feat: add overlay, soft light, hard light, difference, exclusion blend modes to composite

Integer-math implementations with pre-allocated scratch buffers.
IconSelect picker updated with 10 blend modes. i18n for en/ru/zh.

TODO-css-improvements.md

@@ -70,7 +70,7 @@ Need to research HAOS communication options first (WebSocket API, REST API, MQTT
 ### `composite`
 
 - [ ] Allow nested composites (with cycle detection)
-- [ ] More blend modes: overlay, soft light, hard light, difference, exclusion
+- [x] More blend modes: overlay, soft light, hard light, difference, exclusion
 - [x] Per-layer LED range masks (optional start/end/reverse on each composite layer)
 
 ### `notification`

server/src/wled_controller/core/processing/composite_stream.py

@@ -17,6 +17,11 @@ _BLEND_ADD = "add"
 _BLEND_MULTIPLY = "multiply"
 _BLEND_SCREEN = "screen"
 _BLEND_OVERRIDE = "override"
+_BLEND_OVERLAY = "overlay"
+_BLEND_SOFT_LIGHT = "soft_light"
+_BLEND_HARD_LIGHT = "hard_light"
+_BLEND_DIFFERENCE = "difference"
+_BLEND_EXCLUSION = "exclusion"
 
 
 class CompositeColorStripStream(ColorStripStream):
@@ -348,12 +353,125 @@ class CompositeColorStripStream(ColorStripStream):
         u16a >>= 8
         np.copyto(out, u16a, casting="unsafe")
 
+    def _blend_overlay(self, bottom: np.ndarray, top: np.ndarray, alpha: int,
+                       out: np.ndarray) -> None:
+        """Overlay blend: multiply darks, screen lights, then lerp with alpha.
+
+        if bottom < 128: blended = 2*bottom*top >> 8
+        else:            blended = 255 - 2*(255-bottom)*(255-top) >> 8
+        """
+        u16a, u16b = self._u16_a, self._u16_b
+        np.copyto(u16a, bottom, casting="unsafe")
+        np.copyto(u16b, top, casting="unsafe")
+        # Multiply path: 2*b*t >> 8
+        mul = (u16a * u16b) >> 7  # * 2 >> 8 == >> 7
+        # Screen path: 255 - 2*(255-b)*(255-t) >> 8
+        scr = 255 - (((255 - u16a) * (255 - u16b)) >> 7)
+        # Select based on bottom < 128
+        mask = u16a < 128
+        blended = np.where(mask, mul, scr)
+        np.clip(blended, 0, 255, out=blended)
+        # Lerp: result = (bottom * (256-a) + blended * a) >> 8
+        np.copyto(u16a, bottom, casting="unsafe")
+        u16a *= (256 - alpha)
+        blended *= alpha
+        u16a += blended
+        u16a >>= 8
+        np.copyto(out, u16a, casting="unsafe")
+
+    def _blend_soft_light(self, bottom: np.ndarray, top: np.ndarray, alpha: int,
+                          out: np.ndarray) -> None:
+        """Soft light blend (Pegtop formula), then lerp with alpha.
+
+        blended = (1 - 2*t/255) * b*b/255 + 2*t*b/255
+        """
+        u16a, u16b = self._u16_a, self._u16_b
+        np.copyto(u16a, bottom, casting="unsafe")
+        np.copyto(u16b, top, casting="unsafe")
+        # term1 = (255 - 2*t) * b * b / (255*255)
+        # term2 = 2 * t * b / 255
+        # Use intermediate 32-bit to avoid overflow
+        b32 = u16a.astype(np.uint32)
+        t32 = u16b.astype(np.uint32)
+        blended = ((255 - 2 * t32) * b32 * b32 + 2 * t32 * b32 * 255) // (255 * 255)
+        np.clip(blended, 0, 255, out=blended)
+        # Lerp
+        np.copyto(u16a, bottom, casting="unsafe")
+        u16a *= (256 - alpha)
+        blended_u16 = blended.astype(np.uint16)
+        blended_u16 *= alpha
+        u16a += blended_u16
+        u16a >>= 8
+        np.copyto(out, u16a, casting="unsafe")
+
+    def _blend_hard_light(self, bottom: np.ndarray, top: np.ndarray, alpha: int,
+                          out: np.ndarray) -> None:
+        """Hard light blend: overlay with top/bottom roles swapped.
+
+        if top < 128: blended = 2*bottom*top >> 8
+        else:         blended = 255 - 2*(255-bottom)*(255-top) >> 8
+        """
+        u16a, u16b = self._u16_a, self._u16_b
+        np.copyto(u16a, bottom, casting="unsafe")
+        np.copyto(u16b, top, casting="unsafe")
+        mul = (u16a * u16b) >> 7
+        scr = 255 - (((255 - u16a) * (255 - u16b)) >> 7)
+        # Select based on top < 128 (differs from overlay)
+        mask = u16b < 128
+        blended = np.where(mask, mul, scr)
+        np.clip(blended, 0, 255, out=blended)
+        # Lerp
+        np.copyto(u16a, bottom, casting="unsafe")
+        u16a *= (256 - alpha)
+        blended *= alpha
+        u16a += blended
+        u16a >>= 8
+        np.copyto(out, u16a, casting="unsafe")
+
+    def _blend_difference(self, bottom: np.ndarray, top: np.ndarray, alpha: int,
+                          out: np.ndarray) -> None:
+        """Difference blend: |bottom - top|, then lerp with alpha."""
+        u16a, u16b = self._u16_a, self._u16_b
+        np.copyto(u16a, bottom, casting="unsafe")
+        np.copyto(u16b, top, casting="unsafe")
+        # abs diff using signed subtraction
+        blended = np.abs(u16a.astype(np.int16) - u16b.astype(np.int16)).astype(np.uint16)
+        # Lerp
+        np.copyto(u16a, bottom, casting="unsafe")
+        u16a *= (256 - alpha)
+        blended *= alpha
+        u16a += blended
+        u16a >>= 8
+        np.copyto(out, u16a, casting="unsafe")
+
+    def _blend_exclusion(self, bottom: np.ndarray, top: np.ndarray, alpha: int,
+                         out: np.ndarray) -> None:
+        """Exclusion blend: bottom + top - 2*bottom*top/255, then lerp with alpha."""
+        u16a, u16b = self._u16_a, self._u16_b
+        np.copyto(u16a, bottom, casting="unsafe")
+        np.copyto(u16b, top, casting="unsafe")
+        # blended = b + t - 2*b*t/255
+        blended = u16a + u16b - ((u16a * u16b) >> 7)
+        np.clip(blended, 0, 255, out=blended)
+        # Lerp
+        np.copyto(u16a, bottom, casting="unsafe")
+        u16a *= (256 - alpha)
+        blended *= alpha
+        u16a += blended
+        u16a >>= 8
+        np.copyto(out, u16a, casting="unsafe")
+
     _BLEND_DISPATCH = {
         _BLEND_NORMAL: "_blend_normal",
         _BLEND_ADD: "_blend_add",
         _BLEND_MULTIPLY: "_blend_multiply",
         _BLEND_SCREEN: "_blend_screen",
         _BLEND_OVERRIDE: "_blend_override",
+        _BLEND_OVERLAY: "_blend_overlay",
+        _BLEND_SOFT_LIGHT: "_blend_soft_light",
+        _BLEND_HARD_LIGHT: "_blend_hard_light",
+        _BLEND_DIFFERENCE: "_blend_difference",
+        _BLEND_EXCLUSION: "_blend_exclusion",
     }
 
     # ── Processing loop ─────────────────────────────────────────

server/src/wled_controller/static/js/features/color-strips-composite.ts

@@ -53,9 +53,14 @@ function _getCompositeBlendItems() {
     return [
         { value: 'normal',     icon: _icon(P.square),      label: t('color_strip.composite.blend_mode.normal'),     desc: t('color_strip.composite.blend_mode.normal.desc') },
         { value: 'add',        icon: _icon(P.sun),          label: t('color_strip.composite.blend_mode.add'),        desc: t('color_strip.composite.blend_mode.add.desc') },
-        { value: 'multiply', icon: _icon(P.eye),      label: t('color_strip.composite.blend_mode.multiply'), desc: t('color_strip.composite.blend_mode.multiply.desc') },
+        { value: 'multiply',   icon: _icon(P.moon),         label: t('color_strip.composite.blend_mode.multiply'),   desc: t('color_strip.composite.blend_mode.multiply.desc') },
         { value: 'screen',     icon: _icon(P.monitor),      label: t('color_strip.composite.blend_mode.screen'),     desc: t('color_strip.composite.blend_mode.screen.desc') },
-        { value: 'override', icon: _icon(P.zap),      label: t('color_strip.composite.blend_mode.override'), desc: t('color_strip.composite.blend_mode.override.desc') },
+        { value: 'overlay',    icon: _icon(P.copy),          label: t('color_strip.composite.blend_mode.overlay'),    desc: t('color_strip.composite.blend_mode.overlay.desc') },
+        { value: 'soft_light', icon: _icon(P.sunDim),       label: t('color_strip.composite.blend_mode.soft_light'), desc: t('color_strip.composite.blend_mode.soft_light.desc') },
+        { value: 'hard_light', icon: _icon(P.zap),          label: t('color_strip.composite.blend_mode.hard_light'), desc: t('color_strip.composite.blend_mode.hard_light.desc') },
+        { value: 'difference', icon: _icon(P.activity),     label: t('color_strip.composite.blend_mode.difference'), desc: t('color_strip.composite.blend_mode.difference.desc') },
+        { value: 'exclusion',  icon: _icon(P.circleOff),    label: t('color_strip.composite.blend_mode.exclusion'),  desc: t('color_strip.composite.blend_mode.exclusion.desc') },
+        { value: 'override',   icon: _icon(P.eye),          label: t('color_strip.composite.blend_mode.override'),   desc: t('color_strip.composite.blend_mode.override.desc') },
     ];
 }
 
@@ -127,11 +132,9 @@ export function compositeRenderList() {
                     <div class="composite-layer-row">
                         <select class="composite-layer-source" data-idx="${i}">${srcOptions}</select>
                         <select class="composite-layer-blend" data-idx="${i}">
-                            <option value="normal"${layer.blend_mode === 'normal' ? ' selected' : ''}>${t('color_strip.composite.blend_mode.normal')}</option>
-                            <option value="add"${layer.blend_mode === 'add' ? ' selected' : ''}>${t('color_strip.composite.blend_mode.add')}</option>
-                            <option value="multiply"${layer.blend_mode === 'multiply' ? ' selected' : ''}>${t('color_strip.composite.blend_mode.multiply')}</option>
-                            <option value="screen"${layer.blend_mode === 'screen' ? ' selected' : ''}>${t('color_strip.composite.blend_mode.screen')}</option>
-                            <option value="override"${layer.blend_mode === 'override' ? ' selected' : ''}>${t('color_strip.composite.blend_mode.override')}</option>
+                            ${_getCompositeBlendItems().map(b =>
+                                `<option value="${b.value}"${layer.blend_mode === b.value ? ' selected' : ''}>${b.label}</option>`
+                            ).join('')}
                         </select>
                     </div>
                     <div class="composite-layer-row">

server/src/wled_controller/static/locales/en.json

@@ -1183,6 +1183,16 @@
     "color_strip.composite.blend_mode.screen": "Screen",
     "color_strip.composite.blend_mode.screen.desc": "Brightens, inverse of multiply",
     "color_strip.composite.blend_mode.override": "Override",
+    "color_strip.composite.blend_mode.overlay": "Overlay",
+    "color_strip.composite.blend_mode.overlay.desc": "Multiply darks, screen lights",
+    "color_strip.composite.blend_mode.soft_light": "Soft Light",
+    "color_strip.composite.blend_mode.soft_light.desc": "Gentle contrast adjustment",
+    "color_strip.composite.blend_mode.hard_light": "Hard Light",
+    "color_strip.composite.blend_mode.hard_light.desc": "Strong contrast, vivid colors",
+    "color_strip.composite.blend_mode.difference": "Difference",
+    "color_strip.composite.blend_mode.difference.desc": "Absolute color difference",
+    "color_strip.composite.blend_mode.exclusion": "Exclusion",
+    "color_strip.composite.blend_mode.exclusion.desc": "Like difference, lower contrast",
     "color_strip.composite.blend_mode.override.desc": "Black = transparent, bright = opaque",
     "color_strip.composite.opacity": "Opacity",
     "color_strip.composite.brightness": "Brightness",

server/src/wled_controller/static/locales/ru.json

@@ -1148,6 +1148,16 @@
     "color_strip.composite.blend_mode.screen": "Экран",
     "color_strip.composite.blend_mode.screen.desc": "Осветляет, обратное умножение",
     "color_strip.composite.blend_mode.override": "Замена",
+    "color_strip.composite.blend_mode.overlay": "Наложение",
+    "color_strip.composite.blend_mode.overlay.desc": "Умножение тёмных, осветление светлых",
+    "color_strip.composite.blend_mode.soft_light": "Мягкий свет",
+    "color_strip.composite.blend_mode.soft_light.desc": "Мягкая коррекция контраста",
+    "color_strip.composite.blend_mode.hard_light": "Жёсткий свет",
+    "color_strip.composite.blend_mode.hard_light.desc": "Сильный контраст, яркие цвета",
+    "color_strip.composite.blend_mode.difference": "Разница",
+    "color_strip.composite.blend_mode.difference.desc": "Абсолютная разница цветов",
+    "color_strip.composite.blend_mode.exclusion": "Исключение",
+    "color_strip.composite.blend_mode.exclusion.desc": "Как разница, но мягче",
     "color_strip.composite.blend_mode.override.desc": "Чёрный = прозрачный, яркий = непрозрачный",
     "color_strip.composite.opacity": "Непрозрачность",
     "color_strip.composite.brightness": "Яркость",

server/src/wled_controller/static/locales/zh.json

@@ -1148,6 +1148,16 @@
     "color_strip.composite.blend_mode.screen": "滤色",
     "color_strip.composite.blend_mode.screen.desc": "提亮，正片叠底的反转",
     "color_strip.composite.blend_mode.override": "覆盖",
+    "color_strip.composite.blend_mode.overlay": "叠加",
+    "color_strip.composite.blend_mode.overlay.desc": "暗部相乘，亮部滤色",
+    "color_strip.composite.blend_mode.soft_light": "柔光",
+    "color_strip.composite.blend_mode.soft_light.desc": "柔和对比度调整",
+    "color_strip.composite.blend_mode.hard_light": "强光",
+    "color_strip.composite.blend_mode.hard_light.desc": "强对比度，鲜艳色彩",
+    "color_strip.composite.blend_mode.difference": "差值",
+    "color_strip.composite.blend_mode.difference.desc": "绝对颜色差异",
+    "color_strip.composite.blend_mode.exclusion": "排除",
+    "color_strip.composite.blend_mode.exclusion.desc": "类似差值，对比度更低",
     "color_strip.composite.blend_mode.override.desc": "黑色=透明，亮色=不透明",
     "color_strip.composite.opacity": "不透明度",
     "color_strip.composite.brightness": "亮度",