mirror of https://github.com/GNOME/gimp.git
implement bresenham-like stepping for interpolating the view in
2007-09-23 Simon Budig <simon@gimp.org> * app/display/gimpdisplayshell-render.c: implement bresenham-like stepping for interpolating the view in x-direction. Since I now know how it is supposed to work the y direction will follow shortly. Adresses bug #474509. svn path=/trunk/; revision=23617
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Simon Budig
Simon Budig
parent
cd5a441610
commit
40f66e9c13
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@ -1,3 +1,12 @@
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2007-09-23 Simon Budig <simon@gimp.org>
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* app/display/gimpdisplayshell-render.c: implement
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bresenham-like stepping for interpolating the view in
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x-direction. Since I now know how it is supposed to work
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the y direction will follow shortly.
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Adresses bug #474509.
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2007-09-22 Martin Nordholts <martinn@svn.gnome.org>
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* app/tools/gimpcropoptions.[ch]: Add an allow-growing option.
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@ -78,8 +78,11 @@ struct _RenderInfo
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gint dest_bpp;
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gint dest_bpl;
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gint dest_width;
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gint xstart;
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gint xdelta;
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/* Bresenham helpers */
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gint x_dest_inc; /* amount to increment for each dest. pixel */
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gint x_src_dec; /* amount to decrement for each source pixel */
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gint dx_start; /* pixel fraction for first pixel */
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gint yfraction;
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};
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@ -874,22 +877,20 @@ gimp_display_shell_render_info_scale (RenderInfo *info,
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/* We must reset info->dest because this member is modified in render
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* functions.
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*/
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info->dest = shell->render_buf;
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info->dest = shell->render_buf;
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info->scalex = scale_x;
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info->scaley = scale_y;
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info->scalex = scale_x;
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info->scaley = scale_y;
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info->src_x = (gdouble) info->x / info->scalex;
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info->src_y = (gdouble) info->y / info->scaley;
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info->src_y = (gdouble) info->y / info->scaley;
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info->xdelta = (1 << 16) * (1.0 / info->scalex);
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info->xstart = (gdouble) info->x / info->scalex * 65536.0;
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/* use Bresenham like stepping */
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info->x_dest_inc = tile_manager_width (src_tiles);
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info->x_src_dec = ceil (tile_manager_width (src_tiles) * info->scalex);
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/* avoid aliasing errors when zooming in */
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if (info->scalex > 1)
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{
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info->xstart += info->xdelta / 2;
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}
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info->dx_start = info->x_dest_inc * info->x + info->x_dest_inc/2;
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info->src_x = info->dx_start / info->x_src_dec;
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info->dx_start = info->dx_start % info->x_src_dec;
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}
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static const guint *
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@ -1048,14 +1049,13 @@ render_image_tile_fault (RenderInfo *info)
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sample pair */
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gint tilexL; /* the current x-tile indice used for the left
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sample pair */
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gint xdelta; /* fixed point amount to increment source x
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coordinas for each horizontal integer destination
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pixel increment */
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gint bpp;
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glong x;
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gint dx;
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gint src_x;
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gint skipped;
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gint footprint_x;
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gint footprint_y;
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guint footprint_x;
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guint footprint_y;
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guint foosum;
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guint left_weight;
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@ -1109,7 +1109,7 @@ render_image_tile_fault (RenderInfo *info)
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}
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footprint_y = (1.0 / info->scaley) * 256;
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footprint_x = (1.0 / info->scalex) * 256;
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footprint_x = info->x_src_dec;
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foosum = footprint_x * footprint_y;
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@ -1240,7 +1240,8 @@ render_image_tile_fault (RenderInfo *info)
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bpp = tile_manager_bpp (info->src_tiles);
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dest = tile_buf;
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x = info->xstart;
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dx = info->dx_start;
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src_x = info->src_x;
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width = info->w;
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@ -1248,53 +1249,38 @@ render_image_tile_fault (RenderInfo *info)
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tilex1 = (info->src_x + 1) / TILE_WIDTH;
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tilexL = (info->src_x - 1) / TILE_WIDTH;
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xdelta = info->xdelta;
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do
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{
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gint src_x = x >> 16;
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gint skipped;
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/* we're dealing with unsigneds here, be extra careful */
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left_weight = MAX (footprint_x / 2, dx) - dx;
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right_weight = MAX (dx, footprint_x / 2) - footprint_x / 2;
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center_weight = footprint_x - left_weight - right_weight;
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{
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gint dx = (x >> 8) & 0xff;
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if (dx > footprint_x / 2)
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left_weight = 0;
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else
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left_weight = footprint_x / 2 - dx;
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if (0xff - dx > footprint_x / 2)
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right_weight = 0;
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else
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right_weight = footprint_x / 2 - (0xff - dx);
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center_weight = footprint_x - left_weight - right_weight;
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if (src_x + 1 >= source_width)
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if (src_x + 1 >= source_width)
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{
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src[2]=src[1];
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src[5]=src[4];
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src[8]=src[7];
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}
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if (info->src_y + 1 >= source_height)
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if (info->src_y + 1 >= source_height)
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{
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src[6]=src[3];
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src[7]=src[4];
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src[8]=src[5];
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}
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box_filter (left_weight, center_weight, right_weight,
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top_weight, middle_weight, bottom_weight, foosum,
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src, dest, bpp);
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}
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box_filter (left_weight, center_weight, right_weight,
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top_weight, middle_weight, bottom_weight, foosum,
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src, dest, bpp);
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dest += bpp;
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x += xdelta;
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skipped = (x >> 16) - src_x;
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dx += info->x_dest_inc;
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skipped = dx / info->x_src_dec;
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if (skipped)
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{
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dx -= skipped * info->x_src_dec;
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/* if we changed integer source pixel coordinates in the source
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* buffer, make sure the src pointers (and their backing tiles) are
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* correct
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@ -1496,9 +1482,9 @@ render_image_tile_fault (RenderInfo *info)
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while (--width);
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done:
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for (x = 0; x < 9; x++)
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if (tile[x])
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tile_release (tile[x], FALSE);
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for (dx = 0; dx < 9; dx++)
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if (tile[dx])
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tile_release (tile[dx], FALSE);
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return tile_buf;
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}
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@ -1512,9 +1498,9 @@ render_image_tile_fault_nearest (RenderInfo *info)
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guchar *dest;
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gint width;
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gint tilex;
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gint xdelta;
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gint bpp;
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glong x;
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gint src_x;
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gint dx;
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tile = tile_manager_get_tile (info->src_tiles,
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info->src_x, info->src_y, TRUE, FALSE);
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@ -1526,18 +1512,16 @@ render_image_tile_fault_nearest (RenderInfo *info)
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bpp = tile_manager_bpp (info->src_tiles);
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dest = tile_buf;
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x = info->xstart;
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dx = info->dx_start;
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width = info->w;
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src_x = info->src_x;
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tilex = info->src_x / TILE_WIDTH;
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xdelta = info->xdelta;
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do
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{
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const guchar *s = src;
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gint src_x = x >> 16;
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gint skipped;
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switch (bpp)
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@ -1552,14 +1536,14 @@ render_image_tile_fault_nearest (RenderInfo *info)
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*dest++ = *s++;
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}
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x += xdelta;
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skipped = (x >> 16) - src_x;
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dx += info->x_dest_inc;
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skipped = dx / info->x_src_dec;
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if (skipped)
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{
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src += skipped * bpp;
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src_x += skipped;
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dx -= skipped * info->x_src_dec;
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if ((src_x / TILE_WIDTH) != tilex)
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{
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@ -1601,11 +1585,10 @@ render_image_tile_fault_one_row (RenderInfo *info)
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sample pair */
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gint tilexL; /* the current x-tile indice used for the left
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sample pair */
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gint xdelta; /* fixed point amount to increment source x
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coordinas for each horizontal integer destination
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pixel increment */
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gint bpp;
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glong x;
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gint dx;
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gint src_x;
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gint skipped;
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guint footprint_x;
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guint footprint_y;
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@ -1624,7 +1607,7 @@ render_image_tile_fault_one_row (RenderInfo *info)
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source_width = tile_manager_width (info->src_tiles);
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footprint_y = (1.0/info->scaley) * 256;
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footprint_x = (1.0/info->scalex) * 256;
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footprint_x = info->x_src_dec;
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foosum = footprint_x * footprint_y;
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{
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@ -1709,7 +1692,8 @@ render_image_tile_fault_one_row (RenderInfo *info)
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bpp = tile_manager_bpp (info->src_tiles);
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dest = tile_buf;
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x = info->xstart;
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dx = info->dx_start;
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src_x = info->src_x;
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width = info->w;
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@ -1717,47 +1701,31 @@ render_image_tile_fault_one_row (RenderInfo *info)
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tilex1 = (info->src_x + 1) / TILE_WIDTH;
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tilexL = (info->src_x - 1) / TILE_WIDTH;
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xdelta = info->xdelta;
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do
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{
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gint src_x = x >> 16;
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gint skipped;
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left_weight = MAX (footprint_x / 2, dx) - dx;
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right_weight = MAX (dx, footprint_x / 2) - footprint_x / 2;
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center_weight = footprint_x - left_weight - right_weight;
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{
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gint dx = (x >> 8) & 0xff;
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if (dx > footprint_x / 2)
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left_weight = 0;
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else
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left_weight = footprint_x / 2 - dx;
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if (0xff - dx > footprint_x / 2)
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right_weight = 0;
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else
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right_weight = footprint_x / 2 - (0xff - dx);
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center_weight = footprint_x - left_weight - right_weight;
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if (src_x + 1 >= source_width)
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{
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src[2]=src[1];
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src[5]=src[4];
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src[8]=src[7];
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}
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box_filter (left_weight, center_weight, right_weight,
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top_weight, middle_weight, bottom_weight, foosum,
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src, dest, bpp);
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}
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if (src_x + 1 >= source_width)
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{
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src[2]=src[1];
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src[5]=src[4];
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src[8]=src[7];
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}
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box_filter (left_weight, center_weight, right_weight,
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top_weight, middle_weight, bottom_weight, foosum,
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src, dest, bpp);
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dest += bpp;
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x += xdelta;
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skipped = (x >> 16) - src_x;
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dx += info->x_dest_inc;
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skipped = dx / info->x_src_dec;
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if (skipped)
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{
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dx -= skipped * info->x_src_dec;
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/* if we changed integer source pixel coordinates in the source
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* buffer, make sure the src pointers (and their backing tiles) are
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* correct
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@ -1880,9 +1848,9 @@ render_image_tile_fault_one_row (RenderInfo *info)
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while (--width);
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done:
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for (x=0; x<3; x++)
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if (tile[x])
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tile_release (tile[x], FALSE);
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for (dx=0; dx<3; dx++)
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if (tile[dx])
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tile_release (tile[dx], FALSE);
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return tile_buf;
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}
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