offscreen light falloff

res/sh/sh_common.h

@@ -151,7 +151,7 @@ SH_ASSERT_ROOT_CONST(struct sh_flood_constants, 8);  /* Expected to match num32B
  * ========================== */
 
 #define SH_SHADE_FLAG_NONE              (0 << 0)
-#define SH_SHADE_FLAG_LIGHTING_ENABLED  (1 << 0)
+#define SH_SHADE_FLAG_DISABLE_EFFECTS   (1 << 0)
 
 SH_STRUCT(sh_shade_constants {
     /* ---------------------------------------------------- */

res/sh/shade.hlsl

@@ -27,7 +27,7 @@ struct cs_input {
 
 #define SAMPLES 16
 #define MARCHES 16
-#define AMBIENT float3(0, 0, 0)
+#define EDGE_FALLOFF 100
 
 float rand_angle(uint2 pos, uint ray_index) {
     Texture3D<uint> noise_tex = g_noise_textures[SH_BLUE_NOISE_TEX_ID];
@@ -46,7 +46,7 @@ INLINE float3 get_light_in_dir(uint2 ray_start, float2 ray_dir)
     Texture2D<uint2> flood_tex = g_textures_uint2[g_constants.emittance_flood_tex_urid];
     Texture2D<float4> emittance_tex = g_textures_float4[g_constants.emittance_tex_urid];
 
-    float3 result = AMBIENT;
+    float3 result = float3(0, 0, 0);
     float2 at_float = ray_start;
     uint2 at_uint = ray_start;
     for (uint i = 0; i < MARCHES; ++i) {
@@ -54,13 +54,17 @@ INLINE float3 get_light_in_dir(uint2 ray_start, float2 ray_dir)
         float2 dist_vec = at_float - (float2)flood;
         float dist = length(dist_vec);
         if (dist < 1) {
-            result = emittance_tex[flood].rgb;
+            /* Scale light by distance from edge so that offscreen-lights fade in/out rather than popping in */
+            float dist_x = min(abs(g_constants.tex_width - at_float.x), at_float.x);
+            float dist_y = min(abs(g_constants.tex_height - at_float.y), at_float.y);
+            float dist_scale = min(min(dist_x, dist_y) / EDGE_FALLOFF, 1);
+            result = emittance_tex[flood].rgb * dist_scale;
             break;
         } else {
             at_float += ray_dir * dist;
             at_uint = round(at_float);
             if (at_uint.x < 0 || at_uint.x >= g_constants.tex_width || at_uint.y < 0 || at_uint.y >= g_constants.tex_height) {
-                /* Ambient lighting (ray hit edge of screen) */
+                /* Ray hit edge of screen */
                 break;
             }
         }
@@ -100,7 +104,7 @@ SH_ENTRY(ROOTSIG) void cs(struct cs_input input)
         color *= albedo_tex[id];
 
         /* Apply lighting */
-        if (g_constants.flags & SH_SHADE_FLAG_LIGHTING_ENABLED) {
+        if (!(g_constants.flags & SH_SHADE_FLAG_DISABLE_EFFECTS)) {
             color.rgb *= get_light_at_pos(id);
         }
 

src/config.h

@@ -23,15 +23,15 @@
 #define RESOURCES_EMBEDDED (!DEVELOPER)
 #define RESOURCE_RELOADING (DEVELOPER && !RESOURCES_EMBEDDED)
 
-#define DEFAULT_CAMERA_WIDTH (10.0)
+#define DEFAULT_CAMERA_WIDTH (16)
 #define DEFAULT_CAMERA_HEIGHT (DEFAULT_CAMERA_WIDTH / (16.0 / 9.0))
 
 /* Rendered image size will be (camera_width * pixels_per_unit) x (camera_height * pixels_per_unit) */
-#define PIXELS_PER_UNIT 64.0
+#define PIXELS_PER_UNIT 40.0
 
-/* Rendered texture size + extra room for off-screen lights */
+/* Rendered texture size + extra room for off-screen light falloff */
-#define RENDER_WIDTH    (640 + 512)
+#define RENDER_WIDTH    (640 + 200)
-#define RENDER_HEIGHT   (360 + 512)
+#define RENDER_HEIGHT   (360 + 200)
 
 /* How many ticks back in time should the user thread blend between?
  * <Delay> = <USER_INTERP_RATIO> * <Tick interval>

src/gp.h

@@ -108,7 +108,7 @@ struct gp_render_params {
     struct v2i32 render_size;
     struct xform world_to_render_xf;
     struct xform render_to_ui_xf;
-    b32 lighting_enabled;
+    b32 effects_disabled;
 };
 
 struct gp_render_sig *gp_render_sig_alloc(void);

src/gp_dx12.c

@@ -3194,7 +3194,7 @@ struct gp_resource *gp_run_render(struct gp_render_sig *render_sig, struct gp_re
         }
 
         /* Flood pass */
-        if (flood_pipeline->success && params.lighting_enabled) {
+        if (flood_pipeline->success && !params.effects_disabled) {
             __profn("Flood pass");
             __profnc_dx12(cl->cq->prof, cl->cl, "Flood pass", RGB32_F(0.5, 0.2, 0.2));
 
@@ -3288,8 +3288,8 @@ struct gp_resource *gp_run_render(struct gp_render_sig *render_sig, struct gp_re
             ID3D12GraphicsCommandList_SetComputeRootSignature(cl->cl, shade_pipeline->rootsig);
 
             u32 shade_flags = SH_SHADE_FLAG_NONE;
-            if (params.lighting_enabled) {
+            if (params.effects_disabled) {
-                shade_flags |= SH_SHADE_FLAG_LIGHTING_ENABLED;
+                shade_flags |= SH_SHADE_FLAG_DISABLE_EFFECTS;
             }
 
             /* Set constants */

src/sim_step.c

@@ -269,7 +269,7 @@ INTERNAL void test_spawn_entities2(struct sim_ent *parent, struct v2 pos)
         struct sim_ent *e = sim_ent_alloc_sync_src(parent);
 
         f32 rot = 0;
-        struct v2 size = V2(0.1, 0.1);
+        struct v2 size = V2(0.125, 0.125);
         struct xform xf = XFORM_TRS(.t = pos, .r = rot, .s = size);
         sim_ent_set_xform(e, xf);
 

src/user.c

@@ -986,12 +986,12 @@ INTERNAL void user_update(struct sys_window *window)
      * Update world to render xform from world to ui xform
      * ========================== */
 
-    b32 lighting_enabled = 1;
+    b32 effects_disabled = 0;
     G.render_size = V2(RENDER_WIDTH, RENDER_HEIGHT);
 
     if (G.debug_camera) {
         G.render_size = G.ui_size;
-        lighting_enabled = 0;
+        effects_disabled = 1;
         G.world_to_render_xf = G.world_to_ui_xf;
     } else {
         struct xform ui_to_world_xf = xform_invert(G.world_to_ui_xf);
@@ -2078,7 +2078,7 @@ INTERNAL void user_update(struct sys_window *window)
             params.render_size = world_resolution;
             params.world_to_render_xf = G.world_to_render_xf;
             params.render_to_ui_xf = G.render_to_ui_xf;
-            params.lighting_enabled = lighting_enabled;
+            params.effects_disabled = effects_disabled;
             render_texture = gp_run_render(G.render_sig, params);
         }