Merge pull request #3 from andrewjhaman/main

Fit Shadows to Frustum

main.c

@@ -4996,7 +4996,45 @@ float round_to_nearest(float input, float round_target)
     return result;
 }
 
-Shadow_Volume_Params calculate_shadow_volume_params(Vec3 light_dir) 
+
+typedef struct
+{
+	//For now we consider all vertices on the near plane to be equal to the camera position, and store that at vertices[0];
+	Vec3 vertices[5];
+} FrustumVertices;
+
+FrustumVertices get_frustum_vertices(Vec3 cam_pos, Vec3 cam_forward, Vec3 cam_right) {
+	FrustumVertices result = {0};
+
+	float aspect_ratio = (float)sapp_width() / (float)sapp_height();
+
+	const int num_frustum_vertices = sizeof(result.vertices)/sizeof(result.vertices[0]);
+
+	const float cascade_distance = FAR_PLANE_DISTANCE;
+
+	Vec2 far_plane_half_dims;
+	far_plane_half_dims.y = cascade_distance * tanf(FIELD_OF_VIEW * 0.5f);
+	far_plane_half_dims.x = far_plane_half_dims.y * aspect_ratio;
+
+	Vec3 cam_up = Cross(cam_right, cam_forward); 
+
+	Vec3 far_plane_centre = AddV3(cam_pos, MulV3F(cam_forward, cascade_distance));
+	Vec3 far_plane_offset_to_right_side  = MulV3F(cam_right, far_plane_half_dims.x);
+	Vec3 far_plane_offset_to_top_side    = MulV3F(cam_up   , far_plane_half_dims.y);
+	Vec3 far_plane_offset_to_left_side   = MulV3F(far_plane_offset_to_right_side, -1.0); 
+	Vec3 far_plane_offset_to_bot_side    = MulV3F(far_plane_offset_to_top_side  , -1.0);   
+
+	result.vertices[0] = cam_pos;
+	result.vertices[1] = AddV3(far_plane_centre, AddV3(far_plane_offset_to_bot_side, far_plane_offset_to_left_side ));
+	result.vertices[2] = AddV3(far_plane_centre, AddV3(far_plane_offset_to_bot_side, far_plane_offset_to_right_side));
+	result.vertices[3] = AddV3(far_plane_centre, AddV3(far_plane_offset_to_top_side, far_plane_offset_to_right_side));
+	result.vertices[4] = AddV3(far_plane_centre, AddV3(far_plane_offset_to_top_side, far_plane_offset_to_left_side ));
+
+
+	return result;
+}
+
+Shadow_Volume_Params calculate_shadow_volume_params(Vec3 light_dir, Vec3 cam_pos, Vec3 cam_forward, Vec3 cam_right) 
 {
 	Shadow_Volume_Params result = {0};
 
@@ -5009,55 +5047,34 @@ Shadow_Volume_Params calculate_shadow_volume_params(Vec3 light_dir)
 	//To make up for this, we add an extra padding-skirt to the bounds.
 	Mat4 light_space_matrix = LookAt_RH((Vec3){0}, light_dir, V3(0, 1, 0));
 
-	Vec3 scene_min = V3( INFINITY,  INFINITY,  INFINITY);
-	Vec3 scene_max = V3(-INFINITY, -INFINITY, -INFINITY);
+	Vec3 frustum_min = V3( INFINITY,  INFINITY,  INFINITY);
+	Vec3 frustum_max = V3(-INFINITY, -INFINITY, -INFINITY);
 
-	for(PlacedMesh *cur = level_threedee.placed_mesh_list; cur; cur = cur->next)
-	{
-		Vec3 p = MulM4V3(light_space_matrix, cur->t.offset);
+	FrustumVertices frustum_vertices_worldspace = get_frustum_vertices(cam_pos, cam_forward, cam_right);
+	const int num_frustum_vertices = sizeof(frustum_vertices_worldspace.vertices)/sizeof(frustum_vertices_worldspace.vertices[0]);
 
-		scene_min.x = fminf(scene_min.x, p.x);
-		scene_max.x = fmaxf(scene_max.x, p.x);
+	for (int i = 0; i < num_frustum_vertices; ++i) {
+		Vec3 p = frustum_vertices_worldspace.vertices[i];
 
-		scene_min.y = fminf(scene_min.y, p.y);
-		scene_max.y = fmaxf(scene_max.y, p.y);
-		
-		scene_min.z = fminf(scene_min.z, p.z);
-		scene_max.z = fmaxf(scene_max.z, p.z);
-	}
+		p = MulM4V3(light_space_matrix, p);
 
-	ENTITIES_ITER(gs.entities)
-	{
-		if(it->is_npc || it->is_character)
-		{
-			Transform draw_with = entity_transform(it);
-			Vec3 p = MulM4V3(light_space_matrix, draw_with.offset);
+		frustum_min.x = fminf(frustum_min.x, p.x);
+		frustum_max.x = fmaxf(frustum_max.x, p.x);
 
-			scene_min.x = fminf(scene_min.x, p.x);
-			scene_max.x = fmaxf(scene_max.x, p.x);
-	
-			scene_min.y = fminf(scene_min.y, p.y);
-			scene_max.y = fmaxf(scene_max.y, p.y);
-			
-			scene_min.z = fminf(scene_min.z, p.z);
-			scene_max.z = fmaxf(scene_max.z, p.z);
-		}
+		frustum_min.y = fminf(frustum_min.y, p.y);
+		frustum_max.y = fmaxf(frustum_max.y, p.y);
+		
+		frustum_min.z = fminf(frustum_min.z, p.z);
+		frustum_max.z = fmaxf(frustum_max.z, p.z);	
 	}
 
-	//pad to account for entity width
-	float pad = 2.5f;
-
-	scene_min.x -= pad;
-	scene_min.y -= pad;
 
-	scene_max.x += pad;
-	scene_max.y += pad;
 
-	result.l = scene_min.x;
-	result.r = scene_max.x;
+	result.l = frustum_min.x;
+	result.r = frustum_max.x;
 
-	result.b = scene_min.y;
-	result.t = scene_max.y;
+	result.b = frustum_min.y;
+	result.t = frustum_max.y;
 
 	float w = result.r - result.l;
 	float h = result.t - result.b;
@@ -5094,6 +5111,54 @@ Shadow_Volume_Params calculate_shadow_volume_params(Vec3 light_dir)
 	return result;
 }
 
+
+void debug_draw_img(sg_image img, int index) {
+    draw_quad((DrawParams){quad_at(V2(512.0f*index, 512.0), V2(512.0, 512.0)), IMG(state.shadows.color_img), WHITE, .layer=LAYER_UI});
+}
+
+void debug_draw_img_with_border(sg_image img, int index) {
+    float bs = 50.0;
+    draw_quad((DrawParams){quad_at(V2(512.0f*index, 512.0), V2(512.0, 512.0)), state.shadows.color_img, (AABB){V2(-bs, -bs), AddV2(img_size(img), V2(bs, bs))}, WHITE, .layer=LAYER_UI});
+}
+
+void debug_draw_shadow_info(Vec3 frustum_tip, Vec3 cam_forward, Vec3 cam_right, Mat4 light_space_matrix) {
+		debug_draw_img(state.shadows.color_img, 0);
+		FrustumVertices fv = get_frustum_vertices(frustum_tip, cam_forward, cam_right);
+
+		Vec2 projs[5];
+		for (int i = 0; i < 5; ++i) {
+			Vec3 v = fv.vertices[i];
+			Vec4 p = V4(v.x, v.y, v.z, 1.0);
+			Vec4 proj = MulM4V4(light_space_matrix, p);
+			proj.x /= proj.w;
+			proj.y /= proj.w;
+			proj.z /= proj.w;
+
+			proj.x *= 0.5f;
+			proj.x += 0.5f;
+			proj.y *= 0.5f;
+			proj.y += 0.5f;
+			proj.z *= 0.5f;
+			proj.z += 0.5f;
+
+			proj.x *= 512.0f;
+			proj.y *= 512.0f;
+
+			projs[i] = proj.XY;
+			dbgsquare(proj.XY);
+		}
+
+		dbgline(projs[0], projs[1]);
+		dbgline(projs[0], projs[2]);
+		dbgline(projs[0], projs[3]);
+		dbgline(projs[0], projs[4]);
+		dbgline(projs[1], projs[2]);
+		dbgline(projs[2], projs[3]);
+		dbgline(projs[3], projs[4]);
+		dbgline(projs[4], projs[1]);
+}
+
+
 void actually_draw_thing(DrawnThing *it, Mat4 light_space_matrix, bool for_outline)
 {
 	if(it->mesh)
@@ -5170,7 +5235,7 @@ void actually_draw_thing(DrawnThing *it, Mat4 light_space_matrix, bool for_outli
 // I moved this out into its own separate function so that you could
 // define helper functions to be used multiple times in it, and those functions
 // would be near the actual 3d drawing in the file
-void flush_all_drawn_things(Vec3 light_dir)
+void flush_all_drawn_things(Vec3 light_dir, Vec3 cam_pos, Vec3 cam_facing, Vec3 cam_right)
 {
 	// Draw all the 3D drawn things. Draw the shadows, then draw the things with the shadows.
 	// Process armatures and upload their skeleton textures
@@ -5254,10 +5319,12 @@ void flush_all_drawn_things(Vec3 light_dir)
 		// do the shadow pass
 		Mat4 light_space_matrix;
 		{
-			Shadow_Volume_Params svp = calculate_shadow_volume_params(light_dir);
+			Shadow_Volume_Params svp = calculate_shadow_volume_params(light_dir, cam_pos, cam_facing, cam_right);
+
 			Mat4 shadow_view       = LookAt_RH(V3(0, 0, 0), light_dir, V3(0, 1, 0));
 			Mat4 shadow_projection = Orthographic_RH_NO(svp.l, svp.r, svp.b, svp.t, svp.n, svp.f);
 			light_space_matrix = MulM4(shadow_projection, shadow_view);
+			// debug_draw_shadow_info(cam_pos, cam_facing, cam_right, light_space_matrix);
 
 			sg_begin_pass(state.shadows.pass, &state.shadows.pass_action);
 
@@ -5552,7 +5619,7 @@ void frame(void)
 		}
 
 
-		flush_all_drawn_things(light_dir);
+		flush_all_drawn_things(light_dir, cam_pos, facing, right);
 
 		// draw the freaking outline. Play ball!
 		draw_quad((DrawParams){quad_at(V2(0.0, screen_size().y), screen_size()), IMG(state.outline_pass_image), WHITE, .layer = LAYER_UI_FG, .custom_pipeline = state.twodee_outline_pip});

threedee.glsl

@@ -147,7 +147,7 @@ float do_shadow_sample(sampler2D shadowMap, vec2 uv, float scene_depth, float n_
 
 	float offset_scale_N = sqrt(1 - n_dot_l*n_dot_l);
 	float offset_scale_L = offset_scale_N / n_dot_l;
-	float bias = 0.0002 * offset_scale_N + 0.0001 * offset_scale_L;
+	float bias = 0.0004 * offset_scale_N + 0.0001 * offset_scale_L;
 
 	map_depth += bias;
 

tuning.h

@@ -60,5 +60,5 @@
 //Rendering
 #define FIELD_OF_VIEW (PI32/4.0f)
 #define NEAR_PLANE_DISTANCE (0.01f)
-#define FAR_PLANE_DISTANCE (1000.0f)
+#define FAR_PLANE_DISTANCE (45.0f)
 #define SHADOW_MAP_DIMENSION (2048)