From f5dd217c5d7ae9d2aae9c18247d5d954fa170bf6 Mon Sep 17 00:00:00 2001
From: "Elias G. Perez" <eg642616@gmail.com>
Date: Fri, 10 May 2024 20:36:42 -0600
Subject: [PATCH] [WIP] Stipple implementation for MS Windows

---
 src/image.c   | 32 +++++++++++++++++++++++++++++++-
 src/w32term.c | 38 ++++++++++++++++++++++++++++++++------
 src/w32term.h |  1 +
 3 files changed, 64 insertions(+), 7 deletions(-)

diff --git a/src/image.c b/src/image.c
index e93fc3183af..95da8353787 100644
--- a/src/image.c
+++ b/src/image.c
@@ -602,7 +602,36 @@ image_create_bitmap_from_data (struct frame *f, char *bits,
 			 FRAME_DISPLAY_INFO (XFRAME (frame))->n_planes,
 			 FRAME_DISPLAY_INFO (XFRAME (frame))->n_cbits,
 			 bits);
-  if (! bitmap)
+  Emacs_Pixmap stipple;
+
+  /* code extracted from `w32_create_pixmap_from_bitmap_data` */
+
+  static unsigned char swap_nibble[16]
+    = { 0x0, 0x8, 0x4, 0xc,    /* 0000 1000 0100 1100 */
+        0x2, 0xa, 0x6, 0xe,    /* 0010 1010 0110 1110 */
+        0x1, 0x9, 0x5, 0xd,    /* 0001 1001 0101 1101 */
+        0x3, 0xb, 0x7, 0xf };  /* 0011 1011 0111 1111 */
+  int i, j, w1, w2;
+  unsigned char *data, *p;
+
+  w1 = (width + 7) / 8;         /* nb of 8bits elt in X bitmap */
+  w2 = ((width + 15) / 16) * 2; /* nb of 16bits elt in W32 bitmap */
+  data = alloca (height * w2);
+  memset (data, 0, height * w2);
+  for (i = 0; i < height; i++)
+    {
+      p = data + i*w2;
+      for (j = 0; j < w1; j++)
+	{
+	  /* Bitswap XBM bytes to match how Windows does things.  */
+	  unsigned char c = *bits++;
+	  *p++ = (unsigned char)((swap_nibble[c & 0xf] << 4)
+				 | (swap_nibble[(c>>4) & 0xf]));
+	}
+    }
+  stipple = CreateBitmap (width, height, 1, 1, (char *) data);
+
+  if (!bitmap || !stipple)
     return -1;
 #endif /* HAVE_NTGUI */
 
@@ -681,6 +710,7 @@ image_create_bitmap_from_data (struct frame *f, char *bits,
 
 #ifdef HAVE_NTGUI
   dpyinfo->bitmaps[id - 1].pixmap = bitmap;
+  dpyinfo->bitmaps[id - 1].stipple = stipple;
   dpyinfo->bitmaps[id - 1].hinst = NULL;
   dpyinfo->bitmaps[id - 1].depth = 1;
 #endif /* HAVE_NTGUI */
diff --git a/src/w32term.c b/src/w32term.c
index a9aff304771..c72870e0b67 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -1248,6 +1248,33 @@ w32_clear_glyph_string_rect (struct glyph_string *s,
                  real_w, real_h);
 }
 
+/* Fill background with bitmap S glyph, with GC, X, Y, WIDTH, HEIGHT, HDC. */
+static void
+XFillRectangle (HDC hdc, struct glyph_string *s, Emacs_GC *gc,
+		int x, int y, unsigned int width, unsigned int height)
+{
+  /* NOTE: stipple bitmap has the inverted colors, inverting those 2
+   * functions color must fix this. */
+  SetTextColor (hdc, gc->background);
+  SetBkColor (hdc, gc->foreground);
+
+  Emacs_Pixmap bm;
+  HBRUSH hb;
+
+  bm = FRAME_DISPLAY_INFO (s->f)->bitmaps[s->face->stipple - 1].stipple;
+  hb = CreatePatternBrush (bm);
+
+  /* Is this part below written correctly? */
+  RECT r;
+  r.left = x;
+  r.top = y;
+  r.right = x + width + 1;
+  r.bottom = y + height + 1;
+
+  FillRect (hdc, &r, hb);
+
+  DeleteObject (hb);
+}
 
 /* Draw the background of glyph_string S.  If S->background_filled_p
    is non-zero don't draw it.  FORCE_P non-zero means draw the
@@ -1264,16 +1291,15 @@ w32_draw_glyph_string_background (struct glyph_string *s, bool force_p)
     {
       int box_line_width = max (s->face->box_horizontal_line_width, 0);
 
-#if 0 /* TODO: stipple */
+#if 1 /* TODO: stipple */
       if (s->stippled_p)
 	{
 	  /* Fill background with a stipple pattern.  */
-	  XSetFillStyle (s->display, s->gc, FillOpaqueStippled);
-	  XFillRectangle (s->display, FRAME_W32_WINDOW (s->f), s->gc, s->x,
-			  s->y + box_line_width,
-			  s->background_width,
+	  /* XSetFillStyle (s->display, s->gc, FillOpaqueStippled); */
+	  XFillRectangle (s->hdc, s, s->gc, s->x,
+			  s->y + box_line_width, s->background_width,
 			  s->height - 2 * box_line_width);
-	  XSetFillStyle (s->display, s->gc, FillSolid);
+	  /* XSetFillStyle (s->display, s->gc, FillSolid); */
 	  s->background_filled_p = true;
 	}
       else
diff --git a/src/w32term.h b/src/w32term.h
index 3120c8bd71f..1eb6a660248 100644
--- a/src/w32term.h
+++ b/src/w32term.h
@@ -58,6 +58,7 @@ #define CP_DEFAULT 1004
 {
   Emacs_Pixmap pixmap;
   char *file;
+  Emacs_Pixmap stipple;
   HINSTANCE hinst; /* Used to load the file */
   int refcount;
   /* Record some info about this pixmap.  */
-- 
2.44.0.windows.1