SDL  2.0
SDL_blit_copy.c
Go to the documentation of this file.
1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../SDL_internal.h"
22 
23 #include "SDL_video.h"
24 #include "SDL_blit.h"
25 #include "SDL_blit_copy.h"
26 
27 
28 #ifdef __SSE__
29 /* This assumes 16-byte aligned src and dst */
30 static SDL_INLINE void
31 SDL_memcpySSE(Uint8 * dst, const Uint8 * src, int len)
32 {
33  int i;
34 
35  __m128 values[4];
36  for (i = len / 64; i--;) {
37  _mm_prefetch(src, _MM_HINT_NTA);
38  values[0] = *(__m128 *) (src + 0);
39  values[1] = *(__m128 *) (src + 16);
40  values[2] = *(__m128 *) (src + 32);
41  values[3] = *(__m128 *) (src + 48);
42  _mm_stream_ps((float *) (dst + 0), values[0]);
43  _mm_stream_ps((float *) (dst + 16), values[1]);
44  _mm_stream_ps((float *) (dst + 32), values[2]);
45  _mm_stream_ps((float *) (dst + 48), values[3]);
46  src += 64;
47  dst += 64;
48  }
49 
50  if (len & 63)
51  SDL_memcpy(dst, src, len & 63);
52 }
53 #endif /* __SSE__ */
54 
55 #ifdef __MMX__
56 #ifdef _MSC_VER
57 #pragma warning(disable:4799)
58 #endif
59 static SDL_INLINE void
60 SDL_memcpyMMX(Uint8 * dst, const Uint8 * src, int len)
61 {
62  const int remain = (len & 63);
63  int i;
64 
65  __m64* d64 = (__m64*)dst;
66  __m64* s64 = (__m64*)src;
67 
68  for(i= len / 64; i--;) {
69  d64[0] = s64[0];
70  d64[1] = s64[1];
71  d64[2] = s64[2];
72  d64[3] = s64[3];
73  d64[4] = s64[4];
74  d64[5] = s64[5];
75  d64[6] = s64[6];
76  d64[7] = s64[7];
77 
78  d64 += 8;
79  s64 += 8;
80  }
81 
82  if (remain)
83  {
84  const int skip = len - remain;
85  SDL_memcpy(dst + skip, src + skip, remain);
86  }
87 }
88 #endif /* __MMX__ */
89 
90 void
92 {
93  SDL_bool overlap;
94  Uint8 *src, *dst;
95  int w, h;
96  int srcskip, dstskip;
97 
98  w = info->dst_w * info->dst_fmt->BytesPerPixel;
99  h = info->dst_h;
100  src = info->src;
101  dst = info->dst;
102  srcskip = info->src_pitch;
103  dstskip = info->dst_pitch;
104 
105  /* Properly handle overlapping blits */
106  if (src < dst) {
107  overlap = (dst < (src + h*srcskip));
108  } else {
109  overlap = (src < (dst + h*dstskip));
110  }
111  if (overlap) {
112  if ( dst < src ) {
113  while ( h-- ) {
114  SDL_memmove(dst, src, w);
115  src += srcskip;
116  dst += dstskip;
117  }
118  } else {
119  src += ((h-1) * srcskip);
120  dst += ((h-1) * dstskip);
121  while ( h-- ) {
122  SDL_memmove(dst, src, w);
123  src -= srcskip;
124  dst -= dstskip;
125  }
126  }
127  return;
128  }
129 
130 #ifdef __SSE__
131  if (SDL_HasSSE() &&
132  !((uintptr_t) src & 15) && !(srcskip & 15) &&
133  !((uintptr_t) dst & 15) && !(dstskip & 15)) {
134  while (h--) {
135  SDL_memcpySSE(dst, src, w);
136  src += srcskip;
137  dst += dstskip;
138  }
139  return;
140  }
141 #endif
142 
143 #ifdef __MMX__
144  if (SDL_HasMMX() && !(srcskip & 7) && !(dstskip & 7)) {
145  while (h--) {
146  SDL_memcpyMMX(dst, src, w);
147  src += srcskip;
148  dst += dstskip;
149  }
150  _mm_empty();
151  return;
152  }
153 #endif
154 
155  while (h--) {
156  SDL_memcpy(dst, src, w);
157  src += srcskip;
158  dst += dstskip;
159  }
160 }
161 
162 /* vi: set ts=4 sw=4 expandtab: */
GLenum GLenum dst
Uint8 BytesPerPixel
Definition: SDL_pixels.h:320
GLfloat GLfloat GLfloat GLfloat h
int dst_pitch
Definition: SDL_blit.h:63
GLenum src
GLenum GLsizei len
GLenum GLsizei GLsizei GLint * values
Uint8 * dst
Definition: SDL_blit.h:61
#define SDL_memcpy
void SDL_BlitCopy(SDL_BlitInfo *info)
Definition: SDL_blit_copy.c:91
uint8_t Uint8
Definition: SDL_stdinc.h:157
GLubyte GLubyte GLubyte GLubyte w
unsigned int uintptr_t
#define SDL_memmove
#define SDL_HasMMX
Uint8 * src
Definition: SDL_blit.h:57
SDL_PixelFormat * dst_fmt
Definition: SDL_blit.h:66
int src_pitch
Definition: SDL_blit.h:59
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:50
SDL_bool
Definition: SDL_stdinc.h:139
#define SDL_INLINE
Definition: begin_code.h:131
#define SDL_HasSSE