From 37a532236bfd32a61d1777353e507077af617621 Mon Sep 17 00:00:00 2001
From: unsettledgames <47360416+unsettledgames@users.noreply.github.com>
Date: Thu, 17 Sep 2020 16:11:00 +0200
Subject: [PATCH] Fixed brush preview snapping

---
 js/_getCursorPosition.js |  2 +-
 js/_mouseEvents.js       | 13 ++++++++++---
 js/_tools.js             | 10 ++++++++--
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/js/_getCursorPosition.js b/js/_getCursorPosition.js
index 0452e16..4c9cdca 100644
--- a/js/_getCursorPosition.js
+++ b/js/_getCursorPosition.js
@@ -2,7 +2,7 @@
 function getCursorPosition(e) {
     var x;
     var y;
-
+    
     if (e.pageX != undefined && e.pageY != undefined) {
         x = e.pageX;
         y = e.pageY;
diff --git a/js/_mouseEvents.js b/js/_mouseEvents.js
index 6342030..de0a386 100644
--- a/js/_mouseEvents.js
+++ b/js/_mouseEvents.js
@@ -157,16 +157,23 @@ window.addEventListener("mouseup", function (mouseEvent) {
 }, false);
 
 // TODO: Make it snap to the pixel grid
-function setPreviewPosition(preview, cursor, size){
+function setPreviewPosition(preview, size){
+	let toAdd = 0;
+
+	// This prevents the brush to be placed in the middle of pixels
+	if (size % 2 == 0) {
+		toAdd = 0.5;
+	}
+
     preview.style.left = (
         currentLayer.canvas.offsetLeft
         + Math.floor(cursor[0]/zoom) * zoom
-        - Math.floor(size / 2) * zoom
+        - Math.floor(size / 2) * zoom + toAdd
     ) + 'px';
     preview.style.top = (
         currentLayer.canvas.offsetTop
         + Math.floor(cursor[1]/zoom) * zoom
-        - Math.floor(size / 2) * zoom
+        - Math.floor(size / 2) * zoom + toAdd
     ) + 'px';
 }
 
diff --git a/js/_tools.js b/js/_tools.js
index 335c09a..3c10d70 100644
--- a/js/_tools.js
+++ b/js/_tools.js
@@ -95,8 +95,14 @@ class Tool {
 	}
 
 	moveBrushPreview(cursorLocation) {
-		brushPreview.style.left = (Math.ceil(cursorLocation[0] / zoom) * zoom + currentLayer.canvas.offsetLeft - this.currentBrushSize * zoom / 2 - zoom / 2) + 'px';
-		brushPreview.style.top = (Math.ceil(cursorLocation[1] / zoom) * zoom + currentLayer.canvas.offsetTop - this.currentBrushSize * zoom / 2 - zoom / 2) + 'px';
+		let toSub = 0;
+		// Prevents the brush to be put in the middle of pixels
+		if (this.currentBrushSize % 2 == 0) {
+			toSub = 0.5;
+		}		
+
+		brushPreview.style.left = (Math.ceil(cursorLocation[0] / zoom) * zoom + currentLayer.canvas.offsetLeft - this.currentBrushSize * zoom / 2 - zoom / 2 - toSub * zoom) + 'px';
+		brushPreview.style.top = (Math.ceil(cursorLocation[1] / zoom) * zoom + currentLayer.canvas.offsetTop - this.currentBrushSize * zoom / 2 - zoom / 2 - toSub * zoom) + 'px';
 	}
 }