to watch :)
---
 libs/video/renderer/glsl/glsl_alias.c | 35 ++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/libs/video/renderer/glsl/glsl_alias.c b/libs/video/renderer/glsl/glsl_alias.c
index d676aec14..34ef30934 100644
--- a/libs/video/renderer/glsl/glsl_alias.c
+++ b/libs/video/renderer/glsl/glsl_alias.c
@@ -146,6 +146,33 @@ R_InitAlias (void)
 	GL_ResolveShaderParam (quake_mdl.program, &quake_mdl.shadelight);
 	GL_ResolveShaderParam (quake_mdl.program, &quake_mdl.lightvec);
 }
+
+static void
+calc_lighting (entity_t *ent, float *ambient, float *shadelight,
+			   vec3_t lightvec)
+{
+	unsigned    i;
+	float       add;
+	vec3_t      dist;
+
+	VectorSet ( -1, 0, 0, lightvec);	//FIXME
+	*ambient = max (R_LightPoint (ent->origin), max (ent->model->min_light,
+													 ent->min_light) * 128);
+	*shadelight = *ambient;
+
+	for (i = 0; i < r_maxdlights; i++) {
+		if (r_dlights[i].die >= r_realtime) {
+			VectorSubtract (ent->origin, r_dlights[i].origin, dist);
+			add = r_dlights[i].radius - VectorLength (dist);
+			if (add > 0)
+				*ambient += add;
+		}
+	}
+	if (*ambient >= 128)
+		*ambient = 128;
+	if (*shadelight > 192 - *ambient)
+		*shadelight = 192 - *ambient;
+}
 //#define TETRAHEDRON
 void
 R_DrawAlias (void)
@@ -165,9 +192,9 @@ R_DrawAlias (void)
 	};
 #endif
 	static quat_t color = { 1, 1, 1, 1};
-	static vec3_t lightvec = { -1, 0, 0 };	//FIXME
-	float       ambient = 128;				//FIXME
-	float       shadelight = 64;			//FIXME
+	static vec3_t lightvec;
+	float       ambient;
+	float       shadelight;
 	float       skin_size[2];
 	entity_t   *ent = currententity;
 	model_t    *model = ent->model;
@@ -180,6 +207,8 @@ R_DrawAlias (void)
 
 	hdr = Cache_Get (&model->cache);
 
+	calc_lighting (ent, &ambient, &shadelight, lightvec);
+
 	// we need only the rotation for normals.
 	VectorCopy (ent->transform + 0, norm_mat + 0);
 	VectorCopy (ent->transform + 4, norm_mat + 3);