C++ Reference::data方法代码示例

//! ---|> Window
void WindowSDL::doHideCursor() {
	static std::unique_ptr<Cursor> hiddenCursor;
	if(hiddenCursor.get() == nullptr) {
		Reference<Bitmap> bitmap = new Bitmap(1, 1);
		bitmap->data()[0] = 0;
		bitmap->data()[1] = 0;
		bitmap->data()[2] = 0;
		bitmap->data()[3] = 0;
		hiddenCursor = createCursor(bitmap, 0, 0);
	}
	doSetCursor(hiddenCursor.get());
}

Reference<Bitmap> StreamerPNG::loadBitmap(std::istream & input) {
	char header[8];
	input.read(header, 8);
	const int is_png = !png_sig_cmp(reinterpret_cast<png_byte *>(header), 0, 8);
	if(!is_png) {
		WARN("File is not a valid PNG image.");
		return nullptr;
	}

	// Set up the necessary structures for libpng.
	png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
	if(!png_ptr) {
		return nullptr;
	}

	png_infop info_ptr = png_create_info_struct(png_ptr);
	if(!info_ptr) {
		png_destroy_read_struct(&png_ptr, static_cast<png_infopp>(nullptr), static_cast<png_infopp>(nullptr));
		return nullptr;
	}

	if(setjmp(png_jmpbuf(png_ptr))) {
		png_destroy_read_struct(&png_ptr, &info_ptr, static_cast<png_infopp>(nullptr));
		return nullptr;
	}

	struct PNGFunctions {
			static void readData(png_structp read_ptr, png_bytep data, png_size_t length) {
				std::istream * in = reinterpret_cast<std::istream *>(png_get_io_ptr(read_ptr));
				if(in == nullptr || !in->good()) {
					png_error(read_ptr, "Error in input stream.");
				}
				in->read(reinterpret_cast<char *>(data), static_cast<std::streamsize>(length));
				if(in->gcount() != static_cast<std::streamsize>(length)) {
					png_error(read_ptr, "Requested amount of data could not be extracted from input stream");
				}
			}
	};

	png_set_read_fn(png_ptr, reinterpret_cast<png_voidp>(&input), PNGFunctions::readData);

	png_set_sig_bytes(png_ptr, 8);

	png_read_info(png_ptr, info_ptr);

	png_uint_32 width;
	png_uint_32 height;
	int bit_depth;
	int color_type;
	png_get_IHDR(	png_ptr, info_ptr,
					&width, &height,
					&bit_depth, &color_type, nullptr, nullptr, nullptr);

	PixelFormat pixelFormat = PixelFormat::RGB;
	switch(color_type) {
		case PNG_COLOR_TYPE_GRAY:
			// Convert bpp less than 8 to 8 bits.
			if(bit_depth < 8) {
				png_set_expand_gray_1_2_4_to_8(png_ptr);
			}
			pixelFormat = PixelFormat::MONO;
			break;
		case PNG_COLOR_TYPE_GRAY_ALPHA:
			// Convert grayscale with alpha to RGBA.
			png_set_expand(png_ptr);
			png_set_gray_to_rgb(png_ptr);
			pixelFormat = PixelFormat::RGBA;
			break;
		case PNG_COLOR_TYPE_PALETTE:
			// Convert color palette to RGB(A).
			png_set_expand(png_ptr);

			// Check if the color palette contains transparent colors.
#if PNG_LIBPNG_VER >= 10300
			if(png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)){
				pixelFormat = PixelFormat::RGBA;
			}
#else
			if(info_ptr->valid & PNG_INFO_tRNS) {
				pixelFormat = PixelFormat::RGBA;
			}
#endif
			break;
		case PNG_COLOR_TYPE_RGB_ALPHA:
			pixelFormat = PixelFormat::RGBA;
			break;
		default:
			// Already set to RGB above.
			break;
	}
	// Convert 16 bpp to 8 bits.
	if (bit_depth == 16) {
		png_set_strip_16(png_ptr);
	}

	// Create the bitmap to store the data.
	Reference<Bitmap> bitmap = new Bitmap(width, height, pixelFormat);

	auto row_pointers = new png_bytep[height];
	const uint8_t bytes = pixelFormat.getBytesPerPixel();
//.........这里部分代码省略.........