From c3c3508ae01b2141fffcb53ea548e9ef526594ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marvin=20H=C3=A4user?=
 <8659494+mhaeuser@users.noreply.github.com>
Date: Mon, 8 Mar 2021 15:06:55 +0100
Subject: [PATCH] OpenCanopy: Properly offset pointer image

---
 Platform/OpenCanopy/GuiApp.h     |  2 ++
 Platform/OpenCanopy/OpenCanopy.c | 56 ++++++++++++++++++++++++--------
 2 files changed, 44 insertions(+), 14 deletions(-)

diff --git a/Platform/OpenCanopy/GuiApp.h b/Platform/OpenCanopy/GuiApp.h
index bec2c59f..c598f6dc 100644
--- a/Platform/OpenCanopy/GuiApp.h
+++ b/Platform/OpenCanopy/GuiApp.h
@@ -15,6 +15,8 @@
 
 #define MAX_CURSOR_DIMENSION  144U
 
+#define BOOT_CURSOR_OFFSET  4U
+
 #define BOOT_ENTRY_DIMENSION       144U
 #define BOOT_ENTRY_ICON_DIMENSION  APPLE_DISK_ICON_DIMENSION
 #define BOOT_ENTRY_ICON_SPACE      ((BOOT_ENTRY_DIMENSION - BOOT_ENTRY_ICON_DIMENSION) / 2)
diff --git a/Platform/OpenCanopy/OpenCanopy.c b/Platform/OpenCanopy/OpenCanopy.c
index c7c0c9f9..e6ec8708 100644
--- a/Platform/OpenCanopy/OpenCanopy.c
+++ b/Platform/OpenCanopy/OpenCanopy.c
@@ -58,8 +58,8 @@ STATIC UINT64                        mStartTsc          = 0;
 STATIC UINT8                         mNumValidDrawReqs  = 0;
 STATIC GUI_DRAW_REQUEST              mDrawRequests[4]   = { { 0 } };
 
-STATIC UINT32 mCursorOldX = 0;
-STATIC UINT32 mCursorOldY = 0;
+STATIC INT64                         mPointerOldBaseX = 0;
+STATIC INT64                         mPointerOldBaseY = 0;
 
 #define PIXEL_TO_UINT32(Pixel)  \
   ((UINT32) SIGNATURE_32 ((Pixel)->Blue, (Pixel)->Green, (Pixel)->Red, (Pixel)->Reserved))
@@ -613,6 +613,13 @@ GuiOverlayPointer (
   UINT32            MaxHeight;
   GUI_POINTER_STATE PointerState;
 
+  INT64             BaseX;
+  INT64             BaseY;
+  UINT32            ImageOffsetX;
+  UINT32            ImageOffsetY;
+  UINT32            DrawBaseX;
+  UINT32            DrawBaseY;
+
   ASSERT (DrawContext != NULL);
 
   ASSERT (DrawContext->GetCursorImage != NULL);
@@ -637,16 +644,37 @@ GuiOverlayPointer (
   //
   // Draw the new cursor at the new position.
   //
-  MaxWidth  = MIN (CursorImage->Width, DrawContext->Screen->Width - PointerState.X);
-  MaxHeight = MIN (CursorImage->Height, DrawContext->Screen->Height - PointerState.Y);
+
+  BaseX = (INT64) PointerState.X - BOOT_CURSOR_OFFSET * DrawContext->Scale;
+  if (BaseX < 0) {
+    ImageOffsetX = (UINT32) -BaseX;
+    DrawBaseX    = 0;
+  } else {
+    ImageOffsetX = 0;
+    DrawBaseX    = (UINT32) BaseX;
+  }
+
+  MaxWidth = MIN (CursorImage->Width, (UINT32) (DrawContext->Screen->Width - BaseX));
+
+  BaseY = (INT64) PointerState.Y - BOOT_CURSOR_OFFSET * DrawContext->Scale;
+  if (BaseY < 0) {
+    ImageOffsetY = (UINT32) -BaseY;
+    DrawBaseY    = 0;
+  } else {
+    ImageOffsetY = 0;
+    DrawBaseY    = (UINT32) BaseY;
+  }
+
+  MaxHeight = MIN (CursorImage->Height, (UINT32) (DrawContext->Screen->Height - BaseY));
+
   GuiDrawToBuffer (
     CursorImage,
     0xFF,
     DrawContext,
-    PointerState.X,
-    PointerState.Y,
-    0,
-    0,
+    BaseX,
+    BaseY,
+    ImageOffsetX,
+    ImageOffsetY,
     MaxWidth,
     MaxHeight
     );
@@ -654,14 +682,14 @@ GuiOverlayPointer (
   // Queue a draw request for the newly drawn cursor.
   //
   GuiRequestDraw (
-    PointerState.X,
-    PointerState.Y,
+    DrawBaseX,
+    DrawBaseY,
     MaxWidth,
     MaxHeight
     );
 
-  mCursorOldX = PointerState.X;
-  mCursorOldY = PointerState.Y;
+  mPointerOldBaseX = DrawBaseX;
+  mPointerOldBaseY = DrawBaseY;
 }
 
 /**
@@ -1018,8 +1046,8 @@ GuiDrawLoop (
       //
       GuiRequestDrawCrop (
         DrawContext,
-        mCursorOldX,
-        mCursorOldY,
+        mPointerOldBaseX,
+        mPointerOldBaseY,
         CursorImage->Width,
         CursorImage->Height
         );