Reverse framebuffer vertical coordinates to start with 0 at top

src/hulk/console.d

@@ -6,6 +6,11 @@ module hulk.console;
 import hulk.fb;
 import hulk.kfont;
 
+/**
+ * Represent the HULK console.
+ *
+ * Coordinate (0,0) is the top-left console position.
+ */
 struct Console
 {
     /** Console width in text columns. */
@@ -64,7 +69,7 @@ struct Console
         if (m_y == m_height)
         {
             m_y--;
-            Fb.copy_rows_up(fb_y(m_height - 1u),
+            Fb.copy_rows_up(fb_y(1u),
                     (m_height - 1u) * Kfont.line_height,
                     Kfont.line_height);
             Fb.rect(0u, fb_y(m_height - 1u), fb_x(m_width), Kfont.line_height, 0u);
@@ -81,7 +86,7 @@ struct Console
     private static void render_char(size_t x, size_t y, char ch)
     {
         const(CharInfo) * ci = &Kfont.chars[ch];
-        Fb.blit_alpha_bitmap(fb_x(x) + ci.left, fb_y(y) + Kfont.baseline_offset + ci.top - ci.height, ci.bitmap, ci.width, ci.height);
+        Fb.blit_alpha_bitmap(fb_x(x) + ci.left, fb_y(y) + Kfont.line_height - Kfont.baseline_offset - ci.top, ci.bitmap, ci.width, ci.height);
     }
 
     /**
@@ -97,6 +102,6 @@ struct Console
      */
     private static size_t fb_y(size_t y)
     {
-        return Fb.height - ((y + 1u) * Kfont.line_height);
+        return y * Kfont.line_height;
     }
 }