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Diffstat (limited to 'distrib/sdl-1.2.12/src/video/SDL_stretch.c')
-rw-r--r--distrib/sdl-1.2.12/src/video/SDL_stretch.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/distrib/sdl-1.2.12/src/video/SDL_stretch.c b/distrib/sdl-1.2.12/src/video/SDL_stretch.c
new file mode 100644
index 0000000..2e08c10
--- /dev/null
+++ b/distrib/sdl-1.2.12/src/video/SDL_stretch.c
@@ -0,0 +1,334 @@
+/*
+ SDL - Simple DirectMedia Layer
+ Copyright (C) 1997-2006 Sam Lantinga
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+ Sam Lantinga
+ slouken@libsdl.org
+*/
+#include "SDL_config.h"
+
+/* This a stretch blit implementation based on ideas given to me by
+ Tomasz Cejner - thanks! :)
+
+ April 27, 2000 - Sam Lantinga
+*/
+
+#include "SDL_video.h"
+#include "SDL_blit.h"
+
+/* This isn't ready for general consumption yet - it should be folded
+ into the general blitting mechanism.
+*/
+
+#if ((defined(_MFC_VER) && defined(_M_IX86)/* && !defined(_WIN32_WCE) still needed? */) || \
+ defined(__WATCOMC__) || \
+ (defined(__GNUC__) && defined(__i386__))) && SDL_ASSEMBLY_ROUTINES
+#define USE_ASM_STRETCH
+#endif
+
+#ifdef USE_ASM_STRETCH
+
+#if defined(_M_IX86) || defined(i386)
+#define PREFIX16 0x66
+#define STORE_BYTE 0xAA
+#define STORE_WORD 0xAB
+#define LOAD_BYTE 0xAC
+#define LOAD_WORD 0xAD
+#define RETURN 0xC3
+#else
+#error Need assembly opcodes for this architecture
+#endif
+
+static unsigned char copy_row[4096];
+
+static int generate_rowbytes(int src_w, int dst_w, int bpp)
+{
+ static struct {
+ int bpp;
+ int src_w;
+ int dst_w;
+ } last;
+
+ int i;
+ int pos, inc;
+ unsigned char *eip;
+ unsigned char load, store;
+
+ /* See if we need to regenerate the copy buffer */
+ if ( (src_w == last.src_w) &&
+ (dst_w == last.dst_w) && (bpp == last.bpp) ) {
+ return(0);
+ }
+ last.bpp = bpp;
+ last.src_w = src_w;
+ last.dst_w = dst_w;
+
+ switch (bpp) {
+ case 1:
+ load = LOAD_BYTE;
+ store = STORE_BYTE;
+ break;
+ case 2:
+ case 4:
+ load = LOAD_WORD;
+ store = STORE_WORD;
+ break;
+ default:
+ SDL_SetError("ASM stretch of %d bytes isn't supported\n", bpp);
+ return(-1);
+ }
+ pos = 0x10000;
+ inc = (src_w << 16) / dst_w;
+ eip = copy_row;
+ for ( i=0; i<dst_w; ++i ) {
+ while ( pos >= 0x10000L ) {
+ if ( bpp == 2 ) {
+ *eip++ = PREFIX16;
+ }
+ *eip++ = load;
+ pos -= 0x10000L;
+ }
+ if ( bpp == 2 ) {
+ *eip++ = PREFIX16;
+ }
+ *eip++ = store;
+ pos += inc;
+ }
+ *eip++ = RETURN;
+
+ /* Verify that we didn't overflow (too late) */
+ if ( eip > (copy_row+sizeof(copy_row)) ) {
+ SDL_SetError("Copy buffer overflow");
+ return(-1);
+ }
+ return(0);
+}
+
+#else
+
+#define DEFINE_COPY_ROW(name, type) \
+void name(type *src, int src_w, type *dst, int dst_w) \
+{ \
+ int i; \
+ int pos, inc; \
+ type pixel = 0; \
+ \
+ pos = 0x10000; \
+ inc = (src_w << 16) / dst_w; \
+ for ( i=dst_w; i>0; --i ) { \
+ while ( pos >= 0x10000L ) { \
+ pixel = *src++; \
+ pos -= 0x10000L; \
+ } \
+ *dst++ = pixel; \
+ pos += inc; \
+ } \
+}
+DEFINE_COPY_ROW(copy_row1, Uint8)
+DEFINE_COPY_ROW(copy_row2, Uint16)
+DEFINE_COPY_ROW(copy_row4, Uint32)
+
+#endif /* USE_ASM_STRETCH */
+
+/* The ASM code doesn't handle 24-bpp stretch blits */
+void copy_row3(Uint8 *src, int src_w, Uint8 *dst, int dst_w)
+{
+ int i;
+ int pos, inc;
+ Uint8 pixel[3] = { 0, 0, 0 };
+
+ pos = 0x10000;
+ inc = (src_w << 16) / dst_w;
+ for ( i=dst_w; i>0; --i ) {
+ while ( pos >= 0x10000L ) {
+ pixel[0] = *src++;
+ pixel[1] = *src++;
+ pixel[2] = *src++;
+ pos -= 0x10000L;
+ }
+ *dst++ = pixel[0];
+ *dst++ = pixel[1];
+ *dst++ = pixel[2];
+ pos += inc;
+ }
+}
+
+/* Perform a stretch blit between two surfaces of the same format.
+ NOTE: This function is not safe to call from multiple threads!
+*/
+int SDL_SoftStretch(SDL_Surface *src, SDL_Rect *srcrect,
+ SDL_Surface *dst, SDL_Rect *dstrect)
+{
+ int src_locked;
+ int dst_locked;
+ int pos, inc;
+ int dst_width;
+ int dst_maxrow;
+ int src_row, dst_row;
+ Uint8 *srcp = NULL;
+ Uint8 *dstp;
+ SDL_Rect full_src;
+ SDL_Rect full_dst;
+#if defined(USE_ASM_STRETCH) && defined(__GNUC__)
+ int u1, u2;
+#endif
+ const int bpp = dst->format->BytesPerPixel;
+
+ if ( src->format->BitsPerPixel != dst->format->BitsPerPixel ) {
+ SDL_SetError("Only works with same format surfaces");
+ return(-1);
+ }
+
+ /* Verify the blit rectangles */
+ if ( srcrect ) {
+ if ( (srcrect->x < 0) || (srcrect->y < 0) ||
+ ((srcrect->x+srcrect->w) > src->w) ||
+ ((srcrect->y+srcrect->h) > src->h) ) {
+ SDL_SetError("Invalid source blit rectangle");
+ return(-1);
+ }
+ } else {
+ full_src.x = 0;
+ full_src.y = 0;
+ full_src.w = src->w;
+ full_src.h = src->h;
+ srcrect = &full_src;
+ }
+ if ( dstrect ) {
+ if ( (dstrect->x < 0) || (dstrect->y < 0) ||
+ ((dstrect->x+dstrect->w) > dst->w) ||
+ ((dstrect->y+dstrect->h) > dst->h) ) {
+ SDL_SetError("Invalid destination blit rectangle");
+ return(-1);
+ }
+ } else {
+ full_dst.x = 0;
+ full_dst.y = 0;
+ full_dst.w = dst->w;
+ full_dst.h = dst->h;
+ dstrect = &full_dst;
+ }
+
+ /* Lock the destination if it's in hardware */
+ dst_locked = 0;
+ if ( SDL_MUSTLOCK(dst) ) {
+ if ( SDL_LockSurface(dst) < 0 ) {
+ SDL_SetError("Unable to lock destination surface");
+ return(-1);
+ }
+ dst_locked = 1;
+ }
+ /* Lock the source if it's in hardware */
+ src_locked = 0;
+ if ( SDL_MUSTLOCK(src) ) {
+ if ( SDL_LockSurface(src) < 0 ) {
+ if ( dst_locked ) {
+ SDL_UnlockSurface(dst);
+ }
+ SDL_SetError("Unable to lock source surface");
+ return(-1);
+ }
+ src_locked = 1;
+ }
+
+ /* Set up the data... */
+ pos = 0x10000;
+ inc = (srcrect->h << 16) / dstrect->h;
+ src_row = srcrect->y;
+ dst_row = dstrect->y;
+ dst_width = dstrect->w*bpp;
+
+#ifdef USE_ASM_STRETCH
+ /* Write the opcodes for this stretch */
+ if ( (bpp != 3) &&
+ (generate_rowbytes(srcrect->w, dstrect->w, bpp) < 0) ) {
+ return(-1);
+ }
+#endif
+
+ /* Perform the stretch blit */
+ for ( dst_maxrow = dst_row+dstrect->h; dst_row<dst_maxrow; ++dst_row ) {
+ dstp = (Uint8 *)dst->pixels + (dst_row*dst->pitch)
+ + (dstrect->x*bpp);
+ while ( pos >= 0x10000L ) {
+ srcp = (Uint8 *)src->pixels + (src_row*src->pitch)
+ + (srcrect->x*bpp);
+ ++src_row;
+ pos -= 0x10000L;
+ }
+#ifdef USE_ASM_STRETCH
+ switch (bpp) {
+ case 3:
+ copy_row3(srcp, srcrect->w, dstp, dstrect->w);
+ break;
+ default:
+#ifdef __GNUC__
+ __asm__ __volatile__ (
+ "call *%4"
+ : "=&D" (u1), "=&S" (u2)
+ : "0" (dstp), "1" (srcp), "r" (copy_row)
+ : "memory" );
+#elif defined(_MSC_VER) || defined(__WATCOMC__)
+ { void *code = copy_row;
+ __asm {
+ push edi
+ push esi
+
+ mov edi, dstp
+ mov esi, srcp
+ call dword ptr code
+
+ pop esi
+ pop edi
+ }
+ }
+#else
+#error Need inline assembly for this compiler
+#endif
+ break;
+ }
+#else
+ switch (bpp) {
+ case 1:
+ copy_row1(srcp, srcrect->w, dstp, dstrect->w);
+ break;
+ case 2:
+ copy_row2((Uint16 *)srcp, srcrect->w,
+ (Uint16 *)dstp, dstrect->w);
+ break;
+ case 3:
+ copy_row3(srcp, srcrect->w, dstp, dstrect->w);
+ break;
+ case 4:
+ copy_row4((Uint32 *)srcp, srcrect->w,
+ (Uint32 *)dstp, dstrect->w);
+ break;
+ }
+#endif
+ pos += inc;
+ }
+
+ /* We need to unlock the surfaces if they're locked */
+ if ( dst_locked ) {
+ SDL_UnlockSurface(dst);
+ }
+ if ( src_locked ) {
+ SDL_UnlockSurface(src);
+ }
+ return(0);
+}
+
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