rle.c 1.7 KB

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  1. #include "rle.h"
  2. #include "fileops.h"
  3. uint8_t rle_file_getc()
  4. {
  5. static uint16_t rle_filled = 0;
  6. static uint8_t data;
  7. if ( !rle_filled )
  8. {
  9. data = file_getc();
  10. switch ( data )
  11. {
  12. case RLE_RUN:
  13. data = file_getc();
  14. rle_filled = file_getc() - 1;
  15. break;
  16. case RLE_RUNLONG:
  17. data = file_getc();
  18. rle_filled = file_getc();
  19. rle_filled |= file_getc() << 8;
  20. rle_filled--;
  21. break;
  22. case RLE_ESC:
  23. data = file_getc();
  24. break;
  25. }
  26. }
  27. else
  28. {
  29. rle_filled--;
  30. }
  31. if ( file_status || file_res )
  32. {
  33. rle_filled = 0;
  34. }
  35. return data;
  36. }
  37. void rle_mem_init( const uint8_t *address, uint32_t len )
  38. {
  39. rle_mem_ptr = address;
  40. rle_mem_endptr = address + len;
  41. rle_state = 0;
  42. }
  43. uint8_t rle_mem_getc()
  44. {
  45. static uint16_t rle_mem_filled = 0;
  46. static uint8_t rle_mem_data;
  47. if ( !rle_mem_filled )
  48. {
  49. rle_mem_data = *( rle_mem_ptr++ );
  50. switch ( rle_mem_data )
  51. {
  52. case RLE_RUN:
  53. rle_mem_data = *( rle_mem_ptr )++;
  54. rle_mem_filled = *( rle_mem_ptr )++ - 1;
  55. break;
  56. case RLE_RUNLONG:
  57. rle_mem_data = *( rle_mem_ptr )++;
  58. rle_mem_filled = *( rle_mem_ptr )++;
  59. rle_mem_filled |= *( rle_mem_ptr )++ << 8;
  60. rle_mem_filled--;
  61. break;
  62. case RLE_ESC:
  63. rle_mem_data = *( rle_mem_ptr )++;
  64. break;
  65. }
  66. }
  67. else
  68. {
  69. rle_mem_filled--;
  70. }
  71. if ( rle_mem_ptr >= rle_mem_endptr )
  72. {
  73. rle_mem_filled = 0;
  74. rle_state = 1;
  75. }
  76. return rle_mem_data;
  77. }