Rotozoomer for SDL surfaces.
[ SDL_rotozoom-1.6.tar.gz (206k)]
Author: A. Schiffler,
aschiffler @ ferzkopp.net to contact the author.
Licenced under the LGPL, see the file LICENSE in the archive for details.
Rotozoom/Zoom function for SDL ======================================================================================== (C) LGPL, A. Schiffler, aschiffler@sympatico.ca - see LICENSE for details. INTERFACE --------- SDL_Surface * rotozoomSurface (SDL_Surface *src, double angle, double zoom, int smooth); Rotates and zoomes a 32bit or 8bit 'src' surface to newly created 'dst' surface. 'angle' is the rotation in degrees. 'zoom' a scaling factor. If 'smooth' is 1 then the destination 32bit surface is anti-aliased. If the surface is not 8bit or 32bit RGBA/ABGR it will be converted into a 32bit RGBA format on the fly. SDL_Surface * zoomSurface (SDL_Surface *src, double zoomx, double zoomy, int smooth); Zoomes a 32bit or 8bit 'src' surface to newly created 'dst' surface. 'zoomx' and 'zoomy' are scaling factors for width and height. If 'smooth' is 1 then the destination 32bit surface is anti-aliased. If the surface is not 8bit or 32bit RGBA/ABGR it will be converted into a 32bit RGBA format on the fly. Smoothing (interpolation) flags work only on 32bit surfaces: #define SMOOTHING_OFF 0 #define SMOOTHING_ON 1 EXAMPLE ------- Run ./configure make Test with ./testrotozoom Check out the testrotozoom.c code for how to preprocess non-32bit surfaces for better speed. Unzip VisualC.zip for VC projects files. CHANGES ------- Ver 1.6 - Mon Nov 19 21:19:26 EST 2001 * Added interpolation to alpha channel (simplifies code) * Ran the sourcecode through 'indent' for better readability Ver 1.5 - Sat Jul 7 13:02:07 EDT 2001 * Added project files (VisualC.zip) and modifications for VC project building. * Fixed old versioning in configure.in file. * Fixed LICENSE file and LGPL source reference. Ver 1.4 - Mon Jun 4 12:15:31 EDT 2001 * Removed SDL_SoftStretch call again in favour of an internal zoom routine. * Added new zoomSurface() function with seperate X and Y zoom factors. Ver 1.3 - Thu May 31 08:37:36 EDT 2001 * Modified code to handle RGBA or ABGR source surfaces transparently. * More error checking, source surface locking. * Slighly expanded test program with event handling. Ver 1.2 - Wed May 30 18:18:05 EDT 2001 * Fixed the completely broken 32bit routine's pointer arithmetic. * Uses SDL_SoftStretch in certain cases (angle=0, smooth=0). * Convert source surface on the fly if not 8/32bit. * Added license file - was empty before (duh). Ver 1.1 - Wed May 23 15:04:42 EDT 2001 * Added automake/autoconf scripts and testprogram. Ver 1.0 - Fri Mar 16 08:16:06 EST 2001 * Initial release COMMENTS -------- SDL_rotozoom was designed to work with SDL Ver. 1.2 and higher - see http://www.libsdl.org for more info in the SDL library. The code is not super optimal - but it should be fast enough even for some realtime effects if the bitmaps are kept small. The routines are mostly ment to be used for pre-rendering stuff in higher quality (i.e. smoothing) - that's also a reason why the API differs from SDL_BlitRect() and creates new target surfaces. The final rendering speed is dependent on the target surface size as as it is beeing xy-scanned when rendering. Note also that the smoothing toggle is dependent on the input surface bit depth. 8bit surfaces will never be smoothed - only 32bit surfaces will. CONTRIBUTORS ------------ * VisualC project files and fixes from Giorgio Delmondo, giorgio@hurd.it - thanks Giorgio.