fix bug that grayscale png is mistakely processed

This commit is contained in:
Jinhao 2019-04-24 01:18:27 +08:00
parent b9ab3f8a4f
commit ec38e666a1

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@ -30,16 +30,21 @@ namespace nana
png_byte color_type = ::png_get_color_type(png_ptr, info_ptr); png_byte color_type = ::png_get_color_type(png_ptr, info_ptr);
const auto bit_depth = ::png_get_bit_depth(png_ptr, info_ptr); const auto bit_depth = ::png_get_bit_depth(png_ptr, info_ptr);
pixbuf_.open(png_width, png_height);
//do some extra work for palette/gray color type //do some extra work for palette/gray color type
if (PNG_COLOR_TYPE_PALETTE == color_type) if (PNG_COLOR_TYPE_PALETTE == color_type)
::png_set_palette_to_rgb(png_ptr); ::png_set_palette_to_rgb(png_ptr);
else if ((PNG_COLOR_TYPE_GRAY == color_type) && (bit_depth < 8)) else if ((PNG_COLOR_TYPE_GRAY == color_type) || (PNG_COLOR_TYPE_GRAY_ALPHA == color_type))
::png_set_gray_to_rgb(png_ptr); ::png_set_gray_to_rgb(png_ptr);
auto is_alpha_enabled = (::png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) != 0); auto is_alpha_enabled = (::png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) != 0);
if (is_alpha_enabled) if (is_alpha_enabled)
::png_set_tRNS_to_alpha(png_ptr); ::png_set_tRNS_to_alpha(png_ptr);
is_alpha_enabled |= ((PNG_COLOR_MASK_ALPHA & color_type) != 0);
pixbuf_.alpha_channel(is_alpha_enabled);
//make sure 8-bit per channel //make sure 8-bit per channel
if (16 == bit_depth) if (16 == bit_depth)
::png_set_strip_16(png_ptr); ::png_set_strip_16(png_ptr);
@ -51,11 +56,6 @@ namespace nana
png_bytep * row_ptrs = new png_bytep[png_height]; png_bytep * row_ptrs = new png_bytep[png_height];
const std::size_t png_rowbytes = ::png_get_rowbytes(png_ptr, info_ptr); const std::size_t png_rowbytes = ::png_get_rowbytes(png_ptr, info_ptr);
pixbuf_.open(png_width, png_height);
is_alpha_enabled |= ((PNG_COLOR_MASK_ALPHA & color_type) != 0);
pixbuf_.alpha_channel(is_alpha_enabled);
if (is_alpha_enabled && (png_rowbytes == png_width * sizeof(pixel_argb_t))) if (is_alpha_enabled && (png_rowbytes == png_width * sizeof(pixel_argb_t)))
{ {
for (int i = 0; i < png_height; ++i) for (int i = 0; i < png_height; ++i)
@ -63,6 +63,8 @@ namespace nana
::png_read_image(png_ptr, row_ptrs); ::png_read_image(png_ptr, row_ptrs);
if (std::is_same<pixel_argb_t, pixel_color_t>::value)
{
for (int i = 0; i < png_height; ++i) for (int i = 0; i < png_height; ++i)
{ {
auto p = pixbuf_.raw_ptr(i); auto p = pixbuf_.raw_ptr(i);
@ -74,6 +76,7 @@ namespace nana
} }
} }
} }
}
else else
{ {
png_byte * png_pixbuf = new png_byte[png_height * png_rowbytes]; png_byte * png_pixbuf = new png_byte[png_height * png_rowbytes];
@ -82,7 +85,6 @@ namespace nana
row_ptrs[i] = reinterpret_cast<png_bytep>(png_pixbuf + png_rowbytes * i); row_ptrs[i] = reinterpret_cast<png_bytep>(png_pixbuf + png_rowbytes * i);
::png_read_image(png_ptr, row_ptrs); ::png_read_image(png_ptr, row_ptrs);
//::png_destroy_read_struct(&png_ptr, &info_ptr, 0);
std::size_t png_pixel_bytes = png_rowbytes / png_width; std::size_t png_pixel_bytes = png_rowbytes / png_width;