From c91757308dfb6f109c9e31149dab7dbe6365042c Mon Sep 17 00:00:00 2001
From: Torrie Fischer <torrie@ripple.com>
Date: Mon, 11 Dec 2023 07:47:54 +0100
Subject: [PATCH] figments: surface: handle swapped start/end positions

---
 lib/Figments/Surface.cpp | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/Figments/Surface.cpp b/lib/Figments/Surface.cpp
index 5676f1d..d05a35d 100644
--- a/lib/Figments/Surface.cpp
+++ b/lib/Figments/Surface.cpp
@@ -54,17 +54,20 @@ void
 Surface::paintShader(Surface::Shader shader)
 {
     PerfCounter _("paintShader");
-    const uint16_t width = end.x - start.x + 1;
-    const uint16_t height = end.y - start.y + 1;
+    uint8_t startX = min(start.x, end.x);
+    uint8_t startY = min(start.y, end.y);
+    uint8_t endX = max(start.x, end.x);
+    uint8_t endY = max(start.y, end.y);
+    const uint16_t width = endX - startX + 1;
+    const uint16_t height = endY - startY + 1;
     const uint8_t xMod = 255 / width;
     const uint8_t yMod = 255 / height;
     for(auto x = 0; x < width; x++) {
         for(auto y = 0; y < height; y++) {
-            PhysicalCoordinates coords{x + start.x, y + start.y};
+            PhysicalCoordinates coords{x + startX, y + startY};
             VirtualCoordinates virtCoords{m_display->coordinateMapping()->physicalToVirtualCoords(coords)};
             VirtualCoordinates surfaceCoords{xMod * x, yMod * y};
-            //Log.notice("width=%d height=%d vx=%d vy=%d sx=%d sy=%d x=%d y=%d px=%d py=%d", width, height, start.x, start.y, x, y, coords.x, coords.y);
-            // 256 = 1.0
+            //Log.notice("width=%d height=%d vx=%d vy=%d sx=%d sy=%d x=%d y=%d px=%d py=%d", width, height, startX, startY, x, y, coords.x, coords.y); // 256 = 1.0
             // 128 = 0.0
             // 0 = 1.0
             shader(m_display->pixelAt(coords), virtCoords, coords, surfaceCoords);