implements time travel

firmware/src/Emulator/keyboard_defs.h

@@ -45,6 +45,9 @@ enum SpecKeys
   SPECKEY_M,
   SPECKEY_SYMB,
   SPECKEY_SPACE,
+  // indicates that everything above is not a normal key
+  SPECKEY_MAX_NORMAL,
+  // joystick keys
   JOYK_UP,
   JOYK_DOWN,
   JOYK_LEFT,

firmware/src/Emulator/spectrum.cpp

@@ -152,10 +152,12 @@ void ZXSpectrum::updateKey(SpecKeys key, uint8_t state)
       kempston_port &= 0b11101111;
     break;
   default:
-    if (state == 1)
-      speckey[key2specy[0][key]] &= key2specy[1][key];
-    else
-      speckey[key2specy[0][key]] |= ((key2specy[1][key]) ^ 0xFF);
+    if (key < SPECKEY_MAX_NORMAL) {
+      if (state == 1)
+        speckey[key2specy[0][key]] &= key2specy[1][key];
+      else
+        speckey[key2specy[0][key]] |= ((key2specy[1][key]) ^ 0xFF);
+    }
     break;
   }
 }

firmware/src/Screens/EmulatorScreen.cpp

@@ -115,7 +115,45 @@ void EmulatorScreen::updateKey(SpecKeys key, uint8_t state)
   //     Serial.printf("Audio file closed\n");
   //   }
   // }
-  machine->updateKey(key, state);
+  if (!isInTimeTravelMode)
+  {
+    machine->updateKey(key, state);
+  }
+}
+
+void EmulatorScreen::pressKey(SpecKeys key)
+{
+  if (key == SPECKEY_MENU)
+  {
+    // TODO show menu for save snapshot, load snapshot, time travel
+    if (!isInTimeTravelMode)
+    {
+      pause();
+      isInTimeTravelMode = true;
+      machine->startTimeTravel();
+      drawTimeTravel();
+    }
+    // showSaveSnapshotScreen();
+  } else if (isInTimeTravelMode)
+  {
+    // TODO cancel time travel
+    if (key == SPECKEY_ENTER)
+    {
+      machine->stopTimeTravel();
+      isInTimeTravelMode = false;
+      resume();
+    }
+    else
+    {
+      if (key == SPECKEY_5) {
+        machine->stepBack();
+      }
+      if (key == SPECKEY_8) {
+        machine->stepForward();
+      }
+      drawTimeTravel();
+    }
+  }
 }
 
 void EmulatorScreen::showSaveSnapshotScreen()
@@ -134,3 +172,23 @@ void EmulatorScreen::loadTape(std::string filename)
   machine->resume();
   isLoading = false;
 }
+
+void EmulatorScreen::drawTimeTravel() {
+    m_tft.fillRect(0, 0, m_tft.width(), 20, TFT_BLACK);
+
+    m_tft.loadFont(GillSans_15_vlw);
+    m_tft.setTextColor(TFT_WHITE, TFT_BLACK);
+
+    // Draw the left control "<5"
+    m_tft.drawString("<5", 5, 0);
+
+    // Draw the center text "Time Travel - Enter=Jump"
+    Point centerSize = m_tft.measureString("Time Travel - Enter=Jump");
+    int centerX = (m_tft.width() - centerSize.x) / 2;
+    m_tft.drawString("Time Travel - Enter=Jump", centerX, 0);
+
+    // Draw the right control "8>"
+    Point rightSize = m_tft.measureString("8>");
+    int rightX = m_tft.width() - rightSize.x - 5;  // 5 pixels from right edge
+    m_tft.drawString("8>", rightX, 0);
+}

firmware/src/Screens/EmulatorScreen.h

@@ -21,9 +21,12 @@ class EmulatorScreen : public Screen
     IFiles *m_files;
     void triggerLoadTape();
     bool isLoading = false;
+    bool isInTimeTravelMode = false;
+    void drawTimeTravel();
   public:
     EmulatorScreen(TFTDisplay &tft, AudioOutput *audioOutput, IFiles *files);
     void updateKey(SpecKeys key, uint8_t state);
+    void pressKey(SpecKeys key);
     void run(std::string filename, models_enum model);
     void pause();
     void resume();

firmware/src/Screens/EmulatorScreen/Machine.h

@@ -5,6 +5,7 @@
 #include <list>
 #include <vector>
 #include <deque>
+#include "Renderer.h"
 #include "../../Emulator/spectrum.h"
 #include "../../Serial.h"
 
@@ -23,9 +24,14 @@ struct MemoryBank {
 };
 
 struct TimeTravelInstant {
+  // the current memory pages
+  uint8_t hwBank = 0;
+  // the memory banks
   std::vector<MemoryBank *> memoryBanks;
+  // the z80 registers
   Z80Regs z80Regs;
-  uint8_t borderColors[32] = {0};
+  // the border colors
+  uint8_t borderColors[312] = {0};
 };
 
 class TimeTravel {
@@ -92,7 +98,9 @@ class TimeTravel {
     // copy the z80 registers
     memcpy(&instant->z80Regs, machine->z80Regs, sizeof(Z80Regs));
     // copy the border colors
-    memcpy(instant->borderColors, machine->borderColors, 32);
+    memcpy(instant->borderColors, machine->borderColors, 312);
+    // make sure the correct paging is set
+    instant->hwBank = machine->mem.hwBank;
     // add the instant to the list
     timeTravelInstants.push_back(instant);
     // if we have more than 30 seconds of time travel, remove the oldest instant
@@ -112,12 +120,14 @@ class TimeTravel {
     TimeTravelInstant *instant = timeTravelInstants[index];
     // copy the memory banks
     for (MemoryBank *memoryBank : instant->memoryBanks) {
-      memcpy(machine->mem.mappedMemory[memoryBank->index], memoryBank->data, 0x4000);
+      memcpy(machine->mem.banks[memoryBank->index]->data, memoryBank->data, 0x4000);
     }
     // copy the z80 registers
     memcpy(machine->z80Regs, &instant->z80Regs, sizeof(Z80Regs));
     // copy the border colors
-    memcpy(machine->borderColors, instant->borderColors, 32);
+    memcpy(machine->borderColors, instant->borderColors, 312);
+    // make sure the correct paging is set
+    machine->mem.page(instant->hwBank, true);
   }
   // remove everything from this point in time
   void reset(int index) {
@@ -151,6 +161,8 @@ class Machine {
     uint32_t cycleCount = 0;
     // time travel
     TimeTravel *timeTravel;
+    // current time travel position
+    int timeTravelPosition = 0;
     // callback for when rom loading routine is hit
     std::function<void()> romLoadingRoutineHitCallback;
   public:
@@ -164,6 +176,31 @@ class Machine {
     void resume() {
       isRunning = true;
     }
+    void startTimeTravel() {
+      // record the current state
+      timeTravel->record(machine);
+      timeTravelPosition = timeTravel->size() - 1;
+      Serial.printf("Starting time travel %d\n", timeTravelPosition);
+    }
+    void stepBack() {
+      if (timeTravelPosition > 0) {
+        timeTravelPosition--;
+        timeTravel->rewind(machine, timeTravelPosition);
+        renderer->forceRedraw(machine->mem.currentScreen->data, machine->borderColors);
+        Serial.printf("Time travel %d\n", timeTravelPosition);
+      }
+    }
+    void stepForward() {
+      if (timeTravelPosition < timeTravel->size() - 1) {
+        timeTravelPosition++;
+        timeTravel->rewind(machine, timeTravelPosition);
+        renderer->forceRedraw(machine->mem.currentScreen->data, machine->borderColors);
+        Serial.printf("Time travel %d\n", timeTravelPosition);
+      }
+    }
+    void stopTimeTravel() {
+      timeTravel->reset(timeTravelPosition);
+    }
     ZXSpectrum *getMachine() {
       return machine;
     }

firmware/src/Screens/EmulatorScreen/Renderer.h

@@ -103,4 +103,10 @@ class Renderer {
     void setNeedsRedraw() {
       firstDraw = true;
     }
+    void forceRedraw(const uint8_t *currentScreen, const uint8_t *borderColors) {
+      memcpy(currentScreenBuffer, currentScreen, 6912);
+      memcpy(currentBorderColors, borderColors, 312);
+      firstDraw = true;
+      drawScreen();
+    }
 };

firmware/src/Screens/NavigationStack.h

@@ -2,12 +2,15 @@
 
 #include <vector>
 #include "Screen.h"
+#include "../TFT/TFTDisplay.h"
 
 class NavigationStack
 {
+  private:
+    TFTDisplay *m_tft;
   public:
     std::vector<Screen *> stack;
-    NavigationStack() {}
+    NavigationStack(TFTDisplay *tft) : m_tft(tft) {}
     ~NavigationStack() {}
     Screen *getTop() {
       if (stack.size() > 0) {
@@ -51,5 +54,9 @@ class NavigationStack
       if (top) {
         top->pressKey(key);
       }
+      // TODO: Add some combination of keys to save a screenshot
+      // if (key == SPECKEY_MENU) {
+      //   m_tft->saveScreenshot();
+      // }
     };
 };

firmware/src/TFT/TFTDisplay.cpp

@@ -152,6 +152,8 @@ void TFTDisplay::sendTransaction(SPITransactionInfo *trans)
 
 void TFTDisplay::sendPixels(const uint16_t *data, int numPixels)
 {
+  writePixelsToFrameBuffer(data, numPixels);
+
   int bytes = numPixels * 2;
   for (uint32_t i = 0; i < bytes; i += DMA_BUFFER_SIZE)
   {
@@ -175,6 +177,7 @@ void TFTDisplay::sendData(const uint8_t *data, int length)
 
 void TFTDisplay::sendColor(uint16_t color, int numPixels)
 {
+  writePixelsToFrameBuffer(color, numPixels);
   for (int i = 0; i < numPixels; i += DMA_BUFFER_SIZE >> 1)
   {
     int len = std::min(numPixels - i, int(DMA_BUFFER_SIZE >> 1));
@@ -186,6 +189,15 @@ void TFTDisplay::sendColor(uint16_t color, int numPixels)
 
 void TFTDisplay::setWindow(int32_t x0, int32_t y0, int32_t x1, int32_t y1)
 {
+  // store the window for future frame buffer updates
+  windowX0 = x0;
+  windowY0 = y0;
+  windowX1 = x1;
+  windowY1 = y1;
+  currentX = x0;
+  currentY = y0;
+
+  // do the TFT window set
   uint8_t data[4];
   #ifdef TFT_X_OFFSET
   x0+=TFT_X_OFFSET;