技术方向可行

使用鼠标轨迹生成偏移应用到材质上实现扭曲技术可行

Content/Lua/HomeLand/UI/Hearth/Widgets/PreCookCenterWidget.lua

@@ -2,8 +2,7 @@ local DataTableUtils = require("Utils.DataTableUtils")
 local ESlateVisibility = import("ESlateVisibility")
 local SlateBlueprintLibrary = import("SlateBlueprintLibrary")
 local WidgetLayoutLibrary = import("WidgetLayoutLibrary")
-
-
+local BusyGamePlayLibrary = import("BusyGamePlayLibrary")
 
 --- @class PreCookCenterWidget
 --- @field ImgContainer table
@@ -33,6 +32,8 @@ function PreCookCenterWidget:OnInitialized()
     -- self.BtnMain.OnClicked:Add(function()
     --     print("onclicked")
     -- end)
+
+    self.DataTexture = BusyGamePlayLibrary.CreateTextureBuffer(self)
 end
 
 function PreCookCenterWidget:Construct()
@@ -69,7 +70,6 @@ end
 
 local function UpdateOldMouseTrack(old_mouse_tracks, delta_time)
     local new_mouse_tracks = {}
-    -- local new_track = {x=fixed_x, y=fixed_y, remain=1.0}
     for _, track in pairs(old_mouse_tracks) do
         track.remain = track.remain - delta_time
         if track.remain > 0 then
@@ -79,15 +79,6 @@ local function UpdateOldMouseTrack(old_mouse_tracks, delta_time)
     return new_mouse_tracks
 end
 
---- 将鼠标的轨迹坐标规范到以起始点到终点所连直线为x轴的坐标系下
-local function NormalizeTrackParam(mouse_tracks)
-
-end
-
---- 根据指定点坐标，求解三次样条参数
-local function GetSplineParams(normalize_params)
-
-end
 
 local function UpdateCutMaskByTracks(widget, mouse_tracks)
     local FVector2D = import("Vector2D")
@@ -108,32 +99,59 @@ local function UpdateCutMaskByTracks(widget, mouse_tracks)
     render_transform.Scale = scale
     render_transform.Translation = translation
     render_transform.Angle = (math.atan(delta_y, delta_x) / (2 * math.pi)) * 360
-    -- render_transform.Scale = FVector2D(mask_length / 512, 1)
-    print(render_transform.Angle, math.atan(delta_y, delta_x))
 
     widget:SetRenderTransform(render_transform)
---[[
-
-	/** The amount to translate the widget in slate units */
-	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Transform, meta=( Delta = "1" ))
-	FVector2D Translation;
-
-	/** The scale to apply to the widget */
-	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Transform, meta=( UIMin = "-5", UIMax = "5", Delta = "0.05" ))
-	FVector2D Scale;
-
-	/** The amount to shear the widget in slate units */
-	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Transform, meta=( UIMin = "-89", ClampMin = "-89", UIMax = "89", ClampMax = "89", Delta = "1" ))
-	FVector2D Shear;
-
-	/** The angle in degrees to rotate */
-	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Transform, meta=( UIMin = "-180", UIMax = "180", Delta = "1" ))
-	float Angle;
-
-]]
-
 end
 
+
+--- 从起点到终点画一条线，以这条线为新的x坐标轴，将所有的点坐标映射到新坐标系下
+local function TransformCurveToEndpointAxes(points)
+    local A = points[1]
+    local B = points[#points]
+
+    -- 计算向量AB
+    local dx = B.X - A.X
+    local dy = B.Y - A.Y
+    local len = math.sqrt(dx * dx + dy * dy)
+    if len == 0 then
+        return {}
+        -- error("Start and end points are the same, cannot define X-axis.")
+    end
+
+    -- 计算X轴单位向量
+    local ux = dx / len
+    local uy = dy / len
+
+    -- 计算Y轴单位向量（逆时针旋转90度）
+    local vx = -uy
+    local vy = ux
+
+    -- 映射所有点到新坐标系
+    local new_points = {}
+    for i, point in ipairs(points) do
+        local apx = point.X - A.X
+        local apy = point.Y - A.Y
+        local new_x = apx * ux + apy * uy  -- 点积与X轴单位向量
+        local new_y = apx * vx + apy * vy  -- 点积与Y轴单位向量
+        new_points[i] = {X = new_x, Y = new_y}
+    end
+
+    return new_points
+end
+
+
+--- 将曲线的Y坐标规范到(-0.5，0.5)的范围内，供材质使用
+local function NormalizeCurveYToHalfRange(points)
+    if #points < 2 then return end
+    local length = points[#points].X - points[1].X
+    for _, point in pairs(points) do
+        point.Y = - point.Y / length  -- 临时加个取反
+        point.X = point.X / length
+    end
+    return points
+end
+
+
 function PreCookCenterWidget:Tick(geometry, delta_time)
     local size = SlateBlueprintLibrary.GetLocalSize(geometry)
     local cursor_pos = WidgetLayoutLibrary.GetMousePositionOnViewport(self)
@@ -148,28 +166,26 @@ function PreCookCenterWidget:Tick(geometry, delta_time)
     end
 
     -- 计算样条参数
-    local normalize_params = NormalizeTrackParam(mouse_tracks)
-    local A, B, C, D = GetSplineParams(normalize_params)  -- Ax^3 + Bx^2 + Cx + D
+    if #mouse_tracks > 2 then
+        local transformed_tracks = TransformCurveToEndpointAxes(mouse_tracks)
+        local normalize_tracks = NormalizeCurveYToHalfRange(transformed_tracks)
 
-    -- 计算划痕位置
+        local offsets = {}
+        for _, track in pairs(normalize_tracks) do
+            table.insert(offsets, track.Y)
+        end
 
-    UpdateCutMaskByTracks(self.ImgMask, mouse_tracks)
+        BusyGamePlayLibrary.UpdateTextureBuffer(self.DataTexture, offsets)
+
+        local mi = self.ImgMask:GetDynamicMaterial()
+        mi:SetTextureParameterValue("Param", self.DataTexture)
+        mi:SetScalarParameterValue("VertexCount", #offsets)
+        mi:SetScalarParameterValue("SourceWidth", 512)
+        UpdateCutMaskByTracks(self.ImgMask, mouse_tracks)
+    end
 
     self.mouse_tracks = mouse_tracks
-
-
-    -- print(fixed_x, fixed_y, #self.mouse_tracks)
 end
 
 
-
--- function PreCookCenterWidget:LuaMouseButtonDown()
---     print("on mouse button down")
--- end
-
--- function PreCookCenterWidget:LuaMouseButtonUp()
---     print("on mouse button up")
--- end
-
-
 return Class(nil, nil, PreCookCenterWidget)