V9990VRAM.hh

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#ifndef V9990VRAM_HH
#define V9990VRAM_HH
 
#include "V9990CmdEngine.hh"
#include "TrackedRam.hh"
#include "EmuTime.hh"
#include "openmsx.hh"
 
namespace openmsx {
 
class V9990;
 
class V9990VRAM
{
public:
        static constexpr unsigned VRAM_SIZE = 512 * 1024; // 512kB
 
        V9990VRAM(V9990& vdp, EmuTime::param time);
 
        void clear();
 
        inline void sync(EmuTime::param time) {
                cmdEngine->sync(time);
        }
 
        [[nodiscard]] static inline unsigned transformBx(unsigned address) {
                return ((address & 1) << 18) | ((address & 0x7FFFE) >> 1);
        }
        [[nodiscard]] static inline unsigned transformP1(unsigned address) {
                return address;
        }
        [[nodiscard]] static inline unsigned transformP2(unsigned address) {
                // Verified on a real Graphics9000
                if (address < 0x78000) {
                        return transformBx(address);
                } else if (address < 0x7C000) {
                        return address - 0x3C000;
                } else {
                        return address;
                }
        }
 
        [[nodiscard]] inline byte readVRAMBx(unsigned address) {
                return data[transformBx(address)];
        }
        [[nodiscard]] inline byte readVRAMP1(unsigned address) {
                return data[transformP1(address)];
        }
        [[nodiscard]] inline byte readVRAMP2(unsigned address) {
                return data[transformP2(address)];
        }
 
        inline void writeVRAMBx(unsigned address, byte value) {
                data.write(transformBx(address), value);
        }
        inline void writeVRAMP1(unsigned address, byte value) {
                data.write(transformP1(address), value);
        }
        inline void writeVRAMP2(unsigned address, byte value) {
                data.write(transformP2(address), value);
        }
 
        [[nodiscard]] inline byte readVRAMDirect(unsigned address) {
                return data[address];
        }
        inline void writeVRAMDirect(unsigned address, byte value) {
                data.write(address, value);
        }
 
        [[nodiscard]] byte readVRAMCPU(unsigned address, EmuTime::param time);
        void writeVRAMCPU(unsigned address, byte val, EmuTime::param time);
 
        void setCmdEngine(V9990CmdEngine& cmdEngine_) { cmdEngine = &cmdEngine_; }
 
        template<typename Archive>
        void serialize(Archive& ar, unsigned version);
 
private:
        unsigned mapAddress(unsigned address);
 
private:
        V9990& vdp;
 
        V9990CmdEngine* cmdEngine;
 
        TrackedRam data;
};
 
} // namespace openmsx
 
#endif