arm/video_blend.S

   1 .align 2\r
   2 \r
   3 .global expand_blend\r
   4 .global expand_normal\r
   5 \r
   6 @ Input:\r
   7 @   r0 = screen_src_ptr\r
   8 @   r1 = screen_dest_ptr\r
   9 @   r2 = start\r
  10 @   r3 = end\r
  11 \r
  12 6:\r
  13   .word io_registers\r
  14   .word palette_ram_converted\r
  15   .word 0x04000200                @ combine test mask\r
  16   .word 0x07E0F81F                @ clamp mask\r
  17   .word 0x000003FE                @ palette index mask\r
  18   .word 0x08010020                @ saturation mask\r
  19 \r
  20 expand_blend:\r
  21   stmdb sp!, { r4, r5, r6, r9, r10, r11, r14 }\r
  22 \r
  23   add r0, r0, r2, lsl #2          @ screen_src_ptr += start\r
  24   add r1, r1, r2, lsl #1          @ screen_dest_ptr += start\r
  25   sub r2, r3, r2                  @ r2 = end - start\r
  26   ldr r3, 6b                      @ r3 = io_registers\r
  27   ldrh r3, [r3, #0x52]            @ r3 = bldalpha\r
  28   mov r4, r3, lsr #8              @ r4 = bldalpha >> 8\r
  29   and r3, r3, #0x1F               @ r3 = blend_a\r
  30   and r4, r4, #0x1F               @ r4 = blend_b\r
  31   cmp r3, #16                     @ if(blend_a > 16)\r
  32   movgt r3, #16                   @   blend_a = 16\r
  33   cmp r4, #16                     @ if(blend_b > 16)\r
  34   movgt r3, #16                   @   blend_b = 16\r
  35 \r
  36   ldr r14, 6b + 4                 @ r14 = palette_ram_converted\r
  37   ldr r12, 6b + 8                 @ r12 = 0x04000200\r
  38   ldr r11, 6b + 12                @ r11 = 0x07E0F81F\r
  39   ldr r10, 6b + 16                @ r10 = 0x000003FE\r
  40 \r
  41   add r5, r3, r4                  @ r5 = blend_a + blend_b\r
  42   cmp r5, #16                     @ if((blend_a + blend_b) > 16)\r
  43   bgt 3f                          @   goto loop w/saturation\r
  44 \r
  45 \r
  46   @ loop w/o saturation\r
  47 1:\r
  48   ldr r5, [r0], #4                @ r5 = pixel_pair, screen_src_ptr++\r
  49   and r6, r5, r12                 @ r6 = r5 & 0x04000200\r
  50   cmp r6, r12                     @ if(r6 != 0x4000200)\r
  51   bne 2f                          @   goto no_blend\r
  52 \r
  53   and r6, r10, r5, lsl #1         @ r6 = (pixel_pair & 0x1FF) << 1\r
  54   ldrh r6, [r14, r6]              @ r6 = pixel_top\r
  55   orr r6, r6, r6, lsl #16         @ r6 = pixel_top | (pixel_top << 16)\r
  56   and r6, r6, r11                 @ r6 = pixel_top_dilated\r
  57 \r
  58   and r5, r10, r5, lsr #15        @ r5 = ((pixel_pair >> 16) & 0x1FF) << 1\r
  59   ldrh r5, [r14, r5]              @ r5 = pixel_bottom\r
  60   orr r5, r5, r5, lsl #16         @ r5 = pixel_bottom | (pixel_bottom << 16)\r
  61   and r5, r5, r11                 @ r5 = pixel_bottom_dilated\r
  62 \r
  63   mul r5, r4, r5                  @ r5 = pixel_bottom * blend_b = bottom_mul\r
  64   mla r5, r3, r6, r5              @ r5 = (pixel_top * blend_a) + bottom_mul\r
  65 \r
  66   and r5, r11, r5, lsr #4         @ r5 = (color_dilated >> 4) & 0x07E0F81F\r
  67   orr r5, r5, r5, lsr #16         @ r5 = color_dilated | (color_dilated >> 16)\r
  68 \r
  69   strh r5, [r1], #2               @ *screen_dest_ptr = r5, screen_dest_ptr++\r
  70   subs r2, r2, #1                 @ counter--\r
  71   bne 1b                          @ go again\r
  72 \r
  73   ldmia sp!, { r4, r5, r6, r9, r10, r11, pc }\r
  74 \r
  75 2:\r
  76   and r5, r10, r5, lsl #1         @ r5 = (pixel_pair & 0x1FF) << 1\r
  77   ldrh r5, [r14, r5]              @ r5 = pixel_top\r
  78   strh r5, [r1], #2               @ *screen_dest_ptr = r5, screen_dest_ptr++\r
  79 \r
  80   subs r2, r2, #1                 @ counter--\r
  81   bne 1b                          @ go again\r
  82 \r
  83   ldmia sp!, { r4, r5, r6, r9, r10, r11, pc }\r
  84 \r
  85 @ loop w/saturation\r
  86 \r
  87 3:\r
  88   ldr r9, 6b + 20                 @ r9 = 0x08010020\r
  89 \r
  90 4:\r
  91   ldr r5, [r0], #4                @ r5 = pixel_pair, screen_src_ptr++\r
  92   and r6, r5, r12                 @ r6 = r5 & 0x04000200\r
  93   cmp r6, r12                     @ if(r6 != 0x4000200)\r
  94   bne 5f                          @   goto no_blend\r
  95 \r
  96   and r6, r10, r5, lsl #1         @ r6 = (pixel_pair & 0x1FF) << 1\r
  97   ldrh r6, [r14, r6]              @ r6 = pixel_top\r
  98   orr r6, r6, r6, lsl #16         @ r6 = pixel_top | (pixel_top << 16)\r
  99   and r6, r6, r11                 @ r6 = pixel_top_dilated\r
 100 \r
 101   and r5, r10, r5, lsr #15        @ r5 = ((pixel_pair >> 16) & 0x1FF) << 1\r
 102   ldrh r5, [r14, r5]              @ r5 = pixel_bottom\r
 103   orr r5, r5, r5, lsl #16         @ r5 = pixel_bottom | (pixel_bottom << 16)\r
 104   and r5, r5, r11                 @ r5 = pixel_bottom_dilated\r
 105 \r
 106   mul r5, r4, r5                  @ r5 = pixel_bottom * blend_b = bottom_mul\r
 107   mla r5, r3, r6, r5              @ r5 = (pixel_top * blend_a) + bottom_mul\r
 108 \r
 109   and r6, r9, r5, lsr #4          @ r6 = saturation bits\r
 110   orr r6, r6, r6, lsr #1          @ propogate saturation down msb\r
 111   orr r6, r6, r6, lsr #2          @ propogate down next two bits\r
 112   orr r6, r6, r6, lsr #3          @ propogate down next three bits\r
 113   orr r5, r6, r5, lsr #4          @ mask over result w/saturation\r
 114 \r
 115   and r5, r11, r5                 @ r5 = (color_dilated >> 4) & 0x07E0F81F\r
 116   orr r5, r5, r5, lsr #16         @ r5 = color_dilated | (color_dilated >> 16)\r
 117   strh r5, [r1], #2               @ *screen_dest_ptr = r5, screen_dest_ptr++\r
 118 \r
 119   subs r2, r2, #1                 @ counter--\r
 120   bne 4b                          @ go again\r
 121 \r
 122   ldmia sp!, { r4, r5, r6, r9, r10, r11, pc }\r
 123 \r
 124 5:\r
 125   and r5, r10, r5, lsl #1         @ r5 = (pixel_pair & 0x1FF) << 1\r
 126   ldrh r5, [r14, r5]              @ r5 = pixel_top\r
 127   strh r5, [r1], #2               @ *screen_dest_ptr = r5, screen_dest_ptr++\r
 128 \r
 129   subs r2, r2, #1                 @ counter--\r
 130   bne 4b                          @ go again\r
 131 \r
 132   ldmia sp!, { r4, r5, r6, r9, r10, r11, pc }\r
 133 \r
 134 \r
 135 \r
 136 @ The following function isn't complete (only works on run multiples of 8),\r
 137 @ but unfortunately I don't see much potential for actually being able to\r
 138 @ use it..\r
 139 \r
 140 #define expand_pixel_pair(reg, temp)                                         ;\\r
 141   and temp, r3, reg, lsr #15                                                 ;\\r
 142   ldrh temp, [r2, temp]                                                      ;\\r
 143                                                                              ;\\r
 144   and reg, r3, reg, lsl #1                                                   ;\\r
 145   ldrh reg, [r2, reg]                                                        ;\\r
 146                                                                              ;\\r
 147   orr reg, reg, temp, lsl #16                                                ;\\r
 148 \r
 149 \r
 150 @ Input:\r
 151 @   r0 = screen_ptr\r
 152 @   r1 = start\r
 153 @   r2 = end\r
 154 \r
 155 1:\r
 156   .word palette_ram_converted\r
 157   .word 0x3FE\r
 158 \r
 159 expand_normal:\r
 160   stmdb sp!, { r4, r5, r6, r7, r14 }\r
 161 \r
 162   add r0, r0, r1, lsl #1          @ screen_ptr += start\r
 163   sub r1, r2, r1                  @ r1 = end - start\r
 164   ldr r2, 1b                      @ r2 = palette_ram_converted\r
 165   ldr r3, 1b + 4                  @ r3 = 0x3FE\r
 166 \r
 167 2:\r
 168   ldmia r0, { r4, r5, r6, r7 }\r
 169 \r
 170   expand_pixel_pair(r4, r14)\r
 171   expand_pixel_pair(r5, r14)\r
 172   expand_pixel_pair(r6, r14)\r
 173   expand_pixel_pair(r7, r14)\r
 174 \r
 175   stmia r0!, { r4, r5, r6, r7 }\r
 176 \r
 177   subs r1, r1, #8\r
 178   bne 2b\r
 179 \r
 180   ldmia sp!, { r4, r5, r6, r7, pc }\r
 181 \r