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almost finished doing error handling better

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luna 2025-07-26 20:27:25 +02:00
parent 71fe30e14a
commit 92a5143df8
5 changed files with 59 additions and 24 deletions
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6
src/convert.cpp
View file

@ -6,8 +6,10 @@ std::expected<bool, lily_png::CONVERT_ERROR> lily_png::convert_to_R32G32B32A32(f
return std::unexpected(CONVERT_ERROR::color_type_mismatch); return std::unexpected(CONVERT_ERROR::color_type_mismatch);
if (!(meta.bit_depth == 8 || meta.bit_depth == 16)) if (!(meta.bit_depth == 8 || meta.bit_depth == 16))
return std::unexpected(CONVERT_ERROR::non_standard_bit_depth); return std::unexpected(CONVERT_ERROR::non_standard_bit_depth);
auto uncompress_ret = get_uncompressed_size(meta);
size_t size = get_uncompressed_size(meta); if (!uncompress_ret)
return std::unexpected(CONVERT_ERROR::non_standard_bit_depth);
size_t size = uncompress_ret.value();
size_t dest_size = 0; size_t dest_size = 0;
if (meta.bit_depth == 8) if (meta.bit_depth == 8)
{ {

15
src/filter.cpp
View file

@ -2,7 +2,10 @@
std::expected<bool, lily_png::png_error> lily_png::filter_scanline(unsigned char *scanline, unsigned char *previous_scanline, unsigned char *dest, metadata &meta, unsigned char filter_type) std::expected<bool, lily_png::png_error> lily_png::filter_scanline(unsigned char *scanline, unsigned char *previous_scanline, unsigned char *dest, metadata &meta, unsigned char filter_type)
{ {
size_t pixel_size = get_pixel_bit_size(meta); auto pixel_size_ret = get_pixel_bit_size(meta);
if (!pixel_size_ret)
return std::unexpected(pixel_size_ret.error());
size_t pixel_size = pixel_size_ret.value();
size_t pixel_size_bytes = (pixel_size + 7)/8; size_t pixel_size_bytes = (pixel_size + 7)/8;
size_t scanline_size = (meta.width * pixel_size + 7)/8; size_t scanline_size = (meta.width * pixel_size + 7)/8;
for (int i = 0; i < scanline_size; i++) for (int i = 0; i < scanline_size; i++)
@ -47,11 +50,17 @@ std::expected<bool, lily_png::png_error> lily_png::filter(file_reader::buffer<un
{ {
unsigned long index = 0; unsigned long index = 0;
unsigned long index_dest = 0; unsigned long index_dest = 0;
size_t pixel_size = get_pixel_bit_size(meta); auto pixel_size_ret = get_pixel_bit_size(meta);
if (!pixel_size_ret)
return std::unexpected(pixel_size_ret.error());
size_t pixel_size = pixel_size_ret.value();
size_t pixel_size_bytes = (pixel_size + 7)/8; size_t pixel_size_bytes = (pixel_size + 7)/8;
size_t scanline_size = (meta.width * pixel_size + 7)/8; size_t scanline_size = (meta.width * pixel_size + 7)/8;
unsigned long scanlines = 0; unsigned long scanlines = 0;
dest.allocate(get_uncompressed_size(meta)); auto uncompress_ret = get_uncompressed_size(meta);
if (!uncompress_ret)
return std::unexpected(uncompress_ret.error());
dest.allocate(uncompress_ret.value());
unsigned char *previous_scanline = nullptr; unsigned char *previous_scanline = nullptr;
while (scanlines < meta.height) while (scanlines < meta.height)
{ {

34
src/lily_png.cpp
View file

@ -91,7 +91,10 @@ static std::expected<bool, lily_png::png_error> read_raw_data(const std::string
break; break;
} }
data.allocate(get_uncompressed_size(meta)); auto uncompress_ret = get_uncompressed_size(meta);
if (!uncompress_ret)
return std::unexpected(uncompress_ret.error());
data.allocate(uncompress_ret.value());
size_t prev_allocated = data.allocated; size_t prev_allocated = data.allocated;
int r = uncompress(data.data, &prev_allocated, raw_dat.data, raw_dat.allocated); int r = uncompress(data.data, &prev_allocated, raw_dat.data, raw_dat.allocated);
if (r != Z_OK) if (r != Z_OK)
@ -103,9 +106,12 @@ static std::expected<bool, lily_png::png_error> read_raw_data(const std::string
} }
static void apply_palette_scanline(unsigned char *scanline, unsigned char *dest, lily_png::metadata &meta) static std::expected<bool, lily_png::png_error> apply_palette_scanline(unsigned char *scanline, unsigned char *dest, lily_png::metadata &meta)
{ {
size_t pixel_size = get_pixel_bit_size(meta); auto pixel_size_ret = get_pixel_bit_size(meta);
if (!pixel_size_ret)
return std::unexpected(pixel_size_ret.error());
size_t pixel_size = pixel_size_ret.value();
size_t pixel_size_bytes = (pixel_size + 7)/8; size_t pixel_size_bytes = (pixel_size + 7)/8;
size_t scanline_size = (meta.width * pixel_size + 7)/8; size_t scanline_size = (meta.width * pixel_size + 7)/8;
unsigned long dest_index = 0; unsigned long dest_index = 0;
@ -116,26 +122,36 @@ static void apply_palette_scanline(unsigned char *scanline, unsigned char *dest,
dest[dest_index++] = tmp_color.g; dest[dest_index++] = tmp_color.g;
dest[dest_index++] = tmp_color.b; dest[dest_index++] = tmp_color.b;
} }
return true;
} }
static void apply_palette(file_reader::buffer<unsigned char> &data, file_reader::buffer<unsigned char> &dest, lily_png::metadata &meta) static std::expected<bool, lily_png::png_error> apply_palette(file_reader::buffer<unsigned char> &data, file_reader::buffer<unsigned char> &dest, lily_png::metadata &meta)
{ {
unsigned long index = 0; unsigned long index = 0;
unsigned long index_dest = 0; unsigned long index_dest = 0;
size_t pixel_size = lily_png::get_pixel_bit_size(meta); auto pixel_size_ret = get_pixel_bit_size(meta);
if (!pixel_size_ret)
return std::unexpected(pixel_size_ret.error());
size_t pixel_size = pixel_size_ret.value();
size_t pixel_size_bytes = (pixel_size + 7)/8; size_t pixel_size_bytes = (pixel_size + 7)/8;
size_t scanline_size = (meta.width * pixel_size + 7)/8; size_t scanline_size = (meta.width * pixel_size + 7)/8;
unsigned long scanlines = 0; unsigned long scanlines = 0;
dest.allocate(get_uncompressed_size(meta) * 3); auto uncompress_ret = get_uncompressed_size(meta);
if (!uncompress_ret)
return std::unexpected(uncompress_ret.error());
dest.allocate(uncompress_ret.value() * 3);
while (scanlines < meta.height) while (scanlines < meta.height)
{ {
unsigned char filter = data.data[index]; unsigned char filter = data.data[index];
std::println("Filter {}", filter); std::println("Filter {}", filter);
apply_palette_scanline(&data.data[index + 1], &dest.data[index_dest], meta); auto ret = apply_palette_scanline(&data.data[index + 1], &dest.data[index_dest], meta);
if (!ret)
return std::unexpected(ret.error());
index += scanline_size + 1; index += scanline_size + 1;
index_dest += scanline_size; index_dest += scanline_size;
scanlines++; scanlines++;
} }
return true;
} }
std::expected<lily_png::metadata, lily_png::png_error> lily_png::read_png(const std::string &file_path, file_reader::buffer<unsigned char> &data) std::expected<lily_png::metadata, lily_png::png_error> lily_png::read_png(const std::string &file_path, file_reader::buffer<unsigned char> &data)
@ -150,7 +166,9 @@ std::expected<lily_png::metadata, lily_png::png_error> lily_png::read_png(const
if (palette_found == true) if (palette_found == true)
{ {
file_reader::buffer<unsigned char> dest_palette{}; file_reader::buffer<unsigned char> dest_palette{};
apply_palette(tmp_data, dest_palette, meta); auto apply_ret = apply_palette(tmp_data, dest_palette, meta);
if (!apply_ret)
return std::unexpected(apply_ret.error());
tmp_data = dest_palette; tmp_data = dest_palette;
} }
auto res = filter(tmp_data, data, meta); auto res = filter(tmp_data, data, meta);

19
src/utils.cpp
View file

@ -1,7 +1,7 @@
#include "utils.h" #include "utils.h"
size_t lily_png::get_pixel_bit_size(const metadata &meta) std::expected<size_t, lily_png::png_error> lily_png::get_pixel_bit_size(const metadata &meta)
{ {
size_t ret = 0; size_t ret = 0;
switch (meta.color_type) switch (meta.color_type)
@ -20,7 +20,7 @@ size_t lily_png::get_pixel_bit_size(const metadata &meta)
ret = meta.bit_depth * 3; ret = meta.bit_depth * 3;
} }
else else
throw std::runtime_error("Invalid bit depht"); return std::unexpected(png_error::invalid_bit_depth);
break; break;
case static_cast<int>(color::indexed): case static_cast<int>(color::indexed):
if (meta.bit_depth == 1 || meta.bit_depth == 2 || meta.bit_depth == 4 || meta.bit_depth == 8) if (meta.bit_depth == 1 || meta.bit_depth == 2 || meta.bit_depth == 4 || meta.bit_depth == 8)
@ -28,7 +28,7 @@ size_t lily_png::get_pixel_bit_size(const metadata &meta)
ret = meta.bit_depth; ret = meta.bit_depth;
} }
else else
throw std::runtime_error("Invalid bit depht"); return std::unexpected(png_error::invalid_bit_depth);
break; break;
case static_cast<int>(color::grayscale_alpha): case static_cast<int>(color::grayscale_alpha):
if (meta.bit_depth == 8 || meta.bit_depth == 16) if (meta.bit_depth == 8 || meta.bit_depth == 16)
@ -36,7 +36,7 @@ size_t lily_png::get_pixel_bit_size(const metadata &meta)
ret = meta.bit_depth * 2; ret = meta.bit_depth * 2;
} }
else else
throw std::runtime_error("Invalid bit depht"); return std::unexpected(png_error::invalid_bit_depth);
break; break;
case static_cast<int>(color::rgba): case static_cast<int>(color::rgba):
if (meta.bit_depth == 8 || meta.bit_depth == 16) if (meta.bit_depth == 8 || meta.bit_depth == 16)
@ -44,17 +44,20 @@ size_t lily_png::get_pixel_bit_size(const metadata &meta)
ret = meta.bit_depth * 4; ret = meta.bit_depth * 4;
} }
else else
throw std::runtime_error("Invalid bit depht"); return std::unexpected(png_error::invalid_bit_depth);
break; break;
default: default:
throw std::runtime_error("Invalid color type"); return std::unexpected(png_error::invalid_color_type);
} }
return ret; return ret;
} }
size_t lily_png::get_uncompressed_size(const metadata &meta) std::expected<size_t, lily_png::png_error> lily_png::get_uncompressed_size(const metadata &meta)
{ {
size_t ret = (meta.width * get_pixel_bit_size(meta) + 7)/8; //ceil() but for bytes auto pixel_ret = get_pixel_bit_size(meta);
if (!pixel_ret)
return std::unexpected(pixel_ret.error());
size_t ret = (meta.width * pixel_ret.value() + 7)/8; //ceil() but for bytes
ret = (ret + 1) * meta.height; ret = (ret + 1) * meta.height;
std::println("Uncompressed size {}", ret); std::println("Uncompressed size {}", ret);
return ret; return ret;

9
src/utils.h
View file

@ -1,5 +1,6 @@
#pragma once #pragma once
#include "metadata.h" #include "metadata.h"
#include <expected>
namespace lily_png namespace lily_png
{ {
@ -8,9 +9,11 @@ namespace lily_png
file_doesnt_exist, file_doesnt_exist,
read_failed, read_failed,
file_is_not_a_png, file_is_not_a_png,
non_standard_filter non_standard_filter,
invalid_bit_depth,
invalid_color_type
}; };
size_t get_pixel_bit_size(const metadata &meta); std::expected<size_t, png_error> get_pixel_bit_size(const metadata &meta);
size_t get_uncompressed_size(const metadata &meta); std::expected<size_t, png_error> get_uncompressed_size(const metadata &meta);
int paeth_predict(const int a, const int b, const int c); int paeth_predict(const int a, const int b, const int c);
} }