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[#314] zx-spectrum48k: ULA refresh based on CPU cycles
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@vbmacher
vbmacher committed Jan 28, 2023
1 parent 3d3fb5c commit e6a8dc6
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Showing 3 changed files with 57 additions and 34 deletions.
2 changes: 1 addition & 1 deletion plugins/cpu/z80-cpu/src/main/java/net/emustudio/plugins/cpu/zilogZ80/gui/StatusPanel.java
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Expand Up @@ -732,7 +732,7 @@ private void initComponents() {

jLabel31.setText("CPU Frequency:");

spnFrequency.setModel(new SpinnerNumberModel(20000, 1, null, 100));
spnFrequency.setModel(new SpinnerNumberModel(context.getCPUFrequency(), 1, null, 100));
spnFrequency.setName("CPU frequency");

jLabel33.setFont(jLabel33.getFont().deriveFont(jLabel33.getFont().getStyle() | java.awt.Font.BOLD));
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5 changes: 5 additions & 0 deletions ...zxspectrum-display/src/main/java/net/emustudio/plugins/device/zxspectrum/display/ULA.java
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Expand Up @@ -67,6 +67,11 @@ public ULA(MemoryContext<Byte> memory, Context8080 cpu) {
Arrays.fill(keymap, (byte) 0xFF);
}

// little hack..
public Context8080 getCpu() {
return cpu;
}

public void readScreen() {
for (int y = 0; y < SCREEN_HEIGHT; y++) {
for (int x = 0; x < SCREEN_WIDTH; x++) {
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84 changes: 51 additions & 33 deletions ...play/src/main/java/net/emustudio/plugins/device/zxspectrum/display/gui/DisplayCanvas.java
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Expand Up @@ -18,26 +18,37 @@
*/
package net.emustudio.plugins.device.zxspectrum.display.gui;

import net.emustudio.emulib.plugins.cpu.TimedEventsProcessor;
import net.emustudio.plugins.device.zxspectrum.display.ULA;

import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferStrategy;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicBoolean;

import static net.emustudio.plugins.device.zxspectrum.display.ULA.SCREEN_HEIGHT;
import static net.emustudio.plugins.device.zxspectrum.display.ULA.SCREEN_WIDTH;

// https://worldofspectrum.org/faq/reference/48kreference.htm
public class DisplayCanvas extends Canvas implements AutoCloseable {
// a frame is (64+192+56)*224=69888 T states long, which means that the '50 Hz' interrupt is actually
// a 3.5MHz/69888=50.08 Hz interrupt
private static final int REPAINT_CPU_TSTATES = 69888;

private static final int BORDER_WIDHT = 48; // pixels
private static final int X_GAP = 48; // pixels
private static final int Y_GAP = 48; // pixels

private static final Color FOREGROUND = new Color(255, 255, 255);
private static final Color BACKGROUND = Color.BLACK;

private final Timer repaintTimer;
private final AtomicBoolean painting = new AtomicBoolean(false);
private volatile Dimension size = new Dimension(0, 0);

private final ULA ula;
private final TimedEventsProcessor ted;
private final PaintCycle paintCycle = new PaintCycle();

public DisplayCanvas(ULA ula) {
this.ula = Objects.requireNonNull(ula);
Expand All @@ -47,19 +58,19 @@ public DisplayCanvas(ULA ula) {
Font textFont = new Font("Monospaced", Font.PLAIN, 14);
setFont(textFont);

PaintCycle paintCycle = new PaintCycle();
this.repaintTimer = new Timer(1000 / 50, e -> paintCycle.run()); // 50 HZ
this.repaintTimer.setCoalesce(true);
this.ted = ula.getCpu()
.getTimedEventsProcessor()
.orElseThrow(() -> new NoSuchElementException("The CPU does not provide TimedEventProcessor"));
}

public void start() {
if (painting.compareAndSet(false, true)) {
createBufferStrategy(2);
this.repaintTimer.restart();

ted.schedule(REPAINT_CPU_TSTATES, paintCycle);
}
}


@Override
public Dimension getPreferredSize() {
return this.size;
Expand All @@ -84,7 +95,7 @@ public void setBounds(Rectangle r) {

@Override
public void close() {
repaintTimer.stop();
ted.remove(REPAINT_CPU_TSTATES, paintCycle);
painting.set(false);
}

Expand All @@ -102,35 +113,42 @@ public void run() {

protected void paint() {
Dimension dimension = size;
try {
// The buffers in a buffer strategy are usually type VolatileImage, they may become lost.
// VolatileImage differs from other Image variants in that if possible, VolatileImage is stored in
// Video RAM. This means that instead of keeping the image in the system memory with everything else,
// it is kept on the memory local to the graphics card. This allows for much faster drawing-to and
// copying-from operations.
do {
do {
do {
Graphics2D graphics = (Graphics2D) strategy.getDrawGraphics();
graphics.setColor(BACKGROUND);
graphics.fillRect(0, 0, dimension.width, dimension.height);

graphics.setColor(FOREGROUND);
byte[][] memory = ula.videoMemory;
int screenX = 0;
for (int y = 0; y < SCREEN_HEIGHT; y++) {
for (int x = 0; x < SCREEN_WIDTH; x++) {
byte row = memory[x][y];
for (int i = 0; i < 8; i++) {
boolean bit = ((row << i) & 0x80) == 0x80;
if (bit) {
graphics.drawLine(32 + screenX + i, y, 32 + screenX + i, y);
}
Graphics2D graphics = (Graphics2D) strategy.getDrawGraphics();
graphics.setColor(BACKGROUND);
graphics.fillRect(0, 0, dimension.width, dimension.height);

graphics.setColor(FOREGROUND);
byte[][] memory = ula.videoMemory;
int screenX = 0;
for (int y = 0; y < SCREEN_HEIGHT; y++) {
for (int x = 0; x < SCREEN_WIDTH; x++) {
byte row = memory[x][y];
for (int i = 0; i < 8; i++) {
boolean bit = ((row << i) & 0x80) == 0x80;
if (bit) {
graphics.drawLine(
2*(X_GAP + BORDER_WIDHT) + 2*screenX + 2*i, 2*Y_GAP + 2*y,
2*(X_GAP + BORDER_WIDHT) + 2*screenX + 2*i + 1, 2*Y_GAP + 2*y);
graphics.drawLine(
2*(X_GAP + BORDER_WIDHT) + 2*screenX + 2*i, 2*Y_GAP + 2*y + 1,
2*(X_GAP + BORDER_WIDHT) + 2*screenX + 2*i + 1, 2*Y_GAP + 2*y + 1);
}
screenX += 8;
}
screenX = 0;
screenX += 8;
}
graphics.dispose();
} while (strategy.contentsRestored());
strategy.show();
} while (strategy.contentsLost());
} catch (Exception ignored) {
}
screenX = 0;
}
graphics.dispose();
} while (strategy.contentsRestored());
strategy.show();
} while (strategy.contentsLost());
}
}
}

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