fix: correct bar animations when “bottom” is > 0

Author: farfromrefug

src/charting/buffer/BarBuffer.ts

@@ -77,9 +77,9 @@ export class BarBuffer extends AbstractBuffer<IBarDataSet> {
 
                 // multiply the height of the rect with the phase
                 if (top > 0) {
-                    top *= this.phaseY;
+                    top = bottom + this.phaseY * (top - bottom);
                 } else {
-                    bottom *= this.phaseY;
+                    bottom = top + this.phaseY * (bottom - top);
                 }
 
                 this.addBar(left, top, right, bottom);
@@ -119,8 +119,11 @@ export class BarBuffer extends AbstractBuffer<IBarDataSet> {
                     }
 
                     // multiply the height of the rect with the phase
-                    top *= this.phaseY;
-                    bottom *= this.phaseY;
+                    if (top > 0) {
+                        top = bottom + this.phaseY * (top - bottom);
+                    } else {
+                        bottom = top + this.phaseY * (bottom - top);
+                    }
 
                     this.addBar(left, top, right, bottom);
                 }

src/charting/buffer/HorizontalBarBuffer.ts

@@ -36,9 +36,9 @@ export class HorizontalBarBuffer extends BarBuffer {
 
                 // multiply the height of the rect with the phase
                 if (right > 0) {
-                    right *= this.phaseY;
+                    right = left + this.phaseY * (right - left);
                 } else {
-                    left *= this.phaseY;
+                    left = right + this.phaseY * (left - right);
                 }
                 this.addBar(left, top, right, bottom);
             } else {
@@ -72,8 +72,11 @@ export class HorizontalBarBuffer extends BarBuffer {
                     }
 
                     // multiply the height of the rect with the phase
-                    right *= this.phaseY;
-                    left *= this.phaseY;
+                    if (right > 0) {
+                        right = left + this.phaseY * (right - left);
+                    } else {
+                        left = right + this.phaseY * (left - right);
+                    }
 
                     this.addBar(left, top, right, bottom);
                 }

src/charting/utils/Transformer.ts

@@ -320,37 +320,24 @@ export class Transformer {
      */
     public rectToPixelPhase(r: Rect, phaseY) {
         // multiply the height of the rect with the phase
-        r.top *= phaseY;
-        r.bottom *= phaseY;
+        if (r.top > 0) {
+            r.top = r.bottom + phaseY * (r.top - r.bottom);
+        } else {
+            r.bottom = r.top + phaseY * (r.bottom - r.top);
+        }
         this.rectValueToPixel(r);
-
-        // this.mMatrixValueToPx.mapRect(r);
-        // this.mViewPortHandler.getMatrixTouch().mapRect(r);
-        // this.mMatrixOffset.mapRect(r);
     }
 
     public rectToPixelPhaseHorizontal(r: Rect, phaseY) {
         // multiply the height of the rect with the phase
-        r.left *= phaseY;
-        r.right *= phaseY;
+        if (r.left > 0) {
+            r.left = r.right + phaseY * (r.left - r.right);
+        } else {
+            r.right = r.left + phaseY * (r.right - r.left);
+        }
         this.rectValueToPixel(r);
-
-        // this.mMatrixValueToPx.mapRect(r);
-        // this.mViewPortHandler.getMatrixTouch().mapRect(r);
-        // this.mMatrixOffset.mapRect(r);
     }
 
-    /**
-     * Transform a rectangle with all matrices with potential animation phases.
-     *
-     * @param r
-     */
-    // public rectValueToPixelHorizontal(r: Rect) {
-    //     this.mMatrixValueToPx.mapRect(r);
-    //     this.mViewPortHandler.getMatrixTouch().mapRect(r);
-    //     this.mMatrixOffset.mapRect(r);
-    // }
-
     /**
      * Transform a rectangle with all matrices with potential animation phases.
      *
@@ -364,10 +351,6 @@ export class Transformer {
             r.right *= phaseY;
         }
         this.rectValueToPixel(r);
-
-        // this.mMatrixValueToPx.mapRect(r);
-        // this.mViewPortHandler.getMatrixTouch().mapRect(r);
-        // this.mMatrixOffset.mapRect(r);
     }
 
     /**