Stefano Stabellini | c18a2c3 | 2009-06-24 11:58:25 +0100 | [diff] [blame] | 1 | /* |
| 2 | * SDL_zoom - surface scaling |
| 3 | * |
| 4 | * Copyright (c) 2009 Citrix Systems, Inc. |
| 5 | * |
| 6 | * Derived from: SDL_rotozoom, LGPL (c) A. Schiffler from the SDL_gfx library. |
| 7 | * Modifications by Stefano Stabellini. |
| 8 | * |
| 9 | * This work is licensed under the terms of the GNU GPL version 2. |
| 10 | * See the COPYING file in the top-level directory. |
| 11 | * |
| 12 | */ |
| 13 | |
| 14 | #include "sdl_zoom.h" |
Paolo Bonzini | 1de7afc | 2012-12-17 18:20:00 +0100 | [diff] [blame] | 15 | #include "qemu/osdep.h" |
Stefano Stabellini | c18a2c3 | 2009-06-24 11:58:25 +0100 | [diff] [blame] | 16 | #include <stdint.h> |
Blue Swirl | 22d091b | 2009-07-01 18:49:34 +0000 | [diff] [blame] | 17 | #include <stdio.h> |
Stefano Stabellini | c18a2c3 | 2009-06-24 11:58:25 +0100 | [diff] [blame] | 18 | |
| 19 | static int sdl_zoom_rgb16(SDL_Surface *src, SDL_Surface *dst, int smooth, |
| 20 | SDL_Rect *dst_rect); |
| 21 | static int sdl_zoom_rgb32(SDL_Surface *src, SDL_Surface *dst, int smooth, |
| 22 | SDL_Rect *dst_rect); |
| 23 | |
| 24 | #define BPP 32 |
| 25 | #include "sdl_zoom_template.h" |
| 26 | #undef BPP |
| 27 | #define BPP 16 |
| 28 | #include "sdl_zoom_template.h" |
| 29 | #undef BPP |
| 30 | |
| 31 | int sdl_zoom_blit(SDL_Surface *src_sfc, SDL_Surface *dst_sfc, int smooth, |
| 32 | SDL_Rect *in_rect) |
| 33 | { |
| 34 | SDL_Rect zoom, src_rect; |
| 35 | int extra; |
| 36 | |
| 37 | /* Grow the size of the modified rectangle to avoid edge artefacts */ |
| 38 | src_rect.x = (in_rect->x > 0) ? (in_rect->x - 1) : 0; |
| 39 | src_rect.y = (in_rect->y > 0) ? (in_rect->y - 1) : 0; |
| 40 | |
| 41 | src_rect.w = in_rect->w + 1; |
| 42 | if (src_rect.x + src_rect.w > src_sfc->w) |
| 43 | src_rect.w = src_sfc->w - src_rect.x; |
| 44 | |
| 45 | src_rect.h = in_rect->h + 1; |
| 46 | if (src_rect.y + src_rect.h > src_sfc->h) |
| 47 | src_rect.h = src_sfc->h - src_rect.y; |
| 48 | |
| 49 | /* (x,y) : round down */ |
| 50 | zoom.x = (int)(((float)(src_rect.x * dst_sfc->w)) / (float)(src_sfc->w)); |
| 51 | zoom.y = (int)(((float)(src_rect.y * dst_sfc->h)) / (float)(src_sfc->h)); |
| 52 | |
| 53 | /* (w,h) : round up */ |
| 54 | zoom.w = (int)( ((double)((src_rect.w * dst_sfc->w) + (src_sfc->w - 1))) / |
| 55 | (double)(src_sfc->w)); |
| 56 | |
| 57 | zoom.h = (int)( ((double)((src_rect.h * dst_sfc->h) + (src_sfc->h - 1))) / |
| 58 | (double)(src_sfc->h)); |
| 59 | |
| 60 | /* Account for any (x,y) rounding by adding one-source-pixel's worth |
| 61 | * of destination pixels and then edge checking. |
| 62 | */ |
| 63 | |
| 64 | extra = ((dst_sfc->w-1) / src_sfc->w) + 1; |
| 65 | |
| 66 | if ((zoom.x + zoom.w) < (dst_sfc->w - extra)) |
| 67 | zoom.w += extra; |
| 68 | else |
| 69 | zoom.w = dst_sfc->w - zoom.x; |
| 70 | |
| 71 | extra = ((dst_sfc->h-1) / src_sfc->h) + 1; |
| 72 | |
| 73 | if ((zoom.y + zoom.h) < (dst_sfc->h - extra)) |
| 74 | zoom.h += extra; |
| 75 | else |
| 76 | zoom.h = dst_sfc->h - zoom.y; |
| 77 | |
| 78 | /* The rectangle (zoom.x, zoom.y, zoom.w, zoom.h) is the area on the |
| 79 | * destination surface that needs to be updated. |
| 80 | */ |
| 81 | if (src_sfc->format->BitsPerPixel == 32) |
| 82 | sdl_zoom_rgb32(src_sfc, dst_sfc, smooth, &zoom); |
| 83 | else if (src_sfc->format->BitsPerPixel == 16) |
| 84 | sdl_zoom_rgb16(src_sfc, dst_sfc, smooth, &zoom); |
| 85 | else { |
| 86 | fprintf(stderr, "pixel format not supported\n"); |
| 87 | return -1; |
| 88 | } |
| 89 | |
| 90 | /* Return the rectangle of the update to the caller */ |
| 91 | *in_rect = zoom; |
| 92 | |
| 93 | return 0; |
| 94 | } |
| 95 | |