diff options
Diffstat (limited to 'Libraries/LibGfx')
| -rw-r--r-- | Libraries/LibGfx/GIFLoader.cpp | 76 |
1 files changed, 37 insertions, 39 deletions
diff --git a/Libraries/LibGfx/GIFLoader.cpp b/Libraries/LibGfx/GIFLoader.cpp index 773f3e7283..b849080206 100644 --- a/Libraries/LibGfx/GIFLoader.cpp +++ b/Libraries/LibGfx/GIFLoader.cpp @@ -56,7 +56,6 @@ struct ImageDescriptor { RGB color_map[256]; u8 lzw_min_code_size { 0 }; Vector<u8> lzw_encoded_bytes; - RefPtr<Gfx::Bitmap> bitmap; // Fields from optional graphic control extension block enum DisposalMethod : u8 { @@ -83,15 +82,17 @@ struct GIFLoadingContext { NotDecoded = 0, Error, FrameDescriptorsLoaded, + FrameComplete, }; State state { NotDecoded }; - size_t frames_decoded { 0 }; const u8* data { nullptr }; size_t data_size { 0 }; LogicalScreen logical_screen {}; u8 background_color_index { 0 }; NonnullOwnPtrVector<ImageDescriptor> images {}; size_t loops { 1 }; + RefPtr<Gfx::Bitmap> frame_buffer; + size_t current_frame { 0 }; }; RefPtr<Gfx::Bitmap> load_gif(const StringView& path) @@ -265,27 +266,28 @@ private: Vector<u8> m_output {}; }; -static void copy_frame(Bitmap& destination, Bitmap& source) -{ - for (int y = 0; y < source.height(); ++y) { - for (int x = 0; x < source.width(); ++x) { - destination.set_pixel(x, y, source.get_pixel(x, y)); - } - } -} - -static bool decode_frames_up_to_index(GIFLoadingContext& context, size_t frame_index) +static bool decode_frame(GIFLoadingContext& context, size_t frame_index) { if (frame_index >= context.images.size()) { return false; } - for (size_t i = context.frames_decoded; i <= frame_index; ++i) { + if (context.state >= GIFLoadingContext::State::FrameComplete && frame_index == context.current_frame) { + return true; + } + + size_t start_frame = context.current_frame + 1; + if (context.state < GIFLoadingContext::State::FrameComplete) { + start_frame = 0; + context.frame_buffer = Bitmap::create_purgeable(BitmapFormat::RGBA32, { context.logical_screen.width, context.logical_screen.height }); + } else if (frame_index < context.current_frame) { + start_frame = 0; + } + + for (size_t i = start_frame; i <= frame_index; ++i) { auto& image = context.images.at(i); printf("Image %zu: %d,%d %dx%d %zu bytes LZW-encoded\n", i, image.x, image.y, image.width, image.height, image.lzw_encoded_bytes.size()); - dbg() << "Decoding frame: " << i + 1 << " of " << context.images.size(); - LZWDecoder decoder(image.lzw_encoded_bytes, image.lzw_min_code_size); // Add GIF-specific control codes @@ -297,20 +299,17 @@ static bool decode_frames_up_to_index(GIFLoadingContext& context, size_t frame_i auto background_rgb = color_map[context.background_color_index]; Color background_color = Color(background_rgb.r, background_rgb.g, background_rgb.b); - image.bitmap = Bitmap::create_purgeable(BitmapFormat::RGBA32, { context.logical_screen.width, context.logical_screen.height }); - if (i == 0) { - image.bitmap->fill(background_color); + context.frame_buffer->fill(background_color); } const auto previous_image_disposal_method = i > 0 ? context.images.at(i - 1).disposal_method : ImageDescriptor::DisposalMethod::None; - if (i > 0 && (previous_image_disposal_method == ImageDescriptor::DisposalMethod::None || previous_image_disposal_method == ImageDescriptor::DisposalMethod::InPlace)) { - copy_frame(*image.bitmap, *context.images.at(i - 1).bitmap); - } else if (previous_image_disposal_method == ImageDescriptor::DisposalMethod::RestoreBackground) { - image.bitmap->fill(Color(Color::NamedColor::Transparent)); + if (previous_image_disposal_method == ImageDescriptor::DisposalMethod::RestoreBackground) { + context.frame_buffer->fill(Color(Color::NamedColor::Transparent)); } else if (i > 1 && previous_image_disposal_method == ImageDescriptor::DisposalMethod::RestorePrevious) { - copy_frame(*image.bitmap, *context.images.at(i - 2).bitmap); + // TODO: tricky as it potentially requires remembering _all_ previous frames. + // Luckily it seems GIFs with this mode are rare in the wild. } int pixel_index = 0; @@ -345,7 +344,7 @@ static bool decode_frames_up_to_index(GIFLoadingContext& context, size_t frame_i } if (!image.transparent || previous_image_disposal_method == ImageDescriptor::DisposalMethod::None || color != image.transparency_index) { - image.bitmap->set_pixel(x, y, c); + context.frame_buffer->set_pixel(x, y, c); } ++pixel_index; @@ -363,10 +362,11 @@ static bool decode_frames_up_to_index(GIFLoadingContext& context, size_t frame_i } } } - - ++context.frames_decoded; } + context.current_frame = frame_index; + context.state = GIFLoadingContext::State::FrameComplete; + return true; } @@ -610,27 +610,25 @@ IntSize GIFImageDecoderPlugin::size() RefPtr<Gfx::Bitmap> GIFImageDecoderPlugin::bitmap() { - return frame(0).image; + if (m_context->state < GIFLoadingContext::State::FrameComplete) { + return frame(0).image; + } + return m_context->frame_buffer; } void GIFImageDecoderPlugin::set_volatile() { - for (size_t i = 0; i < m_context->frames_decoded; ++i) { - m_context->images.at(i).bitmap->set_volatile(); + if (m_context->frame_buffer) { + m_context->frame_buffer->set_volatile(); } } bool GIFImageDecoderPlugin::set_nonvolatile() { - if (m_context->images.is_empty()) { - return false; - } - - bool success = true; - for (size_t i = 0; i < m_context->frames_decoded; ++i) { - success &= m_context->images.at(i).bitmap->set_nonvolatile(); + if (!m_context->frame_buffer) { + return true; } - return success; + return m_context->frame_buffer->set_nonvolatile(); } bool GIFImageDecoderPlugin::sniff() @@ -689,13 +687,13 @@ ImageFrameDescriptor GIFImageDecoderPlugin::frame(size_t i) } } - if (!decode_frames_up_to_index(*m_context, i)) { + if (!decode_frame(*m_context, i)) { m_context->state = GIFLoadingContext::State::Error; return {}; } ImageFrameDescriptor frame {}; - frame.image = m_context->images.at(i).bitmap; + frame.image = m_context->frame_buffer; frame.duration = m_context->images.at(i).duration * 10; if (frame.duration <= 10) { |