diff options
Diffstat (limited to 'lisiblepng/src/lisiblepng.c')
| -rw-r--r-- | lisiblepng/src/lisiblepng.c | 63 |
1 files changed, 27 insertions, 36 deletions
diff --git a/lisiblepng/src/lisiblepng.c b/lisiblepng/src/lisiblepng.c index 5fecb52..92edc3d 100644 --- a/lisiblepng/src/lisiblepng.c +++ b/lisiblepng/src/lisiblepng.c @@ -89,7 +89,7 @@ uint8_t ColourType_sample_count(const ColourType colour_type) { } struct Png { - char *data; + uint8_t *data; size_t width; size_t height; ColourType colour_type; @@ -358,8 +358,8 @@ static const ReconstructionFn reconstruction_functions[] = { paeth_reconstruction_function}; void apply_reconstruction_functions_to_scanline( - char *output_scanline, const char *input_scanline, - const char *previous_output_scanline, size_t filter_type, + uint8_t *output_scanline, const uint8_t *input_scanline, + const uint8_t *previous_output_scanline, size_t filter_type, size_t scanline_size, size_t bytes_per_pixel) { ASSERT(output_scanline != NULL); ASSERT(input_scanline != NULL); @@ -367,31 +367,31 @@ void apply_reconstruction_functions_to_scanline( sizeof(reconstruction_functions) / sizeof(ReconstructionFn)); for (size_t i = 0; i < scanline_size / bytes_per_pixel; i++) { - for (size_t p = 0; p < bytes_per_pixel; p++) { + for (size_t byte = 0; byte < bytes_per_pixel; byte++) { + size_t pixel_base = i * bytes_per_pixel; uint8_t a = 0; if (i > 0) { - a = output_scanline[i * bytes_per_pixel - bytes_per_pixel + p]; + a = output_scanline[pixel_base - bytes_per_pixel + byte]; } uint8_t b = 0; uint8_t c = 0; if (previous_output_scanline != NULL) { - b = previous_output_scanline[i * bytes_per_pixel + p]; + b = previous_output_scanline[pixel_base + byte]; if (i > 0) { - c = previous_output_scanline[i * bytes_per_pixel - bytes_per_pixel + - p]; + c = previous_output_scanline[pixel_base - bytes_per_pixel + byte]; } } - uint8_t x = input_scanline[i * bytes_per_pixel + p]; - output_scanline[i * bytes_per_pixel + p] = + uint8_t x = input_scanline[pixel_base + byte]; + output_scanline[pixel_base + byte] = reconstruction_functions[filter_type](a, b, c, x); } } } void apply_reconstruction_functions(Png *image, - const char *decompressed_data_buffer) { + const uint8_t *decompressed_data_buffer) { ASSERT(image != NULL); ASSERT(decompressed_data_buffer != NULL); size_t sample_count = ColourType_sample_count(image->colour_type); @@ -406,7 +406,7 @@ void apply_reconstruction_functions(Png *image, size_t output_scanline_start = scanline_size * scanline; size_t input_scanline_start = (scanline_size + 1) * scanline; uint8_t filter_type = decompressed_data_buffer[input_scanline_start]; - const char *previous_output_scanline = NULL; + const uint8_t *previous_output_scanline = NULL; if (scanline > 0) { size_t previous_output_scanline_start = scanline_size * (scanline - 1); previous_output_scanline = &image->data[previous_output_scanline_start]; @@ -494,7 +494,7 @@ Png *lis_Png_decode(FILE *stream) { png->colour_type = header.colour_type; png->bits_per_sample = header.bit_depth; size_t output_length; - char *output_buffer = + uint8_t *output_buffer = zlib_decompress(image_data.data, image_data.length, &output_length); png->data = output_buffer; @@ -528,42 +528,33 @@ void lis_Png_dump_ppm(const Png *png) { } for (size_t pixel_index = 0; pixel_index < png->height * png->width; pixel_index++) { - + size_t pixel_base = pixel_index * bytes_per_pixel; if (png->colour_type == ColourType_Greyscale) { if (bits_per_pixel == 16) { - uint8_t hi = png->data[pixel_index * bytes_per_pixel]; - uint8_t lo = png->data[pixel_index * bytes_per_pixel + 1]; - uint16_t grey = ((hi & 0xFFu) << 8) | (lo & 0xFFu); + uint16_t grey = + (png->data[pixel_base] << 8) | png->data[pixel_base + 1]; printf("%u %u %u\n", grey, grey, grey); } else { size_t absolute_bit_offset = pixel_index * bits_per_pixel; size_t byte_offset = absolute_bit_offset / 8; size_t relative_bit_offset = absolute_bit_offset % 8; - unsigned char grey = - (png->data[byte_offset] >> - (7 - relative_bit_offset - (bits_per_pixel - 1))) & - ((1 << bits_per_pixel) - 1); + uint8_t grey = (png->data[byte_offset] >> + (7 - relative_bit_offset - (bits_per_pixel - 1))) & + ((1 << bits_per_pixel) - 1); printf("%u %u %u\n", grey, grey, grey); } } else if (png->colour_type == ColourType_Truecolour) { if (png->bits_per_sample == 16) { - uint8_t hi_r = png->data[pixel_index * bytes_per_pixel]; - uint8_t lo_r = png->data[pixel_index * bytes_per_pixel + 1]; - uint16_t r = ((hi_r & 0xFFu) << 8) | (lo_r & 0xFFu); - - uint8_t hi_g = png->data[pixel_index * bytes_per_pixel + 2]; - uint8_t lo_g = png->data[pixel_index * bytes_per_pixel + 3]; - uint16_t g = ((hi_g & 0xFFu) << 8) | (lo_g & 0xFFu); - - uint8_t hi_b = png->data[pixel_index * bytes_per_pixel + 4]; - uint8_t lo_b = png->data[pixel_index * bytes_per_pixel + 5]; - uint16_t b = ((hi_b & 0xFFu) << 8) | (lo_b & 0xFFu); - + uint16_t r = (png->data[pixel_base] << 8) | png->data[pixel_base + 1]; + uint16_t g = + (png->data[pixel_base + 2] << 8) | png->data[pixel_base + 3]; + uint16_t b = + (png->data[pixel_base + 4] << 8) | png->data[pixel_base + 5]; printf("%u %u %u\n", r, g, b); } else { - uint8_t r = png->data[pixel_index * bytes_per_pixel]; - uint8_t g = png->data[pixel_index * bytes_per_pixel + 1]; - uint8_t b = png->data[pixel_index * bytes_per_pixel + 2]; + uint8_t r = png->data[pixel_base]; + uint8_t g = png->data[pixel_base + 1]; + uint8_t b = png->data[pixel_base + 2]; printf("%u %u %u\n", r, g, b); } } else { |