| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org> |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| #include "../SDL_internal.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(_MSC_VER) && defined(_M_IX86)) || \ |
| (defined(__WATCOMC__) && defined(__386__)) || \ |
| (defined(__GNUC__) && defined(__i386__))) && SDL_ASSEMBLY_ROUTINES |
| /* There's a bug with gcc 4.4.1 and -O2 where srcp doesn't get the correct |
| * value after the first scanline. FIXME? */ |
| /* #define USE_ASM_STRETCH */ |
| #endif |
| |
| #ifdef USE_ASM_STRETCH |
| |
| #ifdef HAVE_MPROTECT |
| #include <sys/types.h> |
| #include <sys/mman.h> |
| #endif |
| #ifdef __GNUC__ |
| #define PAGE_ALIGNED __attribute__((__aligned__(4096))) |
| #else |
| #define PAGE_ALIGNED |
| #endif |
| |
| #if defined(_M_IX86) || defined(__i386__) || defined(__386__) |
| #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] PAGE_ALIGNED; |
| |
| static int |
| generate_rowbytes(int src_w, int dst_w, int bpp) |
| { |
| static struct |
| { |
| int bpp; |
| int src_w; |
| int dst_w; |
| int status; |
| } last; |
| |
| int i; |
| int pos, inc; |
| unsigned char *eip, *fence; |
| 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 (last.status); |
| } |
| last.bpp = bpp; |
| last.src_w = src_w; |
| last.dst_w = dst_w; |
| last.status = -1; |
| |
| switch (bpp) { |
| case 1: |
| load = LOAD_BYTE; |
| store = STORE_BYTE; |
| break; |
| case 2: |
| case 4: |
| load = LOAD_WORD; |
| store = STORE_WORD; |
| break; |
| default: |
| return SDL_SetError("ASM stretch of %d bytes isn't supported", bpp); |
| } |
| #ifdef HAVE_MPROTECT |
| /* Make the code writeable */ |
| if (mprotect(copy_row, sizeof(copy_row), PROT_READ | PROT_WRITE) < 0) { |
| return SDL_SetError("Couldn't make copy buffer writeable"); |
| } |
| #endif |
| pos = 0x10000; |
| inc = (src_w << 16) / dst_w; |
| eip = copy_row; |
| fence = copy_row + sizeof(copy_row)-2; |
| for (i = 0; i < dst_w; ++i) { |
| while (pos >= 0x10000L) { |
| if (eip == fence) { |
| return -1; |
| } |
| if (bpp == 2) { |
| *eip++ = PREFIX16; |
| } |
| *eip++ = load; |
| pos -= 0x10000L; |
| } |
| if (eip == fence) { |
| return -1; |
| } |
| if (bpp == 2) { |
| *eip++ = PREFIX16; |
| } |
| *eip++ = store; |
| pos += inc; |
| } |
| *eip++ = RETURN; |
| |
| #ifdef HAVE_MPROTECT |
| /* Make the code executable but not writeable */ |
| if (mprotect(copy_row, sizeof(copy_row), PROT_READ | PROT_EXEC) < 0) { |
| return SDL_SetError("Couldn't make copy buffer executable"); |
| } |
| #endif |
| last.status = 0; |
| return (0); |
| } |
| |
| #endif /* USE_ASM_STRETCH */ |
| |
| #define DEFINE_COPY_ROW(name, type) \ |
| static 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; \ |
| } \ |
| } |
| /* *INDENT-OFF* */ |
| DEFINE_COPY_ROW(copy_row1, Uint8) |
| DEFINE_COPY_ROW(copy_row2, Uint16) |
| DEFINE_COPY_ROW(copy_row4, Uint32) |
| /* *INDENT-ON* */ |
| |
| /* The ASM code doesn't handle 24-bpp stretch blits */ |
| static 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, const SDL_Rect * srcrect, |
| SDL_Surface * dst, const SDL_Rect * dstrect) |
| { |
| int src_locked; |
| int dst_locked; |
| int pos, inc; |
| int dst_maxrow; |
| int src_row, dst_row; |
| Uint8 *srcp = NULL; |
| Uint8 *dstp; |
| SDL_Rect full_src; |
| SDL_Rect full_dst; |
| #ifdef USE_ASM_STRETCH |
| SDL_bool use_asm = SDL_TRUE; |
| #ifdef __GNUC__ |
| int u1, u2; |
| #endif |
| #endif /* USE_ASM_STRETCH */ |
| const int bpp = dst->format->BytesPerPixel; |
| |
| if (src->format->format != dst->format->format) { |
| return SDL_SetError("Only works with same format surfaces"); |
| } |
| |
| /* 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)) { |
| return SDL_SetError("Invalid source blit rectangle"); |
| } |
| } 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)) { |
| return SDL_SetError("Invalid destination blit rectangle"); |
| } |
| } 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) { |
| return SDL_SetError("Unable to lock destination surface"); |
| } |
| 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); |
| } |
| return SDL_SetError("Unable to lock source surface"); |
| } |
| src_locked = 1; |
| } |
| |
| /* Set up the data... */ |
| pos = 0x10000; |
| inc = (srcrect->h << 16) / dstrect->h; |
| src_row = srcrect->y; |
| dst_row = dstrect->y; |
| |
| #ifdef USE_ASM_STRETCH |
| /* Write the opcodes for this stretch */ |
| if ((bpp == 3) || (generate_rowbytes(srcrect->w, dstrect->w, bpp) < 0)) { |
| use_asm = SDL_FALSE; |
| } |
| #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 |
| if (use_asm) { |
| #ifdef __GNUC__ |
| __asm__ __volatile__("call *%4":"=&D"(u1), "=&S"(u2) |
| :"0"(dstp), "1"(srcp), "r"(copy_row) |
| :"memory"); |
| #elif defined(_MSC_VER) || defined(__WATCOMC__) |
| /* *INDENT-OFF* */ |
| { |
| void *code = copy_row; |
| __asm { |
| push edi |
| push esi |
| mov edi, dstp |
| mov esi, srcp |
| call dword ptr code |
| pop esi |
| pop edi |
| } |
| } |
| /* *INDENT-ON* */ |
| #else |
| #error Need inline assembly for this compiler |
| #endif |
| } else |
| #endif |
| 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; |
| } |
| 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); |
| } |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |