Re: [PATCH v7 1/4] drm/panic: Add integer scaling to blit()

Thomas Zimmermann <tzimmermann@xxxxxxx> · Thu, 22 Aug 2024 14:48:24 +0200

Am 22.08.24 um 09:33 schrieb Jocelyn Falempe:
Add a parameter to the blit function, to upscale the image.
This is necessary to draw a QR code, otherwise, the pixels are
usually too small to be readable by most QR code reader.
It can also be used later for drawing fonts on high DPI display.

Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>

Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

---
  drivers/gpu/drm/drm_panic.c | 33 +++++++++++++++++++--------------
  1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index eff4598e2fc73..0a047152f88b8 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -257,20 +257,20 @@ static bool drm_panic_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, i
  static void drm_panic_blit16(struct iosys_map *dmap, unsigned int dpitch,
  			     const u8 *sbuf8, unsigned int spitch,
  			     unsigned int height, unsigned int width,
-			     u16 fg16)
+			     unsigned int scale, u16 fg16)
  {
  	unsigned int y, x;
  
  	for (y = 0; y < height; y++)
  		for (x = 0; x < width; x++)
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y))
+			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
  				iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16);
  }
  
  static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
  			     const u8 *sbuf8, unsigned int spitch,
  			     unsigned int height, unsigned int width,
-			     u32 fg32)
+			     unsigned int scale, u32 fg32)
  {
  	unsigned int y, x;
  
@@ -278,7 +278,7 @@ static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
  		for (x = 0; x < width; x++) {
  			u32 off = y * dpitch + x * 3;
  
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y)) {
+			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {
  				/* write blue-green-red to output in little endianness */
  				iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0);
  				iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8);
@@ -291,24 +291,25 @@ static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
  static void drm_panic_blit32(struct iosys_map *dmap, unsigned int dpitch,
  			     const u8 *sbuf8, unsigned int spitch,
  			     unsigned int height, unsigned int width,
-			     u32 fg32)
+			     unsigned int scale, u32 fg32)
  {
  	unsigned int y, x;
  
  	for (y = 0; y < height; y++)
  		for (x = 0; x < width; x++)
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y))
+			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
  				iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32);
  }
  
  static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip,
-				 const u8 *sbuf8, unsigned int spitch, u32 fg_color)
+				 const u8 *sbuf8, unsigned int spitch, unsigned int scale,
+				 u32 fg_color)
  {
  	unsigned int y, x;
  
  	for (y = 0; y < drm_rect_height(clip); y++)
  		for (x = 0; x < drm_rect_width(clip); x++)
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y))
+			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
  				sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color);
  }
  
@@ -318,18 +319,22 @@ static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect
   * @clip: destination rectangle
   * @sbuf8: source buffer, in monochrome format, 8 pixels per byte.
   * @spitch: source pitch in bytes
+ * @scale: integer scale, source buffer is scale time smaller than destination
+ *         rectangle
   * @fg_color: foreground color, in destination format
   *
   * This can be used to draw a font character, which is a monochrome image, to a
   * framebuffer in other supported format.
   */
  static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
-			   const u8 *sbuf8, unsigned int spitch, u32 fg_color)
+			   const u8 *sbuf8, unsigned int spitch,
+			   unsigned int scale, u32 fg_color)
+
  {
  	struct iosys_map map;
  
  	if (sb->set_pixel)
-		return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, fg_color);
+		return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, scale, fg_color);
  
  	map = sb->map[0];
  	iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);
@@ -337,15 +342,15 @@ static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
  	switch (sb->format->cpp[0]) {
  	case 2:
  		drm_panic_blit16(&map, sb->pitch[0], sbuf8, spitch,
-				 drm_rect_height(clip), drm_rect_width(clip), fg_color);
+				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
  	break;
  	case 3:
  		drm_panic_blit24(&map, sb->pitch[0], sbuf8, spitch,
-				 drm_rect_height(clip), drm_rect_width(clip), fg_color);
+				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
  	break;
  	case 4:
  		drm_panic_blit32(&map, sb->pitch[0], sbuf8, spitch,
-				 drm_rect_height(clip), drm_rect_width(clip), fg_color);
+				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
  	break;
  	default:
  		WARN_ONCE(1, "Can't blit with pixel width %d\n", sb->format->cpp[0]);
@@ -485,7 +490,7 @@ static void draw_txt_rectangle(struct drm_scanout_buffer *sb,
  		for (j = 0; j < line_len; j++) {
  			src = get_char_bitmap(font, msg[i].txt[j], font_pitch);
  			rec.x2 = rec.x1 + font->width;
-			drm_panic_blit(sb, &rec, src, font_pitch, color);
+			drm_panic_blit(sb, &rec, src, font_pitch, 1, color);
  			rec.x1 += font->width;
  		}
  	}

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)







