From 0ac77f874487d9dbf16b88448a584cc83e014d82 Mon Sep 17 00:00:00 2001
From: frutiemax <lucas.malo.belanger@gmail.com>
Date: Tue, 11 May 2021 07:16:59 -0400
Subject: [PATCH] Part of #12100 : Use ScreenCoordsXY for
 gfx_draw_line_on_buffer (#14305)

---
 src/openrct2/drawing/Line.cpp | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/src/openrct2/drawing/Line.cpp b/src/openrct2/drawing/Line.cpp
index b6082d8250..15122bc27c 100644
--- a/src/openrct2/drawing/Line.cpp
+++ b/src/openrct2/drawing/Line.cpp
@@ -16,44 +16,43 @@
  * Draws a horizontal line of specified colour to a buffer.
  *  rct2: 0x0068474C
  */
-static void gfx_draw_line_on_buffer(rct_drawpixelinfo* dpi, char colour, int32_t y, int32_t x, int32_t no_pixels)
+static void gfx_draw_line_on_buffer(rct_drawpixelinfo* dpi, char colour, const ScreenCoordsXY& coords, int32_t no_pixels)
 {
-    y -= dpi->y;
+    ScreenCoordsXY offset{ coords.x - dpi->x, coords.y - dpi->y };
 
     // Check to make sure point is in the y range
-    if (y < 0)
+    if (offset.y < 0)
         return;
-    if (y >= dpi->height)
+    if (offset.y >= dpi->height)
         return;
     // Check to make sure we are drawing at least a pixel
     if (!no_pixels)
         no_pixels++;
 
-    x -= dpi->x;
-
     // If x coord outside range leave
-    if (x < 0)
+    if (offset.x < 0)
     {
         // Unless the number of pixels is enough to be in range
-        no_pixels += x;
+        no_pixels += offset.x;
         if (no_pixels <= 0)
             return;
         // Resets starting point to 0 as we don't draw outside the range
-        x = 0;
+        offset.x = 0;
     }
 
     // Ensure that the end point of the line is within range
-    if (x + no_pixels - dpi->width > 0)
+    if (offset.x + no_pixels - dpi->width > 0)
     {
         // If the end point has any pixels outside range
         // cut them off. If there are now no pixels return.
-        no_pixels -= x + no_pixels - dpi->width;
+        no_pixels -= offset.x + no_pixels - dpi->width;
         if (no_pixels <= 0)
             return;
     }
 
     // Get the buffer we are drawing to and move to the first coordinate.
-    uint8_t* bits_pointer = dpi->bits + y * (dpi->pitch + dpi->width) + x;
+    uint8_t* bits_pointer = dpi->bits
+        + offset.y * (static_cast<int64_t>(static_cast<int64_t>(dpi->pitch) + static_cast<int64_t>(dpi->width))) + offset.x;
 
     // Draw the line to the specified colour
     for (; no_pixels > 0; --no_pixels, ++bits_pointer)
@@ -141,14 +140,14 @@ void gfx_draw_line_software(rct_drawpixelinfo* dpi, const ScreenLine& line, int3
     {
         // Vertical lines are drawn 1 pixel at a time
         if (steep)
-            gfx_draw_line_on_buffer(dpi, colour, x, y, 1);
+            gfx_draw_line_on_buffer(dpi, colour, { y, x }, 1);
 
         error -= delta_y;
         if (error < 0)
         {
             // Non vertical lines are drawn with as many pixels in a horizontal line as possible
             if (!steep)
-                gfx_draw_line_on_buffer(dpi, colour, y, x_start, no_pixels);
+                gfx_draw_line_on_buffer(dpi, colour, { x_start, y }, no_pixels);
 
             // Reset non vertical line vars
             x_start = x + 1;
@@ -160,7 +159,7 @@ void gfx_draw_line_software(rct_drawpixelinfo* dpi, const ScreenLine& line, int3
         // Catch the case of the last line
         if (x + 1 == x2 && !steep)
         {
-            gfx_draw_line_on_buffer(dpi, colour, y, x_start, no_pixels);
+            gfx_draw_line_on_buffer(dpi, colour, { x_start, y }, no_pixels);
         }
     }
 }