Add dithering for gradients

src/renderer/renderer_dx12.cpp

@@ -148,6 +148,10 @@ float4 PSMain(PSInput input) : SV_TARGET {
         }
     }
 
+    // Dither to reduce gradient banding (interleaved gradient noise)
+    float dither = frac(52.9829189 * frac(dot(input.pos.xy, float2(0.06711056, 0.00583715)))) - 0.5;
+    col.rgb += dither / 255.0;
+
     if (col.a < 0.002) discard;
     return col;
 }

src/renderer/renderer_metal.mm

@@ -133,6 +133,10 @@ fragment float4 fragment_main(Fragment in [[stage_in]],
         }
     }
 
+    // Dither to reduce gradient banding (interleaved gradient noise)
+    float dither = fract(52.9829189 * fract(dot(in.pos.xy, float2(0.06711056, 0.00583715)))) - 0.5;
+    col.rgb += dither / 255.0;
+
     if (col.a < 0.002) discard_fragment();
     return col;
 }

src/ui/ui_widgets.cpp

@@ -268,7 +268,7 @@ B32 ui_button(const char *id, const char *text) {
     CLAY(eid,
         .layout = {
             .sizing = { .width = CLAY_SIZING_FIT(), .height = CLAY_SIZING_FIXED(WIDGET_BUTTON_HEIGHT) },
-            .padding = { uip(12), uip(12), 0, 0 },
+            .padding = { uip(12), uip(12), uip(1), 0 },
             .childAlignment = { .y = CLAY_ALIGN_Y_CENTER },
         },
         .backgroundColor = base,
@@ -1099,7 +1099,7 @@ S32 ui_modal(const char *id, const char *title, const char *message,
                 CLAY(btn_id,
                     .layout = {
                         .sizing = { .width = CLAY_SIZING_FIT(), .height = CLAY_SIZING_FIXED(WIDGET_BUTTON_HEIGHT) },
-                        .padding = { uip(16), uip(16), 0, 0 },
+                        .padding = { uip(16), uip(16), uip(1), 0 },
                         .childAlignment = { .y = CLAY_ALIGN_Y_CENTER },
                     },
                     .backgroundColor = mbtn_base,