diff options
| -rw-r--r-- | src/platform/graphics/cairo/CairoImageFactory.cpp | 52 |
1 files changed, 34 insertions, 18 deletions
diff --git a/src/platform/graphics/cairo/CairoImageFactory.cpp b/src/platform/graphics/cairo/CairoImageFactory.cpp index 8b09f172..99994226 100644 --- a/src/platform/graphics/cairo/CairoImageFactory.cpp +++ b/src/platform/graphics/cairo/CairoImageFactory.cpp @@ -14,6 +14,29 @@ bool IsPngHeader(const std::byte* buffer, int size) { return png_sig_cmp(reinterpret_cast<png_const_bytep>(buffer), 0, size) == 0; } +std::uint32_t Mul(std::uint32_t v, float a) { + if (a == 0.f) return v; + return static_cast<std::uint32_t>(v * a); +} + +std::uint32_t ConvertPngPixelToCairo(std::uint32_t source) { + unsigned char* source_bytes = reinterpret_cast<unsigned char*>(&source); + + std::uint32_t result = 0; + + std::uint32_t alpha = source_bytes[3]; + + float a = source_bytes[3] / 255.f; + + result |= alpha << 24; + + result |= Mul(static_cast<std::uint32_t>(source_bytes[0]), a) << 16; + result |= Mul(static_cast<std::uint32_t>(source_bytes[1]), a) << 8; + result |= Mul(static_cast<std::uint32_t>(source_bytes[2]), a); + + return result; +} + std::unique_ptr<CairoImage> DecodePng(CairoGraphicsFactory* factory, io::Stream* stream) { png_structp png_ptr = nullptr; @@ -69,16 +92,12 @@ std::unique_ptr<CairoImage> DecodePng(CairoGraphicsFactory* factory, auto cairo_surface_data = cairo_image_surface_get_data(cairo_surface); for (int row = 0; row < height; row++) { - auto row_p = row_pointers[row]; - auto cairo_row_data = cairo_surface_data + row * cairo_surface_stride; - memcpy(cairo_row_data, row_p, width * 4); + auto row_pointer = reinterpret_cast<std::uint32_t*>(row_pointers[row]); + auto cairo_row_data = reinterpret_cast<std::uint32_t*>( + cairo_surface_data + row * cairo_surface_stride); + for (int col = 0; col < width; col++) { - std::uint8_t* pixel = - reinterpret_cast<std::uint8_t*>(cairo_row_data + col * 4); - float alpha = pixel[0] / 255.f; - pixel[1] *= alpha; - pixel[2] *= alpha; - pixel[3] *= alpha; + cairo_row_data[col] = ConvertPngPixelToCairo(row_pointer[col]); } } @@ -88,7 +107,7 @@ std::unique_ptr<CairoImage> DecodePng(CairoGraphicsFactory* factory, } std::uint8_t Div(std::uint32_t v, float a) { - if (a == 0.f) return 255; + if (a == 0.f) return v; std::uint32_t temp = static_cast<std::uint32_t>(v / a); if (temp > 255) temp = 255; return temp; @@ -150,15 +169,12 @@ void EncodePng(cairo_surface_t* cairo_surface, io::Stream* stream) { buffer.resize(width * height * 4); for (int row = 0; row < height; row++) { - auto buffer_row = buffer.data() + row * width * 4; - auto cairo_row_data = cairo_surface_data + row * cairo_surface_stride; + auto buffer_row = + reinterpret_cast<std::uint32_t*>(buffer.data() + row * width * 4); + auto cairo_row_data = reinterpret_cast<std::uint32_t*>( + cairo_surface_data + row * cairo_surface_stride); for (int col = 0; col < width; col++) { - std::uint32_t* source_pixel = - reinterpret_cast<std::uint32_t*>(cairo_row_data + col * 4); - std::uint32_t* target_pixel = - reinterpret_cast<std::uint32_t*>(buffer_row + col * 4); - - *target_pixel = ConvertCairoPixelToPng(*source_pixel); + buffer_row[col] = ConvertCairoPixelToPng(cairo_row_data[col]); } } |