| 1 | \r |
| 2 | // This file is part of the PicoDrive Megadrive Emulator\r |
| 3 | \r |
| 4 | // Copyright (c) 2011 FinalDave (emudave (at) gmail.com)\r |
| 5 | \r |
| 6 | // This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r |
| 7 | // You can choose the license that has the most advantages for you.\r |
| 8 | \r |
| 9 | // SVN repository can be found at http://code.google.com/p/cyclone68000/\r |
| 10 | \r |
| 11 | #include "PicoInt.h"\r |
| 12 | \r |
| 13 | int PicuAnd=0xf7de;\r |
| 14 | \r |
| 15 | // Quick low-quality conversion of 320 to 176:\r |
| 16 | int PicuQuick(unsigned short *dest,unsigned short *src)\r |
| 17 | {\r |
| 18 | unsigned short *end=NULL;\r |
| 19 | \r |
| 20 | src+=13; end=src+290;\r |
| 21 | dest++;\r |
| 22 | \r |
| 23 | do\r |
| 24 | {\r |
| 25 | *dest++=*src++;\r |
| 26 | *dest++=*src; src+=2;\r |
| 27 | *dest++=*src; src+=2;\r |
| 28 | *dest++=*src++;\r |
| 29 | *dest++=*src; src+=2;\r |
| 30 | *dest++=*src; src+=2;\r |
| 31 | }\r |
| 32 | while (src<end);\r |
| 33 | \r |
| 34 | return 0;\r |
| 35 | }\r |
| 36 | \r |
| 37 | // Shrink the pixels in src/srcLen, to the screen line pointed to by dest/destLen\r |
| 38 | int PicuShrink(unsigned short *dest,int destLen,unsigned short *src,int srcLen)\r |
| 39 | {\r |
| 40 | unsigned short *end=NULL;\r |
| 41 | int bias=0,pa=0,sub=0;\r |
| 42 | \r |
| 43 | end=dest+destLen;\r |
| 44 | sub=srcLen-destLen;\r |
| 45 | \r |
| 46 | do\r |
| 47 | {\r |
| 48 | pa=*src++; bias-=sub;\r |
| 49 | if (bias<0) { pa+=*src++; pa>>=1; bias+=destLen; }\r |
| 50 | *dest++=(unsigned short)pa;\r |
| 51 | \r |
| 52 | pa=*src++; bias-=sub;\r |
| 53 | if (bias<0) { pa+=*src++; pa>>=1; bias+=destLen; }\r |
| 54 | *dest++=(unsigned short)pa;\r |
| 55 | }\r |
| 56 | while (dest<end);\r |
| 57 | \r |
| 58 | return 0;\r |
| 59 | }\r |
| 60 | \r |
| 61 | int PicuMerge(unsigned short *dest,int destLen,unsigned short *src,int srcLen)\r |
| 62 | {\r |
| 63 | unsigned short *end=NULL;\r |
| 64 | int bias=0,pa=0,mask=PicuAnd,sub=0;\r |
| 65 | \r |
| 66 | end=dest+destLen;\r |
| 67 | sub=srcLen-destLen;\r |
| 68 | \r |
| 69 | do\r |
| 70 | {\r |
| 71 | pa=*src++; bias-=sub;\r |
| 72 | if (bias<0) { pa+=*src++; pa>>=1; bias+=destLen; }\r |
| 73 | pa&=mask; pa+=(*dest)&mask; pa>>=1;\r |
| 74 | *dest++=(unsigned short)pa;\r |
| 75 | \r |
| 76 | pa=*src++; bias-=sub;\r |
| 77 | if (bias<0) { pa+=*src++; pa>>=1; bias+=destLen; }\r |
| 78 | pa&=mask; pa+=(*dest)&mask; pa>>=1;\r |
| 79 | *dest++=(unsigned short)pa;\r |
| 80 | }\r |
| 81 | while (dest<end);\r |
| 82 | \r |
| 83 | return 0;\r |
| 84 | }\r |
| 85 | \r |