VDP.hh

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#ifndef VDP_HH
#define VDP_HH

#include "MSXDevice.hh"
#include "Schedulable.hh"
#include "VideoSystemChangeListener.hh"
#include "SimpleDebuggable.hh"
#include "TclCallback.hh"
#include "InfoTopic.hh"
#include "IRQHelper.hh"
#include "Clock.hh"
#include "DisplayMode.hh"
#include "Observer.hh"
#include "openmsx.hh"
#include "outer.hh"
#include <memory>
#include <array>

namespace openmsx {

class PostProcessor;
class Renderer;
class VDPCmdEngine;
class VDPVRAM;
class MSXCPU;
class SpriteChecker;
class Display;
class RawFrame;
class Setting;
template<typename> class EnumSetting;
namespace VDPAccessSlots {
        enum Delta : int;
        class Calculator;
}

class VDP final : public MSXDevice, private VideoSystemChangeListener
                , private Observer<Setting>
{
public:
        static constexpr int TICKS_PER_SECOND = 3579545 * 6; // 21.5MHz;
        using VDPClock = Clock<TICKS_PER_SECOND>;

        static constexpr int TICKS_PER_LINE = 1368;

        explicit VDP(const DeviceConfig& config);
        ~VDP() override;

        void powerUp(EmuTime::param time) override;
        void reset(EmuTime::param time) override;
        byte readIO(word port, EmuTime::param time) override;
        byte peekIO(word port, EmuTime::param time) const override;
        void writeIO(word port, byte value, EmuTime::param time) override;

        PostProcessor* getPostProcessor() const;

        inline bool isMSX1VDP() const {
                return (version & VM_MSX1) != 0;
        }

        inline bool isVDPwithPALonly() const {
                return (version & VM_PAL) != 0;
        }

        inline bool vdpLacksMirroring() const {
                return (version & VM_NO_MIRRORING) != 0;
        }

        inline bool vdpHasPatColMirroring() const {
                return (version & VM_PALCOL_MIRRORING) != 0;
        }

        inline bool isVDPwithVRAMremapping() const {
                return (version & VM_VRAM_REMAPPING) != 0;
        }

        inline bool hasYJK() const {
                return (version & VM_YJK) != 0;
        }

        std::array<std::array<uint8_t, 3>, 16> getMSX1Palette() const;

        inline DisplayMode getDisplayMode() const {
                return displayMode;
        }

        inline VDPVRAM& getVRAM() {
                return *vram;
        }

        inline const RawFrame* isSuperimposing() const {
                // Note that bit 0 of r#0 has no effect on an V9938 or higher,
                // but this bit is masked out. Also note that on an MSX1, if
                // bit 0 of r#0 is enabled and there is no external video
                // source, then we lose sync.
                // Also note that because this property is fixed per frame we
                // cannot (re)calculate it from register values.
                return superimposing;
        }

        inline SpriteChecker& getSpriteChecker() {
                return *spriteChecker;
        }

        inline bool getTransparency() const {
                return (controlRegs[8] & 0x20) == 0;
        }

        inline int getForegroundColor() const {
                return controlRegs[7] >> 4;
        }

        inline int getBackgroundColor() const {
                byte reg7 = controlRegs[7];
                if (displayMode.getByte() == DisplayMode::GRAPHIC7) {
                        return reg7;
                } else {
                        return reg7 & 0x0F;
                }
        }

        inline int getBlinkForegroundColor() const {
                return controlRegs[12] >> 4;
        }

        inline int getBlinkBackgroundColor() const {
                return controlRegs[12] & 0x0F;
        }

        inline bool getBlinkState() const {
                return blinkState;
        }

        inline word getPalette(int index) const {
                return palette[index];
        }

        inline bool isDisplayEnabled() const {
                return isDisplayArea && displayEnabled;
        }

        inline bool spritesEnabled() const {
                return displayEnabled &&
                       (displayMode.getSpriteMode(isMSX1VDP()) != 0) &&
                       ((controlRegs[8] & 0x02) == 0x00);
        }

        inline bool spritesEnabledFast() const {
                assert(displayMode.getSpriteMode(isMSX1VDP()) != 0);
                return displayEnabled && ((controlRegs[8] & 0x02) == 0x00);
        }

        inline bool spritesEnabledRegister() const {
                return (controlRegs[8] & 0x02) == 0x00;
        }

        inline byte getVerticalScroll() const {
                return controlRegs[23];
        }

        inline byte getHorizontalScrollLow() const {
                return controlRegs[27];
        }

        inline byte getHorizontalScrollHigh() const {
                return controlRegs[26];
        }

        inline bool isBorderMasked() const {
                return (controlRegs[25] & 0x02) != 0;
        }

        inline bool isMultiPageScrolling() const {
                return (controlRegs[25] & 0x01) && (controlRegs[2] & 0x20);
        }

        inline int getLineZero() const {
                return displayStart / TICKS_PER_LINE;
        }

        inline bool isPalTiming() const {
                return palTiming;
        }

        inline bool isInterlaced() const {
                return interlaced;
        }

        inline bool isFastBlinkEnabled() const {
                return (controlRegs[1] & 4) != 0;
        }

        inline bool isEvenOddEnabled() const {
                if (isFastBlinkEnabled()) return false;
                return (controlRegs[9] & 4) != 0;
        }

        inline bool getEvenOdd() const {
                return (statusReg2 & 2) != 0;
        }

        inline int getEvenOddMask() const {
                // TODO: Verify which page is displayed on even fields.
                assert(!isFastBlinkEnabled());
                return (((~controlRegs[9] & 4) << 6) | ((statusReg2 & 2) << 7)) &
                       (!blinkState << 8);
        }

        inline int getEvenOddMask(int line) const {
                if (isFastBlinkEnabled()) {
                        // EO and IL not considered in this mode
                        auto p = calculateLineBlinkState(line);
                        return (p.first) << 8;
                } else {
                        return getEvenOddMask();
                }
        }

        inline std::pair<bool, int> calculateLineBlinkState(unsigned line) const {
                assert(isFastBlinkEnabled());

                if (blinkCount == 0) { // not changing
                        return {blinkState, blinkCount};
                }

                unsigned evenLen = ((controlRegs[13] >> 4) & 0x0F) * 10;
                unsigned oddLen  = ((controlRegs[13] >> 0) & 0x0F) * 10;
                unsigned totalLen = evenLen + oddLen;
                assert(totalLen != 0); // because this implies 'blinkCount == 0'
                line %= totalLen; // reduce double flips

                bool resultState = blinkState; // initial guess, adjusted later
                if (blinkState) {
                        // We start in the 'even' period -> check first for
                        // even/odd transition, next for odd/even
                } else {
                        // We start in the 'odd' period -> do the opposite
                        std::swap(evenLen, oddLen);
                }
                int newCount = blinkCount - line;
                if (newCount <= 0) {
                        // switch even->odd    (or odd->even)
                        resultState = !resultState;
                        newCount += oddLen;
                        if (newCount <= 0) {
                                // switch odd->even   (or even->odd)
                                resultState = !resultState;
                                newCount += evenLen;
                                assert(newCount > 0);
                        }
                }
                return {resultState, newCount};
        }

        inline int getTicksThisFrame(EmuTime::param time) const {
                return frameStartTime.getTicksTill_fast(time);
        }

        inline EmuTime::param getFrameStartTime() const {
                return frameStartTime.getTime();
        }

        inline int getSpriteSize() const {
                return ((controlRegs[1] & 2) << 2) + 8;
        }

        inline bool isSpriteMag() const {
                return controlRegs[1] & 1;
        }

        inline bool getCmdBit() const {
                return (controlRegs[25] & 0x40) != 0;
        }

        inline int getLinesPerFrame() const {
                return palTiming ? 313 : 262;
        }

        inline int getTicksPerFrame() const {
                return getLinesPerFrame() * TICKS_PER_LINE;
        }

        inline bool isInsideFrame(EmuTime::param time) const {
                return time >= frameStartTime.getTime() &&
                        getTicksThisFrame(time) <= getTicksPerFrame();
        }

        inline int getHorizontalAdjust() const {
                return horizontalAdjust;
        }

        inline int getLeftSprites() const {
                return 100 + 102 + 56
                        + (horizontalAdjust - 7) * 4
                        + (displayMode.isTextMode() ? 36 : 0);
        }

        inline int getLeftBorder() const {
                return getLeftSprites() + (isBorderMasked() ? 8 * 4 : 0);
        }

        inline int getRightBorder() const {
                return getLeftSprites()
                        + (displayMode.isTextMode() ? 960 : 1024);
        }

        inline int getLeftBackground() const {
                return getLeftSprites() + getHorizontalScrollLow() * 4;
        }

        byte getStatusReg0() const { return statusReg0; }

        void setSpriteStatus(byte value)
        {
                statusReg0 = (statusReg0 & 0x80) | (value & 0x7F);
        }

        bool getVRMode() const {
                return (controlRegs[8] & 8) != 0;
        }

        void setExternalVideoSource(const RawFrame* externalSource) {
                externalVideo = externalSource;
        }

        bool getBrokenCmdTiming() const {
                return brokenCmdTiming;
        }

        EmuTime getAccessSlot(EmuTime::param time, VDPAccessSlots::Delta delta) const;

        VDPAccessSlots::Calculator getAccessSlotCalculator(
                EmuTime::param time, EmuTime::param limit) const;

        void scheduleCmdSync(EmuTime t) {
                auto now = getCurrentTime();
                if (t <= now) {
                        // The largest amount of VDP cycles between 'progress'
                        // in command emulation:
                        // - worst case the LMMM takes 120+64 cycles to fully process one pixel
                        // - the largest gap between access slots is 70 cycles
                        // - but if we're unlucky the CPU steals that slot
                        int LARGEST_STALL = 184 + 2 * 70;

                        t = now + VDPClock::duration(LARGEST_STALL);
                }
                syncCmdDone.setSyncPoint(t);
        }

        template<typename Archive>
        void serialize(Archive& ar, unsigned version);

private:
        void initTables();

        // VdpVersion bitmasks
        static constexpr unsigned VM_MSX1             =  1; // set-> MSX1,       unset-> MSX2 or MSX2+
        static constexpr unsigned VM_PAL              =  2; // set-> fixed PAL,  unset-> fixed NTSC or switchable
        static constexpr unsigned VM_NO_MIRRORING     =  4; // set-> no (screen2) mirroring
        static constexpr unsigned VM_PALCOL_MIRRORING =  8; // set-> pattern/color-table mirroring
        static constexpr unsigned VM_VRAM_REMAPPING   = 16; // set-> 4k,8/16k VRAM remapping
        static constexpr unsigned VM_TOSHIBA_PALETTE  = 32; // set-> has Toshiba palette
        static constexpr unsigned VM_YJK              = 64; // set-> has YJK (MSX2+)

        enum VdpVersion {
                TMS99X8A   = VM_MSX1 | VM_PALCOL_MIRRORING | VM_VRAM_REMAPPING,

                TMS9929A   = VM_MSX1 | VM_PALCOL_MIRRORING | VM_VRAM_REMAPPING | VM_PAL,

                TMS9129    = VM_MSX1 | VM_PAL,

                TMS91X8    = VM_MSX1,

                T6950PAL   = VM_MSX1 | VM_TOSHIBA_PALETTE | VM_NO_MIRRORING | VM_PAL,

                T6950NTSC  = VM_MSX1 | VM_TOSHIBA_PALETTE | VM_NO_MIRRORING,

                T7937APAL  = VM_MSX1 | VM_TOSHIBA_PALETTE | VM_PAL,

                T7937ANTSC = VM_MSX1 | VM_TOSHIBA_PALETTE,

                V9938      = 0,

                V9958      = VM_YJK,
        };

        struct SyncBase : public Schedulable {
                explicit SyncBase(VDP& vdp_) : Schedulable(vdp_.getScheduler()) {}
                using Schedulable::removeSyncPoint;
                using Schedulable::setSyncPoint;
                using Schedulable::pendingSyncPoint;
        protected:
                ~SyncBase() = default;
        };

        struct SyncVSync final : public SyncBase {
                explicit SyncVSync(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param time) override {
                        auto& vdp = OUTER(VDP, syncVSync);
                        vdp.execVSync(time);
                }
        } syncVSync;

        struct SyncDisplayStart final : public SyncBase {
                explicit SyncDisplayStart(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param time) override {
                        auto& vdp = OUTER(VDP, syncDisplayStart);
                        vdp.execDisplayStart(time);
                }
        } syncDisplayStart;

        struct SyncVScan final : public SyncBase {
                explicit SyncVScan(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param time) override {
                        auto& vdp = OUTER(VDP, syncVScan);
                        vdp.execVScan(time);
                }
        } syncVScan;

        struct SyncHScan final : public SyncBase {
                explicit SyncHScan(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param /*time*/) override {
                        auto& vdp = OUTER(VDP, syncHScan);
                        vdp.execHScan();
                }
        } syncHScan;

        struct SyncHorAdjust final : public SyncBase {
                explicit SyncHorAdjust(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param time) override {
                        auto& vdp = OUTER(VDP, syncHorAdjust);
                        vdp.execHorAdjust(time);
                }
        } syncHorAdjust;

        struct SyncSetMode final : public SyncBase {
                explicit SyncSetMode(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param time) override {
                        auto& vdp = OUTER(VDP, syncSetMode);
                        vdp.execSetMode(time);
                }
        } syncSetMode;

        struct SyncSetBlank final : public SyncBase {
                explicit SyncSetBlank(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param time) override {
                        auto& vdp = OUTER(VDP, syncSetBlank);
                        vdp.execSetBlank(time);
                }
        } syncSetBlank;

        struct SyncCpuVramAccess final : public SyncBase {
                explicit SyncCpuVramAccess(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param time) override {
                        auto& vdp = OUTER(VDP, syncCpuVramAccess);
                        vdp.execCpuVramAccess(time);
                }
        } syncCpuVramAccess;

        struct SyncCmdDone final : public SyncBase {
                explicit SyncCmdDone(VDP& vdp) : SyncBase(vdp) {}
                void executeUntil(EmuTime::param time) override {
                        auto& vdp = OUTER(VDP, syncCmdDone);
                        vdp.execSyncCmdDone(time);
                }
        } syncCmdDone;

        void execVSync(EmuTime::param time);
        void execDisplayStart(EmuTime::param time);
        void execVScan(EmuTime::param time);
        void execHScan();
        void execHorAdjust(EmuTime::param time);
        void execSetMode(EmuTime::param time);
        void execSetBlank(EmuTime::param time);
        void execCpuVramAccess(EmuTime::param time);
        void execSyncCmdDone(EmuTime::param time);

        inline int getNumberOfLines() const {
                return controlRegs[9] & 0x80 ? 212 : 192;
        }

        int getVerticalAdjust() const {
                return (controlRegs[18] >> 4) ^ 0x07;
        }

        inline bool getHR(int ticksThisFrame) const {
                // Note: These constants are located inside this function because
                //       GCC 4.0.x won't link if they are in the class scope.
                static constexpr int HBLANK_LEN_TXT = 404;
                static constexpr int HBLANK_LEN_GFX = 312;
                return
                        ( ticksThisFrame + TICKS_PER_LINE - getRightBorder()
                                ) % TICKS_PER_LINE
                        < (displayMode.isTextMode() ? HBLANK_LEN_TXT : HBLANK_LEN_GFX);
        }

        // VideoSystemChangeListener interface:
        void preVideoSystemChange() override;
        void postVideoSystemChange() override;

        void resetInit();

        void resetMasks(EmuTime::param time);

        void frameStart(EmuTime::param time);

        void scheduleDisplayStart(EmuTime::param time);

        void scheduleVScan(EmuTime::param time);

        void scheduleHScan(EmuTime::param time);

        void vramWrite(byte value, EmuTime::param time);

        byte vramRead(EmuTime::param time);

        void scheduleCpuVramAccess(bool isRead, byte write, EmuTime::param time);
        void executeCpuVramAccess(EmuTime::param time);

        byte peekStatusReg(byte reg, EmuTime::param time) const;
        byte readStatusReg(byte reg, EmuTime::param time);

        void changeRegister(byte reg, byte val, EmuTime::param time);

        void syncAtNextLine(SyncBase& type, EmuTime::param time);

        void createRenderer();

        void updateNameBase(EmuTime::param time);

        void updateColorBase(EmuTime::param time);

        void updatePatternBase(EmuTime::param time);

        void updateSpriteAttributeBase(EmuTime::param time);

        void updateSpritePatternBase(EmuTime::param time);

        void updateDisplayMode(DisplayMode newMode, bool cmdBit, EmuTime::param time);

        void setPalette(int index, word grb, EmuTime::param time);

        // Observer<Setting>
        void update(const Setting& setting) override;

private:
        Display& display;
        EnumSetting<bool>& cmdTiming;
        EnumSetting<bool>& tooFastAccess;

        struct RegDebug final : SimpleDebuggable {
                explicit RegDebug(VDP& vdp);
                byte read(unsigned address) override;
                void write(unsigned address, byte value, EmuTime::param time) override;
        } vdpRegDebug;

        struct StatusRegDebug final : SimpleDebuggable {
                explicit StatusRegDebug(VDP& vdp);
                byte read(unsigned address, EmuTime::param time) override;
        } vdpStatusRegDebug;

        struct PaletteDebug final : SimpleDebuggable {
                explicit PaletteDebug(VDP& vdp);
                byte read(unsigned address) override;
                void write(unsigned address, byte value, EmuTime::param time) override;
        } vdpPaletteDebug;

        struct VRAMPointerDebug final : SimpleDebuggable {
                explicit VRAMPointerDebug(VDP& vdp);
                byte read(unsigned address) override;
                void write(unsigned address, byte value, EmuTime::param time) override;
        } vramPointerDebug;

        class Info : public InfoTopic {
        public:
                void execute(span<const TclObject> tokens,
                             TclObject& result) const override;
                std::string help(const std::vector<std::string>& tokens) const override;
                virtual int calc(const EmuTime& time) const = 0;
        protected:
                Info(VDP& vdp_, const std::string& name, std::string helpText_);
                ~Info() = default;
                VDP& vdp;
                const std::string helpText;
        };

        struct FrameCountInfo final : Info {
                explicit FrameCountInfo(VDP& vdp);
                int calc(const EmuTime& time) const override;
        } frameCountInfo;

        struct CycleInFrameInfo final : Info {
                explicit CycleInFrameInfo(VDP& vdp);
                int calc(const EmuTime& time) const override;
        } cycleInFrameInfo;

        struct LineInFrameInfo final : Info {
                explicit LineInFrameInfo(VDP& vdp);
                int calc(const EmuTime& time) const override;
        } lineInFrameInfo;

        struct CycleInLineInfo final : Info {
                explicit CycleInLineInfo(VDP& vdp);
                int calc(const EmuTime& time) const override;
        } cycleInLineInfo;

        struct MsxYPosInfo final : Info {
                explicit MsxYPosInfo(VDP& vdp);
                int calc(const EmuTime& time) const override;
        } msxYPosInfo;

        struct MsxX256PosInfo final : Info {
                explicit MsxX256PosInfo(VDP& vdp);
                int calc(const EmuTime& time) const override;
        } msxX256PosInfo;

        struct MsxX512PosInfo final : Info {
                explicit MsxX512PosInfo(VDP& vdp);
                int calc(const EmuTime& time) const override;
        } msxX512PosInfo;

        std::unique_ptr<Renderer> renderer;

        std::unique_ptr<VDPCmdEngine> cmdEngine;

        std::unique_ptr<SpriteChecker> spriteChecker;

        std::unique_ptr<VDPVRAM> vram;

        const RawFrame* externalVideo;

        const RawFrame* superimposing;

        VDPClock frameStartTime;

        OptionalIRQHelper irqVertical;

        OptionalIRQHelper irqHorizontal;

        EmuTime displayStartSyncTime;

        EmuTime vScanSyncTime;

        EmuTime hScanSyncTime;

        TclCallback tooFastCallback;

        VdpVersion version;

        int saturationPr;

        int saturationPb;

        int frameCount;

        int displayStart;

        int horizontalScanOffset;

        int horizontalAdjust;

        byte controlRegs[32];

        int controlRegMask;

        byte controlValueMasks[32];

        int blinkCount;

        int vramPointer;

        word palette[16];

        bool isDisplayArea;

        bool palTiming;

        bool interlaced;

        byte statusReg0;

        byte statusReg1;

        byte statusReg2;

        bool blinkState;

        byte dataLatch;

        bool registerDataStored;

        bool paletteDataStored;

        byte cpuVramData;

        bool cpuVramReqIsRead;
        bool pendingCpuAccess; // always equal to pendingSyncPoint(CPU_VRAM_ACCESS)

        bool cpuExtendedVram;

        DisplayMode displayMode;

        bool displayEnabled;

        bool warningPrinted;

        bool brokenCmdTiming;
        bool allowTooFastAccess;

        MSXCPU& cpu;
        const byte fixedVDPIOdelayCycles;
};
SERIALIZE_CLASS_VERSION(VDP, 8);

} // namespace openmsx

#endif