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improvement but uncompress is broken

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Luna 2025-07-07 05:43:10 +02:00
parent a1f2a6d1af
commit 4150eec1d6
1 changed files with 71 additions and 6 deletions
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77
lily_png.cpp
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@ -21,6 +21,63 @@ static metadata parse_metadata(buffer &data)
return m;
}
static size_t get_uncompressed_size(const metadata meta)
{
size_t ret = 0;
switch (meta.color_type)
{
case 0:
if (meta.bit_depth == 1 || meta.bit_depth == 2 || meta.bit_depth == 4 || meta.bit_depth == 8 || meta.bit_depth == 16)
{
size_t size_per_row = ceil((meta.width * (meta.bit_depth))/8) + 1;
ret = size_per_row * meta.height;
}
else
throw std::runtime_error("Invalid bit depht");
break;
case 2:
if (meta.bit_depth == 8 || meta.bit_depth == 16)
{
size_t size_per_row = ceil((meta.width * (meta.bit_depth * 3))/8) + 1;
ret = size_per_row * meta.height;
}
else
throw std::runtime_error("Invalid bit depht");
break;
case 3:
if (meta.bit_depth == 1 || meta.bit_depth == 2 || meta.bit_depth == 4 || meta.bit_depth == 8)
{
size_t size_per_row = ceil((meta.width * (meta.bit_depth))/8) + 1;
ret = size_per_row * meta.height;
}
else
throw std::runtime_error("Invalid bit depht");
break;
case 4:
if (meta.bit_depth == 8 || meta.bit_depth == 16)
{
size_t size_per_row = ceil((meta.width * (meta.bit_depth * 2))/8) + 1;
ret = size_per_row * meta.height;
}
else
throw std::runtime_error("Invalid bit depht");
break;
case 6:
if (meta.bit_depth == 8 || meta.bit_depth == 16)
{
size_t size_per_row = ceil((meta.width * (meta.bit_depth * 4))/8) + 1;
ret = size_per_row * meta.height;
}
else
throw std::runtime_error("Invalid bit depht");
break;
default:
throw std::runtime_error("Invalid color type");
}
std::println("Uncompressed size {}", ret);
return ret;
}
buffer_unsigned read_png(const std::string &file_path)
{
unsigned char magic[9] = {137, 80, 78, 71, 13, 10, 26, 10};
@ -69,8 +126,16 @@ buffer_unsigned read_png(const std::string &file_path)
std::println("Image data size {}", image_data_concat.size);
std::println("Image data allocated {}", image_data_concat.allocated);
std::println("Allocations {}", image_data_concat.allocations);
image_data.allocate(image_data_concat.allocated);
uncompress(image_data.data, &image_data.allocated, image_data_concat.data, image_data_concat.size);
image_data.allocate(get_uncompressed_size(meta));
size_t prev_allocated = image_data.allocated;
int r = uncompress(image_data.data, &prev_allocated, image_data_concat.data, image_data_concat.size);
if (r != Z_OK)
{
std::println("Uncompress failed {}", r);
throw std::runtime_error("Uncompress fail");
}
image_data.size = prev_allocated;
std::println("Raw size {}", image_data.size);
std::println("Filter {}", (int)meta.filter);
switch (meta.filter)
@ -78,16 +143,16 @@ buffer_unsigned read_png(const std::string &file_path)
case 0:
break;
case 1:
std::println("sub filter now implemented");
std::println("sub filter not implemented");
break;
case 2:
std::println("up filter now implemented");
std::println("up filter not implemented");
break;
case 3:
std::println("average filter now implemented");
std::println("average filter not implemented");
break;
case 4:
std::println("paeth filter now implemented");
std::println("paeth filter not implemented");
break;
default:
std::println("Filter not recognised");