x86_ctv.asm

   1 ; CTV!
   2
   3 bits 32
   4 section .text
   5 ;extern "C" int blur_bitmap_16
   6 ;  (unsigned char *dest,int len);
   7
   8 global blur_bitmap_16
   9 global test_ctv
  10 times ($$-$) & 3 db 0
  11 blur_bitmap_16:
  12 push edi ; point to screen
  13 push edx ; temporary for unwrapping
  14 push ecx ; count
  15 push ebx ; last pixel
  16
  17 ; ax = current pixel
  18
  19 xor ebx,ebx ; Last pixel
  20
  21 mov edi,[esp+20] ; edi is a pointer to the bitmap
  22 mov ecx,[esp+24] ; ecx is the amount of pixels to blur
  23
  24 blur16_loop:
  25 mov ax,word[edi]
  26
  27 mov dx,ax
  28 and ax,0x07e0
  29 and dx,0xf81f
  30 rol eax,16
  31 mov ax,dx
  32 ; Now we have unwrapped the green middle out of eax
  33 mov edx,eax ; ebx=this pixel (unwrapped) before we changed it
  34 add eax,ebx ; add last pixel to this one
  35 mov ebx,edx ; ebx=this pixel for next time
  36
  37 sar eax,1
  38
  39 ; wrap up again
  40 mov edx,eax
  41 ror edx,16
  42 and dx,0x07e0
  43 and ax,0xf81f
  44 or  ax,dx
  45 ;finished pixel in ax
  46
  47 ;mov word[edi],ax
  48 ;add edi,2
  49 stosw
  50 loop blur16_loop
  51
  52 pop  ebx
  53 pop  ecx
  54 pop  edx
  55 pop  edi
  56 xor eax,eax
  57 ret
  58
  59
  60 ; --------------------------------------
  61
  62 bits 32
  63 section .text
  64 ;extern "C" int blur_bitmap_15
  65 ;  (unsigned char *dest,int len);
  66
  67 global blur_bitmap_15
  68 times ($$-$) & 3 db 0
  69 blur_bitmap_15:
  70 push edi ; point to screen
  71 push edx ; temporary for unwrapping
  72 push ecx ; count
  73 push ebx ; last pixel
  74
  75 ; ax = current pixel
  76
  77 xor ebx,ebx ; Last pixel
  78
  79 mov edi,[esp+20] ; edi is a pointer to the bitmap
  80 mov ecx,[esp+24] ; ecx is the amount of pixels to blur
  81
  82 blur15_loop:
  83 mov ax,word[edi]
  84
  85 mov dx,ax
  86 and ax,0x03e0
  87 and dx,0x7c1f
  88 rol eax,16
  89 mov ax,dx
  90 ; Now we have unwrapped the green middle out of eax
  91 mov edx,eax ; ebx=this pixel (unwrapped) before we changed it
  92 add eax,ebx ; add last pixel to this one
  93 mov ebx,edx ; ebx=this pixel for next time
  94
  95 sar eax,1
  96
  97 ; wrap up again
  98 mov edx,eax
  99 ror edx,16
 100 and dx,0x03e0
 101 and ax,0x7c1f
 102 or  ax,dx
 103 ;finished pixel in ax
 104
 105 ;mov word[edi],ax
 106 ;add edi,2
 107 stosw
 108 loop blur15_loop
 109
 110 pop  ebx
 111 pop  ecx
 112 pop  edx
 113 pop  edi
 114 xor eax,eax
 115 ret
 116
 117 ; ----------------------------
 118
 119 bits 32
 120 section .text
 121 ;extern "C" int test_ctv
 122 ;  (unsigned char *dest,int len);
 123
 124 global _test_ctv
 125 times ($$-$) & 3 db 0
 126 test_ctv:
 127 push edi ; point to screen
 128 push edx ; temporary for unwrapping
 129 push ecx ; count
 130 push ebx ; last pixel
 131
 132 ; ax = current pixel
 133
 134 xor ebx,ebx ; Last pixel
 135
 136 mov edi,[esp+20] ; edi is a pointer to the bitmap
 137 mov ecx,[esp+24] ; ecx is the amount of pixels to blur
 138
 139 test_loop:
 140 mov ax,word[edi]
 141
 142 mov dx,ax
 143 rol eax,16
 144 mov ax,dx
 145 mov edx,eax ; ebx=this pixel (unwrapped) before we changed it
 146 mov ebx,edx ; ebx=this pixel for next time
 147
 148 sar eax,1
 149
 150 mov edx,eax
 151 ror edx,16
 152 ;finished pixel in ax
 153
 154 ;mov word[edi],ax
 155 ;add edi,2
 156 stosw
 157 loop test_loop
 158
 159 pop  ebx
 160 pop  ecx
 161 pop  edx
 162 pop  edi
 163 xor eax,eax
 164 ret
 165
 166 %ifdef NASM_STACK_NOEXEC
 167 section .note.GNU-stack noalloc noexec nowrite progbits
 168 %endif