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-rw-r--r--SharedGraphics/PNGLoader.cpp131
-rw-r--r--SharedGraphics/Size.h2
2 files changed, 81 insertions, 52 deletions
diff --git a/SharedGraphics/PNGLoader.cpp b/SharedGraphics/PNGLoader.cpp
index 7c328af946..264844d264 100644
--- a/SharedGraphics/PNGLoader.cpp
+++ b/SharedGraphics/PNGLoader.cpp
@@ -33,8 +33,14 @@ struct PNGLoadingContext {
byte compression_method { 0 };
byte filter_method { 0 };
byte interlace_method { 0 };
+ byte bytes_per_pixel { 0 };
+ bool has_seen_zlib_header { false };
+ bool has_alpha() const { return color_type & 4; }
Vector<Scanline> scanlines;
RetainPtr<GraphicsBitmap> bitmap;
+ byte* decompression_buffer { nullptr };
+ int decompression_buffer_size { 0 };
+ Vector<byte> compressed_data;
};
class Streamer {
@@ -158,6 +164,30 @@ static RetainPtr<GraphicsBitmap> load_png_impl(const byte* data, int data_size)
}
}
+ unsigned long srclen = context.compressed_data.size() - 6;
+ unsigned long destlen = context.decompression_buffer_size;
+ int ret = puff(context.decompression_buffer, &destlen, context.compressed_data.data() + 2, &srclen);
+ if (ret < 0)
+ return nullptr;
+ context.compressed_data.clear();
+
+ {
+ Streamer streamer(context.decompression_buffer, context.decompression_buffer_size);
+ for (int y = 0; y < context.height; ++y) {
+ byte filter;
+ if (!streamer.read(filter))
+ return nullptr;
+
+ context.scanlines.append({ filter, ByteBuffer::create_uninitialized(context.width * context.bytes_per_pixel) });
+ auto& scanline_buffer = context.scanlines.last().data;
+ if (!streamer.read_bytes(scanline_buffer.pointer(), scanline_buffer.size()))
+ return nullptr;
+ }
+ munmap(context.decompression_buffer, context.decompression_buffer_size);
+ context.decompression_buffer = nullptr;
+ context.decompression_buffer_size = 0;
+ }
+
context.bitmap = GraphicsBitmap::create(GraphicsBitmap::Format::RGBA32, { context.width, context.height });
union [[gnu::packed]] Pixel {
@@ -171,11 +201,28 @@ static RetainPtr<GraphicsBitmap> load_png_impl(const byte* data, int data_size)
};
static_assert(sizeof(Pixel) == 4);
- printf("unfiltering %d scanlines\n", context.height);
for (int y = 0; y < context.height; ++y) {
auto filter = context.scanlines[y].filter;
- printf("[%d] filter=%u\n", y, context.scanlines[y].filter);
- memcpy(context.bitmap->scanline(y), context.scanlines[y].data.pointer(), context.scanlines[y].data.size());
+ switch (context.color_type) {
+ case 2: {
+ struct [[gnu::packed]] Triplet { byte r; byte g; byte b; };
+ auto* triplets = (Triplet*)context.scanlines[y].data.pointer();
+ for (int i = 0; i < context.width; ++i) {
+ auto& pixel = (Pixel&)context.bitmap->scanline(y)[i];
+ pixel.r = triplets[i].r;
+ pixel.g = triplets[i].g;
+ pixel.b = triplets[i].b;
+ pixel.a = 0xff;
+ }
+ break;
+ }
+ case 6:
+ memcpy(context.bitmap->scanline(y), context.scanlines[y].data.pointer(), context.scanlines[y].data.size());
+ break;
+ default:
+ ASSERT_NOT_REACHED();
+ break;
+ }
if (filter == 0)
continue;
for (int i = 0; i < context.width; ++i) {
@@ -192,28 +239,26 @@ static RetainPtr<GraphicsBitmap> load_png_impl(const byte* data, int data_size)
x.r += a.r;
x.g += a.g;
x.b += a.b;
- x.a += a.a;
- }
-
- if (filter == 2) {
+ if (context.has_alpha())
+ x.a += a.a;
+ } else if (filter == 2) {
x.r += b.r;
x.g += b.g;
x.b += b.b;
- x.a += b.a;
- }
-
- if (filter == 3) {
+ if (context.has_alpha())
+ x.a += b.a;
+ } if (filter == 3) {
x.r = x.r + ((a.r + b.r) / 2);
x.g = x.g + ((a.g + b.g) / 2);
x.b = x.b + ((a.b + b.b) / 2);
- x.a = x.a + ((a.a + b.a) / 2);
- }
-
- if (filter == 4) {
+ if (context.has_alpha())
+ x.a = x.a + ((a.a + b.a) / 2);
+ } if (filter == 4) {
x.r += paeth_predictor(a.r, b.r, c.r);
x.g += paeth_predictor(a.g, b.g, c.g);
x.b += paeth_predictor(a.b, b.b, c.b);
- x.a += paeth_predictor(a.a, b.a, c.a);
+ if (context.has_alpha())
+ x.a += paeth_predictor(a.a, b.a, c.a);
}
}
}
@@ -233,46 +278,30 @@ static bool process_IHDR(const ByteBuffer& data, PNGLoadingContext& context)
context.compression_method = ihdr.compression_method;
context.filter_method = ihdr.filter_method;
context.interlace_method = ihdr.interlace_method;
+
+ switch (context.color_type) {
+ case 2:
+ context.bytes_per_pixel = 3;
+ break;
+ case 6:
+ context.bytes_per_pixel = 4;
+ break;
+ default:
+ ASSERT_NOT_REACHED();
+ }
+
+ printf("PNG: %dx%d (%d bpp)\n", context.width, context.height, context.bit_depth);
+ printf(" Color type: %b\n", context.color_type);
+ printf(" Interlace type: %b\n", context.interlace_method);
+
+ context.decompression_buffer_size = (context.width * context.height * context.bytes_per_pixel + context.height);
+ context.decompression_buffer = (byte*)mmap(nullptr, context.decompression_buffer_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
return true;
}
static bool process_IDAT(const ByteBuffer& data, PNGLoadingContext& context)
{
- for (int i = 0; i < data.size(); ++i) {
- printf("%c", data[i]);
- }
- printf("\n");
-
- printf("first byte into puff: %c (%b)\n", data[0], data[0]);
-
- struct [[gnu::packed]] ZlibHeader {
- byte compression_method : 4;
- byte compression_info : 4;
- byte flags;
- };
- static_assert(sizeof(ZlibHeader) == 2);
-
- auto& zhdr = *(ZlibHeader*)data.pointer();
- printf("compression_method: %u\n", zhdr.compression_method);
- printf("compression_info: %u\n", zhdr.compression_info);
- printf("flags: %b\n", zhdr.flags);
-
- unsigned long destlen = (context.width * context.height * sizeof(RGBA32)) + context.height;
- unsigned long srclen = data.size() - 2;
- auto decompression_buffer = ByteBuffer::create_uninitialized(destlen + context.height);
- int ret = puff(decompression_buffer.pointer(), &destlen, data.pointer() + 2, &srclen);
- if (ret != 0)
- return false;
- Streamer streamer(decompression_buffer.pointer(), decompression_buffer.size());
- for (int y = 0; y < context.height; ++y) {
- byte filter;
- if (!streamer.read(filter))
- return false;
- context.scanlines.append({ filter, ByteBuffer::create_uninitialized(context.width * sizeof(RGBA32)) });
- auto& scanline_buffer = context.scanlines.last().data;
- if (!streamer.read_bytes(scanline_buffer.pointer(), scanline_buffer.size()))
- return false;
- }
+ context.compressed_data.append(data.pointer(), data.size());
return true;
}
diff --git a/SharedGraphics/Size.h b/SharedGraphics/Size.h
index 469bb7aaf9..77638cca2f 100644
--- a/SharedGraphics/Size.h
+++ b/SharedGraphics/Size.h
@@ -48,7 +48,7 @@ public:
operator WSAPI_Size() const;
- String to_string() const { return String::format("[%d,%d]", m_width, m_height); }
+ String to_string() const { return String::format("[%dx%d]", m_width, m_height); }
private:
int m_width { 0 };
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-16 13:55:55 +0000