Attachment 6500 Details for Bug 7814 – (Shorter) Patch implementing swizzle + simple antialiasing

[patch] (Shorter) Patch implementing swizzle + simple antialiasing

xephyr_swizzle.diff (text/plain), 7.44 KB, created by Manu Cornet on 2006-08-08 11:13:08 UTC

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Creator: Manu Cornet

Created: 2006-08-08 11:13:08 UTC

Size: 7.44 KB

patch

obsolete

>--- hostx.c.orig	2006-07-24 11:31:07.000000000 +0200
>+++ hostx.c	2006-08-08 20:06:10.000000000 +0200
>@@ -67,6 +67,7 @@
>   long            damage_debug_msec;
> 
>   unsigned char  *fb_data;   	/* only used when host bpp != server bpp */
>+  unsigned char  *original_fb;  /* Only used in color swizzling & AA mode */
>   unsigned long   cmap[256];
> 
>   XShmSegmentInfo shminfo;
>@@ -87,6 +88,8 @@
> extern int	      kdKeymapWidth;
> extern int            monitorResolution;
> 
>+int swizzle = 1;
>+
> static void
> hostx_set_fullscreen_hint(void);
> 
>@@ -553,6 +556,16 @@
>     }
> }
> 
>+#define MAKE_24BITS_PIXEL_FROM_16BITS(server_pixel) ((((server_pixel & 0xf800) >> 8) << 16) | (((server_pixel & 0x07e0) >> 3) << 8) | ((server_pixel & 0x001f) << 3))
>+
>+static void
>+copy_16bits_pixel_into_host_fb (unsigned char *host, unsigned short server_pixel) {
>+
>+  host[2] = ((server_pixel & 0xf800) >> 8);
>+  host[1] = ((server_pixel & 0x07e0) >> 3);
>+  host[0] = ((server_pixel & 0x001f) << 3);
>+}
>+
> void
> hostx_paint_rect(int sx,    int sy,
> 		 int dx,    int dy, 
>@@ -563,6 +576,23 @@
>    *  on to the window
>    */
> 
>+  int x_min = 0, x_max = 0, y_min = 0, y_max = 0;
>+  
>+  static Bool swizzle_initialized = 0;
>+  
>+  /* 
>+   * The color swizzling mode was designed to simulate the "One Laptop
>+   * Per Child" display, for which 16bit colors are best.
>+   */
>+  if (swizzle && HostX.server_depth != 16) {
>+    fprintf (stderr, "Warning: you asked for color swizzling but the server's depth is different from 16 bit, swizzling is disabled.\n");
>+  }
>+  
>+  if (swizzle && !swizzle_initialized) {
>+    HostX.original_fb = (unsigned char *) malloc (HostX.ximg->bytes_per_line * HostX.ximg->height);
>+    swizzle_initialized = 1;
>+  }
>+
>   if (HostXWantDamageDebug)
>     {
>       hostx_paint_debug_rect(dx, dy, width, height);
>@@ -582,51 +612,132 @@
> 
>   if (!host_depth_matches_server())
>     {
>-      int            x,y,idx, bytes_per_pixel = (HostX.server_depth>>3);
>-      unsigned char  r,g,b;
>-      unsigned long  host_pixel;
>-
>-      for (y=sy; y<sy+height; y++)
>-	for (x=sx; x<sx+width; x++)
>-	  {
>-	    idx = (HostX.win_width*y*bytes_per_pixel)+(x*bytes_per_pixel);
>+      int            x, y, idx, server_bpp = (HostX.server_depth>>3), host_bpp = HostX.ximg->bits_per_pixel / 8;
>+      unsigned char  r, g, b, aa_color;
>+      unsigned char *host_pixel;
>+      unsigned long  final_host_pixel;
>+      
>+      if (swizzle) {
>+	int border, sum, swizzle_position;
>+	unsigned short server_pixel;
>+	
>+	border = 1;
>+	x_min = (sx - border < 0)? 0 : sx - border;
>+	y_min = (sy - border < 0)? 0 : sy - border;
>+	x_max = (sx + width  + border > HostX.ximg->width)?  HostX.ximg->width  : sx + width  + border;
>+	y_max = (sy + height + border > HostX.ximg->height)? HostX.ximg->height : sy + height + border;
>+	
>+	/* First, update the zone we're redrawing in the local,
>+	 * unaltered framebuffer.
>+	 */
>+	
>+	for (y = sy; y < sy + height; y++) {
>+	  for (x = sx; x < sx + width; x++) {
>+	    idx = (HostX.win_width * y + x) * server_bpp;
>+	    server_pixel = *(unsigned short*)(HostX.fb_data+idx);
>+	    host_pixel = HostX.original_fb + (x + y * HostX.ximg->width) * host_bpp;
>+	    copy_16bits_pixel_into_host_fb (host_pixel, server_pixel);
>+	  }
>+	}
>+	
>+	/* 
>+	 * Then, perform the antialiasing the way OLPC's DCON chip does it. This is a
>+	 * very simple filter: for every pixel figure out which color it will be
>+	 * emitting (see the swizzling part below), sum up the corresponding color
>+	 * component of his four neighbors (up, down, left, right), add this sum to
>+	 * 4 times the value of the color component of the pixel itself, and divide all
>+	 * this by 8 to get the antialiased pixel's color component.
>+	*/
>+	
>+	for (y = y_min; y < y_max; y++) {
>+	  for (x = x_min; x < x_max; x++) {
>+	    
>+	    swizzle_position = (x + y) % 3;
>+	    sum = 0;
> 	    
>-	    switch (HostX.server_depth)
>+	    if (x > 0) {                      /* Left */
>+	      host_pixel = HostX.original_fb + ((x - 1) + y * HostX.ximg->width) * host_bpp;
>+	      sum += host_pixel[2 - swizzle_position];
>+	    }
>+	    if (x < HostX.ximg->width - 1) {  /* Right */
>+	      host_pixel = HostX.original_fb + ((x - 1) + y * HostX.ximg->width) * host_bpp;
>+	      sum += host_pixel[2 - swizzle_position];
>+	    }
>+	    if (y > 0) {                      /* Top */
>+	      host_pixel = HostX.original_fb + (x + (y - 1) * HostX.ximg->width) * host_bpp;
>+	      sum += host_pixel[2 - swizzle_position];
>+	    }
>+	    if (y < HostX.ximg->height - 1) { /* Bottom */
>+	      host_pixel = HostX.original_fb + (x + (y + 1) * HostX.ximg->width) * host_bpp;
>+	      sum += host_pixel[2 - swizzle_position];
>+	    }
>+	    
>+	    host_pixel = HostX.original_fb + (x + y * HostX.ximg->width) * host_bpp;
>+	    
>+	    aa_color = (unsigned char) ((sum + 4 * host_pixel[2 - swizzle_position]) >> 3);
>+	    
>+	    /*
>+	     * Now comes color swizzling. In the OLPC color mode, each pixel can only
>+	     * emit light of one of the three R, G, B colors. The first one is red, the
>+	     * second one (to the right) is green, etc. The second line is shifted by one
>+	     * pixel, so that the first pixel is green, the second is blue, etc. To
>+	     * reproduce this effect, figure out which color the current pixel will be
>+	     * emitting, keep the corresponding component, and discard the two others.
>+	     */
>+
>+	    r = (swizzle_position == 0)? aa_color : 0;
>+	    g = (swizzle_position == 1)? aa_color : 0;
>+	    b = (swizzle_position == 2)? aa_color : 0;
>+	    
>+	    final_host_pixel = (r << 16) | (g << 8) | (b);
>+	    
>+	    XPutPixel (HostX.ximg, x, y, final_host_pixel);	
>+	  }
>+	}
>+      } else {
>+	
>+	for (y = sy; y < sy + height; y++) {
>+	  for (x = sx; x < sx + width; x++) {
>+	    idx = (HostX.win_width * y + x) * server_bpp;
>+	    
>+	    switch (HostX.server_depth) {
>+	    case 16:
> 	      {
>-	      case 16:
>-		{
>-		  unsigned short pixel = *(unsigned short*)(HostX.fb_data+idx);
>-
>-		  r = ((pixel & 0xf800) >> 8);
>-		  g = ((pixel & 0x07e0) >> 3);
>-		  b = ((pixel & 0x001f) << 3);
>-
>-		  host_pixel = (r << 16) | (g << 8) | (b);
>-		  
>-		  XPutPixel(HostX.ximg, x, y, host_pixel);
>-		  break;
>-		}
>-	      case 8:
>-		{
>-		  unsigned char pixel = *(unsigned char*)(HostX.fb_data+idx);
>-		  XPutPixel(HostX.ximg, x, y, HostX.cmap[pixel]);
>-		  break;
>-		}
>-	      default:
>-		break;
>+	      unsigned short server_pixel = *(unsigned short*) (HostX.fb_data + idx);
>+	      XPutPixel (HostX.ximg, x, y, MAKE_24BITS_PIXEL_FROM_16BITS(server_pixel));
>+	      break;
> 	      }
>+	    case 8:
>+	      {
>+	      unsigned char server_pixel = *(unsigned char*)(HostX.fb_data + idx);
>+	      XPutPixel (HostX.ximg, x, y, HostX.cmap[server_pixel]);
>+	      break;
>+	      }
>+	    default:
>+	      break;
>+	    }
> 	  }
>+	}
>+      }
>     }
>-
>+  
>   if (HostX.have_shm)
>     {
>-      XShmPutImage(HostX.dpy, HostX.win, HostX.gc, HostX.ximg, 
>-		       sx, sy, dx, dy, width, height, False);
>+      if (swizzle)
>+	XShmPutImage (HostX.dpy, HostX.win, HostX.gc, HostX.ximg, 
>+		      x_min, y_min, x_min, y_min, x_max - x_min, y_max - y_min, False);
>+      else
>+	XShmPutImage (HostX.dpy, HostX.win, HostX.gc, HostX.ximg, 
>+		      sx, sy, dx, dy, width, height, False);
>     }
>   else
>     {
>-      XPutImage(HostX.dpy, HostX.win, HostX.gc, HostX.ximg, 
>-		sx, sy, dx, dy, width, height);
>+      if (swizzle)
>+	XPutImage (HostX.dpy, HostX.win, HostX.gc, HostX.ximg, 
>+		   x_min, y_min, x_min, y_min, x_max - x_min, y_max - y_min);
>+      else
>+	XPutImage (HostX.dpy, HostX.win, HostX.gc, HostX.ximg, 
>+		   sx, sy, dx, dy, width, height);
>     }
> 
>   XSync(HostX.dpy, False);

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