From d764221d63be31533a556aaf244cea8299d42151 Mon Sep 17 00:00:00 2001
From: Victor Seiji Hariki <victorseijih@gmail.com>
Date: Thu, 12 Jan 2023 21:49:06 -0300
Subject: [PATCH] support select tool rotation

Signed-off-by: Victor Seiji Hariki <victorseijih@gmail.com>
---
 index.html            |   6 +--
 js/config.js          |  15 ++++++
 js/ui/tool/generic.js |  75 ++++++++++++++++++++------
 js/ui/tool/select.js  | 122 ++++++++++++++++++++++--------------------
 4 files changed, 140 insertions(+), 78 deletions(-)

diff --git a/index.html b/index.html
index 48a63c1..8ff9d89 100644
--- a/index.html
+++ b/index.html
@@ -355,7 +355,7 @@
 			type="text/javascript"></script>
 
 		<!-- Configuration -->
-		<script src="js/config.js?v=664f6ee" type="text/javascript"></script>
+		<script src="js/config.js?v=36739c9" type="text/javascript"></script>
 
 		<!-- Content -->
 		<script src="js/prompt.js?v=7a1c68c" type="text/javascript"></script>
@@ -370,7 +370,7 @@
 
 		<!-- Load Tools -->
 		<script
-			src="js/ui/tool/generic.js?v=9f1f84e"
+			src="js/ui/tool/generic.js?v=f5ad9d7"
 			type="text/javascript"></script>
 
 		<script src="js/ui/tool/dream.js?v=95c916d" type="text/javascript"></script>
@@ -381,7 +381,7 @@
 			src="js/ui/tool/colorbrush.js?v=3f8c01a"
 			type="text/javascript"></script>
 		<script
-			src="js/ui/tool/select.js?v=26b80dd"
+			src="js/ui/tool/select.js?v=fae1b04"
 			type="text/javascript"></script>
 		<script src="js/ui/tool/stamp.js?v=3c07ac8" type="text/javascript"></script>
 		<script
diff --git a/js/config.js b/js/config.js
index 6b49e15..8133dab 100644
--- a/js/config.js
+++ b/js/config.js
@@ -21,6 +21,21 @@ const config = makeReadOnly(
 		// Rotate Handle Distance (from selection)
 		rotateHandleDistance: 32,
 
+		// Rotation Snapping Distance
+		rotationSnappingDistance: (10 * Math.PI) / 180,
+		// Rotation Snapping Angles
+		rotationSnappingAngles: [
+			0,
+			Math.PI / 4,
+			Math.PI / 2,
+			(Math.PI * 3) / 4,
+			Math.PI,
+			(Math.PI * 5) / 4,
+			(Math.PI * 6) / 4,
+			(Math.PI * 7) / 4,
+			Math.PI * 2,
+		],
+
 		// Endpoint
 		api: makeReadOnly({path: "/sdapi/v1/"}),
 	},
diff --git a/js/ui/tool/generic.js b/js/ui/tool/generic.js
index b4ee0d4..62d19f1 100644
--- a/js/ui/tool/generic.js
+++ b/js/ui/tool/generic.js
@@ -398,39 +398,55 @@ const _tool = {
 			);
 		}
 
-		hoveringHandle(x, y) {
+		hoveringRotateHandle(x, y, scale = 1) {
+			const localc = this.matrix.inverse().transformPoint({x, y});
+			const localrh = {
+				x: 0,
+				y: -this.canvas.height / 2 - config.rotateHandleDistance * scale,
+			};
+
+			const dx = Math.abs(localc.x - localrh.x);
+			const dy = Math.abs(localc.y - localrh.y);
+
+			return (
+				dx * dx + dy * dy <
+				(scale * scale * config.handleDetectSize * config.handleDetectSize) / 4
+			);
+		}
+
+		hoveringHandle(x, y, scale = 1) {
 			const localbb = new BoundingBox({
-				x: -this.canvas.width / 2,
-				y: -this.canvas.height / 2,
-				w: this.canvas.width,
-				h: this.canvas.height,
+				x: (this.scale.x * -this.canvas.width) / 2,
+				y: (this.scale.y * -this.canvas.height) / 2,
+				w: this.canvas.width * this.scale.x,
+				h: this.canvas.height * this.scale.y,
 			});
 
-			const localc = this.matrix.inverse().transformPoint({x, y});
+			const localc = this.rtmatrix.inverse().transformPoint({x, y});
 			const ontl =
 				Math.max(
 					Math.abs(localc.x - localbb.tl.x),
 					Math.abs(localc.y - localbb.tl.y)
 				) <
-				config.handleDetectSize / 2;
+				(config.handleDetectSize / 2) * scale;
 			const ontr =
 				Math.max(
 					Math.abs(localc.x - localbb.tr.x),
 					Math.abs(localc.y - localbb.tr.y)
 				) <
-				config.handleDetectSize / 2;
+				(config.handleDetectSize / 2) * scale;
 			const onbl =
 				Math.max(
 					Math.abs(localc.x - localbb.bl.x),
 					Math.abs(localc.y - localbb.bl.y)
 				) <
-				config.handleDetectSize / 2;
+				(config.handleDetectSize / 2) * scale;
 			const onbr =
 				Math.max(
 					Math.abs(localc.x - localbb.br.x),
 					Math.abs(localc.y - localbb.br.y)
 				) <
-				config.handleDetectSize / 2;
+				(config.handleDetectSize / 2) * scale;
 
 			return {onHandle: ontl || ontr || onbl || onbr, ontl, ontr, onbl, onbr};
 		}
@@ -459,6 +475,8 @@ const _tool = {
 		 * @param {DOMMatrix} transform A transformation matrix to transform the position by
 		 */
 		drawBox(context, cursor, transform = new DOMMatrix()) {
+			const drawscale =
+				1 / Math.sqrt(transform.a * transform.a + transform.b * transform.b);
 			const m = transform.multiply(this.matrix);
 
 			context.save();
@@ -496,13 +514,32 @@ const _tool = {
 			context.lineTo(tl.x, tl.y);
 			context.stroke();
 
+			// Draw rotation handle
+			context.setLineDash([]);
+
+			const hm = new DOMMatrix().rotateSelf((this.rotation * 180) / Math.PI);
+			const tm = m.transformPoint({x: 0, y: -this.canvas.height / 2});
+			const rho = hm.transformPoint({x: 0, y: -config.rotateHandleDistance});
+			const rh = {x: tm.x + rho.x, y: tm.y + rho.y};
+
+			let handleRadius = config.handleDrawSize / 2;
+			if (this.hoveringRotateHandle(cursor.x, cursor.y, drawscale))
+				handleRadius *= config.handleDrawHoverScale;
+
+			context.beginPath();
+			context.moveTo(tm.x, tm.y);
+			context.lineTo(rh.x, rh.y);
+			context.stroke();
+
+			context.beginPath();
+			context.arc(rh.x, rh.y, handleRadius, 0, 2 * Math.PI);
+			context.stroke();
+
 			// Draw handles
 			const drawHandle = (pt, hover) => {
 				let hsz = config.handleDrawSize / 2;
 				if (hover) hsz *= config.handleDrawHoverScale;
 
-				const hm = new DOMMatrix().rotateSelf(this.rotation);
-
 				const htl = hm.transformPoint({x: -hsz, y: -hsz});
 				const htr = hm.transformPoint({x: hsz, y: -hsz});
 				const hbr = hm.transformPoint({x: hsz, y: hsz});
@@ -521,7 +558,11 @@ const _tool = {
 			context.lineWidth = 2;
 			context.setLineDash([]);
 
-			const {ontl, ontr, onbl, onbr} = this.hoveringHandle(cursor.x, cursor.y);
+			const {ontl, ontr, onbl, onbr} = this.hoveringHandle(
+				cursor.x,
+				cursor.y,
+				drawscale
+			);
 
 			drawHandle(tl, ontl);
 			drawHandle(tr, ontr);
@@ -533,10 +574,10 @@ const _tool = {
 			return () => {
 				const border = config.handleDrawSize * config.handleDrawHoverScale;
 
-				const minx = Math.min(tl.x, tr.x, bl.x, br.x) - border;
-				const maxx = Math.max(tl.x, tr.x, bl.x, br.x) + border;
-				const miny = Math.min(tl.y, tr.y, bl.y, br.y) - border;
-				const maxy = Math.max(tl.y, tr.y, bl.y, br.y) + border;
+				const minx = Math.min(tl.x, tr.x, bl.x, br.x, rh.x) - border;
+				const maxx = Math.max(tl.x, tr.x, bl.x, br.x, rh.x) + border;
+				const miny = Math.min(tl.y, tr.y, bl.y, br.y, rh.y) - border;
+				const maxy = Math.max(tl.y, tr.y, bl.y, br.y, rh.y) + border;
 
 				context.clearRect(minx, miny, maxx - minx, maxy - miny);
 			};
diff --git a/js/ui/tool/select.js b/js/ui/tool/select.js
index 9071e41..eac3c29 100644
--- a/js/ui/tool/select.js
+++ b/js/ui/tool/select.js
@@ -111,6 +111,12 @@ const selectTransformTool = () =>
 					}
 				};
 
+				/** @type {{selected: Point, offset: Point} | null} */
+				let moving = null;
+				/** @type {{handle: Point} | null} */
+				let scaling = null;
+				let rotating = false;
+
 				// Clears selection and make things right
 				state.reset = (erase = false) => {
 					if (state.selected && !erase)
@@ -129,7 +135,9 @@ const selectTransformTool = () =>
 
 					state.rotation = 0;
 					state.original = null;
-					state.moving = false;
+					moving = null;
+					scaling = null;
+					rotating = null;
 
 					state.redraw();
 				};
@@ -137,11 +145,6 @@ const selectTransformTool = () =>
 				// Selection Handlers
 				const selection = _tool._draggable_selection(state);
 
-				/** @type {{selected: Point, offset: Point} | null} */
-				let moving = null;
-				/** @type {{handle: Point} | null} */
-				let scaling = null;
-
 				// UI Erasers
 				let eraseSelectedBox = () => null;
 				let eraseSelectedImage = () => null;
@@ -191,7 +194,8 @@ const selectTransformTool = () =>
 
 						if (
 							state.selected.hoveringBox(x, y) ||
-							state.selected.hoveringHandle(x, y).onHandle
+							state.selected.hoveringHandle(x, y, viewport.zoom).onHandle ||
+							state.selected.hoveringRotateHandle(x, y, viewport.zoom)
 						) {
 							imageCollection.inputElement.style.cursor = "pointer";
 						}
@@ -286,11 +290,16 @@ const selectTransformTool = () =>
 
 					if (state.selected) {
 						const hoveringBox = state.selected.hoveringBox(ix, iy);
-						const hoveringHandle = state.selected.hoveringHandle(ix, iy);
-
-						const localc = state.selected.matrix
-							.inverse()
-							.transformPoint({x: ix, y: iy});
+						const hoveringHandle = state.selected.hoveringHandle(
+							ix,
+							iy,
+							viewport.zoom
+						);
+						const hoveringRotateHandle = state.selected.hoveringRotateHandle(
+							ix,
+							iy,
+							viewport.zoom
+						);
 
 						if (hoveringBox) {
 							// Start dragging
@@ -327,38 +336,56 @@ const selectTransformTool = () =>
 								handle,
 							};
 							return;
+						} else if (hoveringRotateHandle) {
+							rotating = true;
+							return;
 						}
 					}
 					selection.dragstartcb(evn);
 				};
 
+				const transform = (evn, x, y, sx, sy) => {
+					if (moving) {
+						state.selected.position = {
+							x: sx - moving.offset.x,
+							y: sy - moving.offset.y,
+						};
+					}
+
+					if (scaling) {
+						/** @type {DOMMatrix} */
+						const m = state.selected.rtmatrix.invertSelf();
+						const lscursor = m.transformPoint({x: sx, y: sy});
+
+						const xs = lscursor.x / scaling.handle.x;
+						const xy = lscursor.y / scaling.handle.y;
+
+						if (!state.keepAspectRatio) state.selected.scale = {x: xs, y: xy};
+						else {
+							const scale = Math.max(xs, xy);
+							state.selected.scale = {x: scale, y: scale};
+						}
+					}
+
+					if (rotating) {
+						const center = state.selected.matrix.transformPoint({x: 0, y: 0});
+						let angle = Math.atan2(x - center.x, center.y - y);
+
+						if (evn.evn.shiftKey)
+							angle =
+								config.rotationSnappingAngles.find(
+									(v) => Math.abs(v - angle) < config.rotationSnappingDistance
+								) || angle;
+
+						state.selected.rotation = angle;
+					}
+				};
+
 				// Handles left mouse drag events
 				state.dragcb = (evn) => {
 					const {x, y, sx, sy} = _tool._process_cursor(evn, state.snapToGrid);
 
-					if (state.selected) {
-						if (moving) {
-							state.selected.position = {
-								x: sx - moving.offset.x,
-								y: sy - moving.offset.y,
-							};
-						}
-
-						if (scaling) {
-							/** @type {DOMMatrix} */
-							const m = state.selected.rtmatrix.invertSelf();
-							const lscursor = m.transformPoint({x: sx, y: sy});
-
-							const xs = lscursor.x / scaling.handle.x;
-							const xy = lscursor.y / scaling.handle.y;
-
-							if (!state.keepAspectRatio) state.selected.scale = {x: xs, y: xy};
-							else {
-								const scale = Math.max(xs, xy);
-								state.selected.scale = {x: scale, y: scale};
-							}
-						}
-					}
+					if (state.selected) transform(evn, x, y, sx, sy);
 
 					if (selection.exists) selection.dragcb(evn);
 				};
@@ -406,32 +433,11 @@ const selectTransformTool = () =>
 						selection.deselect();
 					}
 
-					if (state.selected) {
-						if (moving) {
-							state.selected.position = {
-								x: sx - moving.offset.x,
-								y: sy - moving.offset.y,
-							};
-						}
-
-						if (scaling) {
-							/** @type {DOMMatrix} */
-							const m = state.selected.rtmatrix.invertSelf();
-							const lscursor = m.transformPoint({x: sx, y: sy});
-
-							const xs = lscursor.x / scaling.handle.x;
-							const xy = lscursor.y / scaling.handle.y;
-
-							if (!state.keepAspectRatio) state.selected.scale = {x: xs, y: xy};
-							else {
-								const scale = Math.max(xs, xy);
-								state.selected.scale = {x: scale, y: scale};
-							}
-						}
-					}
+					if (state.selected) transform(evn, x, y, sx, sy);
 
 					moving = null;
 					scaling = null;
+					rotating = false;
 
 					state.redraw();
 				};