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◆ main openmsx / src / video / BitmapConverter.hh
4.3 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#ifndef BITMAPCONVERTER_HH
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#define BITMAPCONVERTER_HH
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#include "DisplayMode.hh"
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#include <array>
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#include <cstdint>
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#include <span>
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namespace openmsx {
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/** Utility class for converting VRAM contents to host pixels.
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  */
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class BitmapConverter
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{
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public:
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	using Pixel = uint32_t;
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	using DPixel = uint64_t;
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	/** Create a new bitmap scanline converter.
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	  * @param palette16 Pointer to 2*16-entries array that specifies
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	  *   VDP color index to host pixel mapping.
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	  *   This is kept as a pointer, so any changes to the palette
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	  *   are immediately picked up by convertLine. Though to allow
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	  *   some internal optimizations, this class should be informed about
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	  *   changes in this array (not needed for the next two), see
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	  *   palette16Changed().
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	  *   Used for display modes Graphic4, Graphic5 and Graphic6.
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	  *   First 16 entries are for even pixels, next 16 are for odd pixels
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	  * @param palette256 Pointer to 256-entries array that specifies
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	  *   VDP color index to host pixel mapping.
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	  *   This is kept as a pointer, so any changes to the palette
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	  *   are immediately picked up by convertLine.
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	  *   Used for display mode Graphic7.
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	  * @param palette32768 Pointer to 32768-entries array that specifies
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	  *   VDP color index to host pixel mapping.
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	  *   This is kept as a pointer, so any changes to the palette
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	  *   are immediately picked up by convertLine.
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	  *   Used when YJK filter is active.
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	  */
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	BitmapConverter(std::span<const Pixel, 16 * 2> palette16,
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	                std::span<const Pixel, 256>    palette256,
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	                std::span<const Pixel, 32768>  palette32768);
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	/** Convert a line of V9938 VRAM to 256 or 512 host pixels.
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	  * Call this method in non-planar display modes (Graphic4 and Graphic5).
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	  * @param buf Buffer where host pixels will be written to.
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	  *            Depending on the screen mode, the buffer must contain at
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	  *            least 256 or 512 pixels, but more is allowed (the extra
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	  *            pixels aren't touched).
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	  * @param vramPtr Pointer to VRAM contents.
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	  */
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	void convertLine(std::span<Pixel> buf, std::span<const uint8_t, 128> vramPtr);
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	/** Convert a line of V9938 VRAM to 256 or 512 host pixels.
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	  * Call this method in planar display modes (Graphic6 and Graphic7).
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	  * @param buf Buffer where host pixels will be written to.
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	  *            Depending on the screen mode, the buffer must contain at
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	  *            least 256 or 512 pixels, but more is allowed (the extra
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	  *            pixels aren't touched).
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	  * @param vramPtr0 Pointer to VRAM contents, first plane.
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	  * @param vramPtr1 Pointer to VRAM contents, second plane.
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	  */
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	void convertLinePlanar(std::span<Pixel> buf,
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	                       std::span<const uint8_t, 128> vramPtr0,
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	                       std::span<const uint8_t, 128> vramPtr1);
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	/** Select the display mode to use for scanline conversion.
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	  * @param mode_ The new display mode.
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	  */
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	void setDisplayMode(DisplayMode mode_)
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	{
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		mode = mode_;
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	}
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	/** Inform this class about changes in the palette16 array.
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	  */
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	void palette16Changed()
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	{
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		dPaletteValid = false;
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	}
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private:
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	void calcDPalette();
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	void renderGraphic4(std::span<Pixel, 256> buf,
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	                    std::span<const uint8_t, 128> vramPtr0);
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	void renderGraphic5(std::span<Pixel, 512> buf,
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	                    std::span<const uint8_t, 128> vramPtr0) const;
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	void renderGraphic6(std::span<Pixel, 512> buf,
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	                    std::span<const uint8_t, 128> vramPtr0,
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	                    std::span<const uint8_t, 128> vramPtr1);
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	void renderGraphic7(std::span<Pixel, 256> buf,
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	                    std::span<const uint8_t, 128> vramPtr0,
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	                    std::span<const uint8_t, 128> vramPtr1) const;
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	void renderYJK(     std::span<Pixel, 256> buf,
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	                    std::span<const uint8_t, 128> vramPtr0,
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	                    std::span<const uint8_t, 128> vramPtr1) const;
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	void renderYAE(     std::span<Pixel, 256> buf,
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	                    std::span<const uint8_t, 128> vramPtr0,
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	                    std::span<const uint8_t, 128> vramPtr1) const;
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	void renderBogus(   std::span<Pixel, 256> buf) const;
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private:
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	std::span<const Pixel, 16 * 2> palette16;
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	std::span<const Pixel, 256>    palette256;
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	std::span<const Pixel, 32768>  palette32768;
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	std::array<DPixel, 16 * 16> dPalette;
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	DisplayMode mode;
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	bool dPaletteValid = false;
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};
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} // namespace openmsx
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#endif