Finally fixed the flicker bug introduced in the 2.0 code changes! Passes against various graphics demos without issues (thanks again, French Touch!)

README.md

@@ -14,7 +14,7 @@ Jace is a java-based Apple //e emulator with many compelling features:
 * MetaCheat also provides a live heat-map showing all RAM activity, color coded to indicate read, write or CPU execution -- Perfect for reverse engineers
 * Optional Debugging rom (][DB) can be enabled for a more powerful monitor
 * Super serial emulated as a tcp/ip port
-* Mockingboard support, partial Phasor support
+* Mockingboard and Phasor support
 * Highly flexible configuration allows any combination of cards and many extra options. You can even alter configuration while the emulation is running!
 
 ![Airheart](https://sites.google.com/site/brendanrobert/_/rsrc/1327073239228/projects/jace/airheart.png?height=250&width=400)

src/main/java/jace/apple2e/VideoNTSC.java

@@ -23,6 +23,7 @@ import jace.core.Computer;
 import jace.core.RAMEvent;
 import jace.core.RAMListener;
 import jace.core.Video;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
 import javafx.scene.image.PixelWriter;
@@ -69,6 +70,9 @@ public class VideoNTSC extends VideoDHGR {
     @Override
     protected void showBW(WritableImage screen, int x, int y, int dhgrWord) {
         int pos = divBy28[x];
+        if (rowStart < 0) {
+            rowStart = pos;
+        }
         colorActive[pos * 4] = colorActive[pos * 4 + 1] = colorActive[pos * 4 + 2] = colorActive[pos * 4 + 3] = false;
         scanline[pos] = dhgrWord;
     }
@@ -76,6 +80,9 @@ public class VideoNTSC extends VideoDHGR {
     @Override
     protected void showDhgr(WritableImage screen, int x, int y, int dhgrWord) {
         int pos = divBy28[x];
+        if (rowStart < 0) {
+            rowStart = pos;
+        }
         colorActive[pos * 4] = colorActive[pos * 4 + 1] = colorActive[pos * 4 + 2] = colorActive[pos * 4 + 3] = true;
         scanline[pos] = dhgrWord;
     }
@@ -83,6 +90,9 @@ public class VideoNTSC extends VideoDHGR {
     @Override
     protected void displayLores(WritableImage screen, int xOffset, int y, int rowAddress) {
         int pos = xOffset >> 1;
+        if (rowStart < 0) {
+            rowStart = pos;
+        }
         colorActive[xOffset * 2] = colorActive[xOffset * 2 + 1] = true;
         int data = ((RAM128k) computer.getMemory()).getMainMemory().readByte(rowAddress + xOffset) & 0x0FF;
         if ((xOffset & 1) == 0) {
@@ -108,6 +118,9 @@ public class VideoNTSC extends VideoDHGR {
     @Override
     protected void displayDoubleLores(WritableImage screen, int xOffset, int y, int rowAddress) {
         int pos = xOffset >> 1;
+        if (rowStart < 0) {
+            rowStart = pos;
+        }
         colorActive[xOffset * 2] = colorActive[xOffset * 2 + 1] = true;
         int c1 = ((RAM128k) computer.getMemory()).getAuxVideoMemory().readByte(rowAddress + xOffset) & 0x0FF;
         if ((y & 7) < 4) {
@@ -154,15 +167,15 @@ public class VideoNTSC extends VideoDHGR {
     }
 
     private void renderScanline(WritableImage screen, int y) {
-        PixelWriter writer = screen.getPixelWriter();
-            // This is equivilant to y*560 but is 5% faster
-        //int yOffset = ((y << 4) + (y << 5) + (y << 9))+xOffset;
-
-        // For some reason this jumps up to 40 in the wayout title screen (?)
         int p = 0;
-        if (rowStart > 0) {
-            getCurrentWriter().markDirty(y);
+        if (rowStart != 0) {
+//            getCurrentWriter().markDirty(y);
+            p = rowStart * 28;
+            if (rowStart < 0) {
+                return;
+            }
         }
+        PixelWriter writer = screen.getPixelWriter();
         // Reset scanline position
         int byteCounter = 0;
         for (int s = rowStart; s < 20; s++) {
@@ -209,6 +222,8 @@ public class VideoNTSC extends VideoDHGR {
 //                        }
 //                    }
         }
+        Arrays.fill(scanline, 0);
+        rowStart = -1;
     }
     // y Range [0,1]
     public static final double MIN_Y = 0;

src/main/java/jace/core/Video.java

@@ -130,15 +130,12 @@ public abstract class Video extends Device {
     @ConfigurableField(category = "video", name = "Min. Screen Refesh", defaultValue = "15", description = "Minimum number of miliseconds to wait before trying to redraw.")
     public static int MIN_SCREEN_REFRESH = 15;
 
+    Runnable redrawScreen = () -> {
+        visible.getPixelWriter().setPixels(0, 0, 560, 192, video.getPixelReader(), 0, 0);
+    };
     public void redraw() {
         screenDirty = false;
-        javafx.application.Platform.runLater(() -> {
-            visible.getPixelWriter().setPixels(0, 0, 560, 192, video.getPixelReader(), 0, 0);
-        });
-//        screen.drawImage(video, 0, 0, width, height, null);
-//        if (Emulator.getFrame() != null) {
-//            Emulator.getFrame().repaintIndicators();
-//        }
+        javafx.application.Platform.runLater(redrawScreen);
     }
 
     public void vblankStart() {
@@ -160,15 +157,15 @@ public abstract class Video extends Device {
         setFloatingBus(computer.getMemory().readRaw(scannerAddress + x));
         if (hPeriod > 0) {
             hPeriod--;
-            if (hPeriod == 0) {
+            if (hPeriod <= 1) {
                 x = -1;
                 setScannerLocation(currentWriter.getYOffset(y));
             }
         } else {
-            if (!isVblank && x < (APPLE_CYCLES_PER_LINE-1)) {
+            if (!isVblank && x < (APPLE_CYCLES_PER_LINE)) {
                 draw();
             }
-            if (x >= APPLE_CYCLES_PER_LINE - 1) {
+            if (x >= APPLE_CYCLES_PER_LINE) {
                 int yy = y + hblankOffsetY;
                 if (yy < 0) {
                     yy += APPLE_SCREEN_LINES;