From 7a40b0bff2dd8b97f62e6f6901a3d1ce94d98d01 Mon Sep 17 00:00:00 2001
From: jacob <jacob@cagori.com>
Date: Tue, 16 Dec 2025 15:11:36 -0600
Subject: [PATCH] backdrop shader

---
 src/base/base_async.c            |  1 +
 src/pp/pp_vis/pp_vis_core.c      |  9 +++++--
 src/pp/pp_vis/pp_vis_shaders.cgh |  5 ++++
 src/pp/pp_vis/pp_vis_shaders.g   | 44 ++++++++++++++++++++++++++++++++
 src/pp/pp_vis/pp_vis_widgets.c   |  1 +
 5 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/src/base/base_async.c b/src/base/base_async.c
index da83d3e5..61e90108 100644
--- a/src/base/base_async.c
+++ b/src/base/base_async.c
@@ -91,6 +91,7 @@ void AsyncWorkerEntryPoint(WaveLaneCtx *lane)
         //- End tick
 
         WaveSync(lane);
+
         ResetArena(tick.arena);
         {
             Arena *tick_arena = tick.arena;
diff --git a/src/pp/pp_vis/pp_vis_core.c b/src/pp/pp_vis/pp_vis_core.c
index 9d8587c3..cb5d86d5 100644
--- a/src/pp/pp_vis/pp_vis_core.c
+++ b/src/pp/pp_vis/pp_vis_core.c
@@ -147,7 +147,7 @@ void V_TickForever(WaveLaneCtx *lane)
         //////////////////////////////
         //- Spawn test ents
 
-        if (V.world->tick == 1)
+        if (frame->tick == 1)
         {
             S_Key child_key = S_RandKey();
             S_Key camera_key = S_RandKey();
@@ -615,8 +615,13 @@ void V_TickForever(WaveLaneCtx *lane)
                 params.target_ro = draw_target_ro;
                 params.target_rw = draw_target_rw;
                 params.shape_verts = dverts_ro;
-                params.world_to_draw_xf = world_to_draw_xf;
                 params.target_cursor_pos = draw_cursor;
+
+                params.background_color_a = LinearFromSrgb(VEC4(0.30, 0.30, 0.30, 1));
+                params.background_color_b = LinearFromSrgb(VEC4(0.15, 0.15, 0.15, 1));
+
+                params.world_to_draw_xf = world_to_draw_xf;
+                params.draw_to_world_xf = draw_to_world_xf;
             }
             G_ResourceHandle params_buff = G_PushBufferFromString(frame->gpu_arena, frame->cl, StringFromStruct(&params));
             G_StructuredBufferRef params_ro = G_PushStructuredBufferRef(frame->gpu_arena, params_buff, V_DParams);
diff --git a/src/pp/pp_vis/pp_vis_shaders.cgh b/src/pp/pp_vis/pp_vis_shaders.cgh
index cb322685..8a4af443 100644
--- a/src/pp/pp_vis/pp_vis_shaders.cgh
+++ b/src/pp/pp_vis/pp_vis_shaders.cgh
@@ -13,7 +13,12 @@ Struct(V_DParams)
     G_StructuredBufferRef shape_verts;
 
     Vec2 target_cursor_pos;
+
+    Vec4 background_color_a;
+    Vec4 background_color_b;
+
     Xform world_to_draw_xf;
+    Xform draw_to_world_xf;
 };
 
 ////////////////////////////////////////////////////////////
diff --git a/src/pp/pp_vis/pp_vis_shaders.g b/src/pp/pp_vis/pp_vis_shaders.g
index 605ce78d..70a5cacc 100644
--- a/src/pp/pp_vis/pp_vis_shaders.g
+++ b/src/pp/pp_vis/pp_vis_shaders.g
@@ -12,6 +12,50 @@ ComputeShader2D(V_BackdropCS, 8, 8)
     {
         Vec4 result = Vec4(0.05, 0.05, 0.05, 1);
 
+        /* Checkered square color */
+        {
+            i32 color_idx = 0;
+            Vec4 colors[2] = {
+                params.background_color_a,
+                params.background_color_b
+            };
+            Vec2 world_pos = mul(params.draw_to_world_xf, Vec3(target_pos, 1));
+            Vec2 world_pos_modded = fmod(abs(world_pos), Vec2(2, 2));
+            if (world_pos_modded.x < 1)
+            {
+                color_idx = !color_idx;
+            }
+            if (world_pos_modded.y < 1)
+            {
+                color_idx = !color_idx;
+            }
+            if (world_pos.x < 0)
+            {
+                color_idx = !color_idx;
+            }
+            if (world_pos.y < 0)
+            {
+                color_idx = !color_idx;
+            }
+            result = colors[color_idx];
+        }
+
+        /* Axis color */
+        {
+            f32 thickness = 2;
+            Vec2 zero_screen = mul(params.world_to_draw_xf, Vec3(0, 0, 1));
+            f32 x_dist = abs(target_pos.x - zero_screen.x);
+            f32 y_dist = abs(target_pos.y - zero_screen.y);
+            if (y_dist <= (thickness * 0.5))
+            {
+                result = Color_Red;
+            }
+            else if (x_dist <= (thickness * 0.5))
+            {
+                result = Color_Green;
+            }
+        }
+
         target[target_pos] = result;
     }
 }
diff --git a/src/pp/pp_vis/pp_vis_widgets.c b/src/pp/pp_vis/pp_vis_widgets.c
index 567cf8fe..6d0fdb89 100644
--- a/src/pp/pp_vis/pp_vis_widgets.c
+++ b/src/pp/pp_vis/pp_vis_widgets.c
@@ -54,6 +54,7 @@ String V_StringFromHotkey(Arena *arena, V_Hotkey hotkey)
         PushStringToList(scratch.arena, &parts, Lit("Shift"));
     }
     PushStringToList(scratch.arena, &parts, StringFromButton(hotkey.button));
+    EndScratch(scratch);
     return StringFromList(arena, parts, Lit(" + "));
 }