1 files changed, 292 insertions, 0 deletions
diff --git a/FrontEnd/src/utilities/geometry.ts b/FrontEnd/src/utilities/geometry.ts
new file mode 100644
index 00000000..60a8d3d4
--- /dev/null
+++ b/FrontEnd/src/utilities/geometry.ts
@@ -0,0 +1,292 @@
+function clamp(value: number, min: number, max: number): number {
+  return Math.min(Math.max(value, min), max);
+}
+
+export interface Point {
+  x: number;
+  y: number;
+}
+
+export type Movement = Point;
+
+export interface Size {
+  width: number;
+  height: number;
+}
+
+export class Rect {
+  static empty = new Rect(0, 0, 0, 0);
+  static max = new Rect(
+    Number.MIN_VALUE,
+    Number.MIN_VALUE,
+    Number.MAX_VALUE,
+    Number.MAX_VALUE,
+  );
+
+  static from({
+    left,
+    top,
+    width,
+    height,
+  }: {
+    left: number;
+    top: number;
+    width: number;
+    height: number;
+  }): Rect {
+    return new Rect(left, top, width, height);
+  }
+
+  constructor(
+    public left: number,
+    public top: number,
+    public width: number,
+    public height: number,
+  ) {}
+
+  get right(): number {
+    return this.left + this.width;
+  }
+
+  set right(value: number) {
+    this.width = value - this.left;
+  }
+
+  get bottom(): number {
+    return this.top + this.height;
+  }
+
+  set bottom(value: number) {
+    this.height = value - this.top;
+  }
+
+  get ratio(): number {
+    return this.height / this.width;
+  }
+
+  get position(): Point {
+    return {
+      x: this.left,
+      y: this.top,
+    };
+  }
+
+  set position(value: Point) {
+    this.left = value.x;
+    this.top = value.y;
+  }
+
+  get size(): Size {
+    return {
+      width: this.width,
+      height: this.height,
+    };
+  }
+
+  set size(value: Size) {
+    this.width = value.width;
+    this.height = value.height;
+  }
+
+  get normalizedLeft(): number {
+    return this.width >= 0 ? this.left : this.right;
+  }
+
+  get normalizedTop(): number {
+    return this.height >= 0 ? this.top : this.bottom;
+  }
+
+  get normalizedRight(): number {
+    return this.width >= 0 ? this.right : this.left;
+  }
+
+  get normalizedBottom(): number {
+    return this.height >= 0 ? this.bottom : this.top;
+  }
+
+  get normalizedWidth(): number {
+    return Math.abs(this.width);
+  }
+
+  get normalizedHeight(): number {
+    return Math.abs(this.height);
+  }
+
+  get normalizedSize(): Size {
+    return {
+      width: this.normalizedWidth,
+      height: this.normalizedHeight,
+    };
+  }
+
+  get normalizedRatio(): number {
+    return Math.abs(this.ratio);
+  }
+
+  normalize(): Rect {
+    if (this.width < 0) {
+      this.width = -this.width;
+      this.left -= this.width;
+    }
+    if (this.height < 0) {
+      this.height = -this.height;
+      this.top -= this.height;
+    }
+    return this;
+  }
+
+  move(movement: Movement): Rect {
+    this.left += movement.x;
+    this.top += movement.y;
+    return this;
+  }
+
+  expand(size: Size | Point): Rect {
+    if ("x" in size) {
+      this.width += size.x;
+      this.height += size.y;
+    } else {
+      this.width += size.width;
+      this.height += size.height;
+    }
+    return this;
+  }
+
+  copy(): Rect {
+    return new Rect(this.left, this.top, this.width, this.height);
+  }
+}
+
+export function adjustRectToContainer(
+  rect: Rect,
+  container: Rect,
+  mode: "move" | "resize" | "both",
+  options?: {
+    targetRatio?: number;
+    resizeNoFlip?: boolean;
+    ratioCorrectBasedOn?: "bigger" | "smaller" | "width" | "height";
+  },
+): Rect {
+  rect = rect.copy();
+  container = container.copy().normalize();
+
+  if (process.env.NODE_ENV === "development") {
+    if (mode === "move") {
+      if (rect.normalizedWidth > container.width) {
+        console.warn(
+          "adjust rect (move): rect.normalizedWidth > container.normalizedWidth",
+        );
+      }
+      if (rect.normalizedHeight > container.height) {
+        console.warn(
+          "adjust rect (move): rect.normalizedHeight > container.normalizedHeight",
+        );
+      }
+    }
+    if (mode === "resize") {
+      if (rect.left < container.left) {
+        console.warn(
+          "adjust rect (resize): rect.left < container.normalizedLeft",
+        );
+      }
+      if (rect.left > container.right) {
+        console.warn(
+          "adjust rect (resize): rect.left > container.normalizedRight",
+        );
+      }
+      if (rect.top < container.top) {
+        console.warn(
+          "adjust rect (resize): rect.top < container.normalizedTop",
+        );
+      }
+      if (rect.top > container.bottom) {
+        console.warn(
+          "adjust rect (resize): rect.top > container.normalizedBottom",
+        );
+      }
+    }
+  }
+
+  if (mode === "move") {
+    rect.left =
+      rect.width >= 0
+        ? clamp(rect.left, container.left, container.right - rect.width)
+        : clamp(rect.left, container.left - rect.width, container.right);
+    rect.top =
+      rect.height >= 0
+        ? clamp(rect.top, container.top, container.bottom - rect.height)
+        : clamp(rect.top, container.top - rect.height, container.bottom);
+  } else if (mode === "resize") {
+    const noFlip = options?.resizeNoFlip;
+    const newRight = clamp(
+      rect.right,
+      rect.width > 0 && noFlip ? rect.left : container.left,
+      rect.width < 0 && noFlip ? rect.left : container.right,
+    );
+    rect.right = newRight;
+    rect.bottom = clamp(
+      rect.bottom,
+      rect.height > 0 && noFlip ? rect.top : container.top,
+      rect.height < 0 && noFlip ? rect.top : container.bottom,
+    );
+  } else {
+    rect.left = clamp(rect.left, container.left, container.right);
+    rect.top = clamp(rect.top, container.top, container.bottom);
+    rect.right = clamp(rect.right, container.left, container.right);
+    rect.bottom = clamp(rect.bottom, container.top, container.bottom);
+  }
+
+  // Now correct ratio
+  const currentRatio = rect.normalizedRatio;
+  let targetRatio = options?.targetRatio;
+  if (targetRatio != null) targetRatio = Math.abs(targetRatio);
+  if (targetRatio != null && currentRatio !== targetRatio) {
+    const { ratioCorrectBasedOn } = options ?? {};
+
+    const newWidth =
+      (Math.sign(rect.width) * rect.normalizedHeight) / targetRatio;
+    const newHeight =
+      Math.sign(rect.height) * rect.normalizedWidth * targetRatio;
+
+    const newBottom = rect.top + newHeight;
+    const newRight = rect.left + newWidth;
+
+    if (ratioCorrectBasedOn === "width") {
+      if (newBottom >= container.top && newBottom <= container.bottom) {
+        rect.height = newHeight;
+      } else {
+        rect.bottom = clamp(newBottom, container.top, container.bottom);
+        rect.width =
+          (Math.sign(rect.width) * rect.normalizedHeight) / targetRatio;
+      }
+    } else if (ratioCorrectBasedOn === "height") {
+      if (newRight >= container.left && newRight <= container.right) {
+        rect.width = newWidth;
+      } else {
+        rect.right = clamp(newRight, container.left, container.right);
+        rect.height =
+          Math.sign(rect.height) * rect.normalizedWidth * targetRatio;
+      }
+    } else if (ratioCorrectBasedOn === "smaller") {
+      if (currentRatio > targetRatio) {
+        // too tall
+        rect.width =
+          (Math.sign(rect.width) * rect.normalizedHeight) / targetRatio;
+      } else {
+        rect.height =
+          Math.sign(rect.height) * rect.normalizedWidth * targetRatio;
+      }
+    } else {
+      if (currentRatio < targetRatio) {
+        // too wide
+        rect.width =
+          (Math.sign(rect.width) * rect.normalizedHeight) / targetRatio;
+      } else {
+        rect.height =
+          Math.sign(rect.height) * rect.normalizedWidth * targetRatio;
+      }
+    }
+  }
+
+  return rect;
+}