MODERN: Make use of precalculated lm vlen in lightmap shader.

Also better readability of using vec4 to match host side float[4], even if
alignment should have worked out just fine before.

src/glm_brushmodel.c

@@ -72,6 +72,8 @@ void GLM_CreateBrushModelVAO(void)
 			surfaces[i].normal[3] = surf->plane->dist;
 			memcpy(surfaces[i].lm_vecs0, surf->lmvecs[0], sizeof(surf->lmvecs[0]));
 			memcpy(surfaces[i].lm_vecs1, surf->lmvecs[1], sizeof(surf->lmvecs[1]));
+			surfaces[i].lm_vecs0[3] = surf->lmvlen[0];
+			surfaces[i].lm_vecs1[3] = surf->lmvlen[1];
 		}
 		buffers.Create(r_buffer_brushmodel_surface_data, buffertype_storage, "brushmodel-surfs", cl.worldmodel->numsurfaces * sizeof(vbo_world_surface_t), surfaces, bufferusage_constant_data);
 		Q_free(surfaces);

src/glsl/common.glsl

@@ -116,6 +116,6 @@ struct AliasModel {
 
 struct model_surface {
 	vec4 normal;
-	vec3 vecs0;
-	vec3 vecs1;
+	vec4 vecs0;
+	vec4 vecs1;
 };

src/glsl/lighting.compute.glsl

@@ -42,14 +42,11 @@ void main()
 			blocklight.a = 0;
 
 			vec4 Plane = surfaces[surfaceNumber].normal;
-			vec3 PlaneMins0 = surfaces[surfaceNumber].vecs0;
-			vec3 PlaneMins1 = surfaces[surfaceNumber].vecs1;
+			vec4 PlaneMins0 = surfaces[surfaceNumber].vecs0;
+			vec4 PlaneMins1 = surfaces[surfaceNumber].vecs1;
 
-			float vlen0 = length(PlaneMins0);
-			vlen0 = vlen0 > 0.0f ? 1.0f / vlen0 : 0;
-
-			float vlen1 = length(PlaneMins1);
-			vlen1 = vlen1 > 0.0f ? 1.0f / vlen1 : 0;
+			float vlen0 = PlaneMins0.w;
+			float vlen1 = PlaneMins1.w;
 
 			// Build static lights: default to black
 			vec4 baseLightmap = vec4(0, 0, 0, 0);
@@ -80,7 +77,7 @@ void main()
 					minlight = rad - minlight;
 
 					vec3 impact = lightPositions[i].xyz - Plane.xyz * dist;
-					vec2 local = vec2(dot(impact, PlaneMins0), dot(impact, PlaneMins1));
+					vec2 local = vec2(dot(impact, PlaneMins0.xyz), dot(impact, PlaneMins1.xyz));
 
 					int sd = int(abs(local[0] - sdelta) * vlen0); // sdelta = s * (1 << surf->lmshift) + surf->texturemins[0] - surf->lmvecs[0][3];
 					int td = int(abs(local[1] - tdelta) * vlen1); // tdelta = t * (1 << surf->lmshift) + surf->texturemins[1] - surf->lmvecs[1][3];