From b097857f93f3d693000301be9b2d9cd26d3c3346 Mon Sep 17 00:00:00 2001
From: Neko Ayaka <neko@ayaka.moe>
Date: Thu, 23 Oct 2025 15:36:52 +0800
Subject: [PATCH] feat(stage-tamagotchi): bring back fade on hover

Co-authored-by: Ilya Bogdanov <34226834+skirkru@users.noreply.github.com>
---
 .../src/renderer/pages/index.vue              | 89 ++++++++++---------
 .../src/renderer/stores/window-controls.ts    |  2 +-
 .../stage-ui/src/composables/canvas-alpha.ts  | 80 +++++++++++++++++
 packages/stage-ui/src/composables/index.ts    |  1 +
 4 files changed, 131 insertions(+), 41 deletions(-)
 create mode 100644 packages/stage-ui/src/composables/canvas-alpha.ts

diff --git a/apps/stage-tamagotchi/src/renderer/pages/index.vue b/apps/stage-tamagotchi/src/renderer/pages/index.vue
index 9e209af35..632c8ce26 100644
--- a/apps/stage-tamagotchi/src/renderer/pages/index.vue
+++ b/apps/stage-tamagotchi/src/renderer/pages/index.vue
@@ -1,34 +1,31 @@
 <script setup lang="ts">
 import { WidgetStage } from '@proj-airi/stage-ui/components/scenes'
+import { useCanvasPixelIsTransparentAtPoint } from '@proj-airi/stage-ui/composables/canvas-alpha'
 import { useLive2d } from '@proj-airi/stage-ui/stores/live2d'
 import { storeToRefs } from 'pinia'
-import { computed, ref, watch } from 'vue'
+import { computed, ref, toRef, watch } from 'vue'
 
 import ControlsIsland from '../components/Widgets/ControlsIsland/index.vue'
 import ResourceStatusIsland from '../components/Widgets/ResourceStatusIsland/index.vue'
 
-import { useWindowStore } from '../stores/window'
+import { useElectronRelativeMouse, useWindowStore } from '../stores/window'
 import { useWindowControlStore } from '../stores/window-controls'
 import { WindowControlMode } from '../types/window-controls'
 
-export interface Point {
-  x: number
-  y: number
-}
-
-const windowControlStore = useWindowControlStore()
-const { scale, positionInPercentageString } = storeToRefs(useLive2d())
-
-const { live2dLookAtX, live2dLookAtY } = storeToRefs(useWindowStore())
-const widgetStageRef = ref<{ canvasElement: () => HTMLCanvasElement }>()
 const resourceStatusIslandRef = ref<InstanceType<typeof ResourceStatusIsland>>()
-
+const widgetStageRef = ref<{ canvasElement: () => HTMLCanvasElement }>()
+const stageCanvas = toRef(() => widgetStageRef.value?.canvasElement())
 const isClickThrough = ref(false)
-const isFirstTime = ref(true)
+const isPassingThrough = ref(false)
 const isLoading = ref(true)
 const componentStateStage = ref<'pending' | 'loading' | 'mounted'>('pending')
 
-watch(componentStateStage, () => isLoading.value = componentStateStage.value !== 'mounted', { immediate: true })
+const windowControlStore = useWindowControlStore()
+const { x: relativeMouseX, y: relativeMouseY } = useElectronRelativeMouse()
+const isTransparent = useCanvasPixelIsTransparentAtPoint(stageCanvas, relativeMouseX, relativeMouseY)
+
+const { scale, positionInPercentageString } = storeToRefs(useLive2d())
+const { live2dLookAtX, live2dLookAtY } = storeToRefs(useWindowStore())
 
 const modeIndicatorClass = computed(() => {
   switch (windowControlStore.controlMode) {
@@ -42,33 +39,53 @@ const modeIndicatorClass = computed(() => {
       return ''
   }
 })
+
+watch(componentStateStage, () => isLoading.value = componentStateStage.value !== 'mounted', { immediate: true })
+watch(isTransparent, (transparent) => {
+  isClickThrough.value = transparent
+  isPassingThrough.value = transparent
+  windowControlStore.isIgnoringMouseEvent = !transparent
+})
 </script>
 
 <template>
   <div
-    :class="[modeIndicatorClass, {
-      'op-0': windowControlStore.isIgnoringMouseEvent && !isClickThrough && !isFirstTime,
-    }]"
+    :class="[modeIndicatorClass]"
     max-h="[100vh]"
     max-w="[100vw]"
     flex="~ col"
     relative z-2 h-full overflow-hidden rounded-xl
     transition="opacity duration-500 ease-in-out"
   >
-    <div v-show="!isLoading" relative h-full w-full items-end gap-2 class="view">
-      <ResourceStatusIsland ref="resourceStatusIslandRef" />
-      <WidgetStage
-        ref="widgetStageRef"
-        v-model:state="componentStateStage"
-        h-full w-full
-        flex-1
-        :focus-at="{ x: live2dLookAtX, y: live2dLookAtY }"
-        :scale="scale"
-        :x-offset="positionInPercentageString.x"
-        :y-offset="positionInPercentageString.y"
-        mb="<md:18"
-      />
-      <ControlsIsland />
+    <div
+      v-show="!isLoading"
+      :class="[
+        'relative h-full w-full items-end gap-2',
+        'transition-opacity duration-250 ease-in-out',
+      ]"
+    >
+      <div
+        :class="[
+          windowControlStore.isIgnoringMouseEvent && !isClickThrough ? 'op-0' : 'op-100',
+          'absolute',
+          'top-0 left-0 w-full h-full',
+          'transition-opacity duration-250 ease-in-out',
+        ]"
+      >
+        <ResourceStatusIsland ref="resourceStatusIslandRef" />
+        <WidgetStage
+          ref="widgetStageRef"
+          v-model:state="componentStateStage"
+          h-full w-full
+          flex-1
+          :focus-at="{ x: live2dLookAtX, y: live2dLookAtY }"
+          :scale="scale"
+          :x-offset="positionInPercentageString.x"
+          :y-offset="positionInPercentageString.y"
+          mb="<md:18"
+        />
+        <ControlsIsland />
+      </div>
     </div>
     <div v-show="isLoading" h-full w-full>
       <div class="absolute left-0 top-0 z-99 h-full w-full flex cursor-grab items-center justify-center overflow-hidden">
@@ -138,14 +155,6 @@ const modeIndicatorClass = computed(() => {
 </template>
 
 <style scoped>
-.view {
-  transition: opacity 0.5s ease-in-out;
-
-  .show-on-hover {
-    opacity: 1;
-  }
-}
-
 @keyframes wall-move {
   0% {
     transform: translateX(calc(var(--wall-width) * -2));
diff --git a/apps/stage-tamagotchi/src/renderer/stores/window-controls.ts b/apps/stage-tamagotchi/src/renderer/stores/window-controls.ts
index 650be228e..f4b98a7c4 100644
--- a/apps/stage-tamagotchi/src/renderer/stores/window-controls.ts
+++ b/apps/stage-tamagotchi/src/renderer/stores/window-controls.ts
@@ -11,7 +11,7 @@ import { startClickThrough, stopClickThrough } from '../utils/windows'
 export const useWindowControlStore = defineStore('windowControl', () => {
   const controlMode = ref<WindowControlMode>(WindowControlMode.NONE)
   const isControlActive = ref(false)
-  const isIgnoringMouseEvent = ref(true)
+  const isIgnoringMouseEvent = ref(false)
 
   function toggleMode(mode: WindowControlMode) {
     controlMode.value = mode
diff --git a/packages/stage-ui/src/composables/canvas-alpha.ts b/packages/stage-ui/src/composables/canvas-alpha.ts
new file mode 100644
index 000000000..03b34afcc
--- /dev/null
+++ b/packages/stage-ui/src/composables/canvas-alpha.ts
@@ -0,0 +1,80 @@
+import type { MaybeRefOrGetter } from '@vueuse/core'
+import type { Ref } from 'vue'
+
+import { toRef, unrefElement, useElementBounding } from '@vueuse/core'
+import { computed } from 'vue'
+
+export function useCanvasPixelAtPoint(
+  canvas: MaybeRefOrGetter<HTMLCanvasElement | undefined>,
+  pointX: MaybeRefOrGetter<number>,
+  pointY: MaybeRefOrGetter<number>,
+): {
+  inCanvas: Ref<boolean>
+  pixel: Ref<Uint8Array | number[]>
+} {
+  const canvasRef = toRef(canvas)
+
+  const { left, top, width, height } = useElementBounding(canvasRef)
+  const xRef = toRef(pointX)
+  const yRef = toRef(pointY)
+
+  const inCanvas = computed(() => {
+    if (canvasRef.value == null) {
+      return false
+    }
+
+    const xIn = xRef.value - left.value
+    const yIn = yRef.value - top.value
+    return xIn >= 0 && yIn >= 0 && xIn < width.value && yIn < height.value
+  })
+
+  const pixel = computed(() => {
+    const el = unrefElement(canvasRef)
+    if (!el || !inCanvas.value)
+      return new Uint8Array([0, 0, 0, 0])
+
+    const gl = (el.getContext('webgl2') || el.getContext('webgl')) as WebGL2RenderingContext | WebGLRenderingContext | null
+    if (!gl)
+      return new Uint8Array([0, 0, 0, 0])
+
+    const xIn = xRef.value - left.value
+    const yIn = yRef.value - top.value
+
+    const scaleX = gl.drawingBufferWidth / width.value
+    const scaleY = gl.drawingBufferHeight / height.value
+    const pixelX = Math.floor(xIn * scaleX)
+    // Flip Y; subtract 1 to avoid top-edge off-by-one
+    const pixelY = Math.floor(gl.drawingBufferHeight - 1 - yIn * scaleY)
+
+    const data = new Uint8Array(4)
+    try {
+      gl.readPixels(pixelX, pixelY, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, data)
+    }
+    catch {
+      return new Uint8Array([0, 0, 0, 0])
+    }
+    return data
+  })
+
+  return {
+    inCanvas,
+    pixel,
+  }
+}
+
+export function useCanvasPixelIsTransparent(
+  pixel: Ref<Uint8Array | number[]>,
+  threshold = 10,
+): Ref<boolean> {
+  return computed(() => pixel.value[3] < threshold)
+}
+
+export function useCanvasPixelIsTransparentAtPoint(
+  canvas: MaybeRefOrGetter<HTMLCanvasElement | undefined>,
+  pointX: MaybeRefOrGetter<number>,
+  pointY: MaybeRefOrGetter<number>,
+  threshold = 10,
+): Ref<boolean> {
+  const { pixel } = useCanvasPixelAtPoint(canvas, pointX, pointY)
+  return useCanvasPixelIsTransparent(pixel, threshold)
+}
diff --git a/packages/stage-ui/src/composables/index.ts b/packages/stage-ui/src/composables/index.ts
index 3ddd3e77c..6ce994ecd 100644
--- a/packages/stage-ui/src/composables/index.ts
+++ b/packages/stage-ui/src/composables/index.ts
@@ -1,4 +1,5 @@
 export * from './audio'
+export * from './canvas-alpha'
 export * from './llmmarkerParser'
 export * from './markdown'
 export * from './micvad'