package com.loomcom.symon;
import com.loomcom.symon.devices.Crtc;
import com.loomcom.symon.devices.DeviceChangeListener;
import com.loomcom.symon.devices.Memory;
import com.loomcom.symon.exceptions.MemoryAccessException;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.runners.MockitoJUnitRunner;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.*;
@RunWith(MockitoJUnitRunner.class)
public class CrtcTest {
Crtc crtc;
Memory memory;
@Mock
DeviceChangeListener changeListener;
@Before
public void createDevices() throws Exception {
memory = new Memory(0, 0x7fff);
crtc = new Crtc(0x9000, memory);
crtc.registerListener(changeListener);
}
@Test
public void selectingRegisterDoesNotTriggedrCallback() throws Exception {
crtc.write(0, 1);
verify(changeListener, never()).deviceStateChanged();
}
@Test
public void shouldChangeHorizontalDisplayed() throws Exception {
crtc.write(0, 1);
crtc.write(1, 80);
assertEquals(80, crtc.getHorizontalDisplayed());
crtc.write(1, 40);
assertEquals(40, crtc.getHorizontalDisplayed());
}
@Test
public void changeHorizontalDisplayedShouldTriggerCallback() throws Exception {
crtc.write(0, 1);
crtc.write(1, 80);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test
public void shouldChangeVerticalDisplayed() throws Exception {
crtc.write(0, 6);
crtc.write(1, 23);
assertEquals(23, crtc.getVerticalDisplayed());
crtc.write(1, 26);
assertEquals(26, crtc.getVerticalDisplayed());
}
@Test
public void changeVerticalDisplayedShouldTriggerCallback() throws Exception {
crtc.write(0, 6);
crtc.write(1, 23);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test
public void shouldChangeScanLinesPerRow() throws Exception {
crtc.write(0, 9); // Select register 9, Scan Line
crtc.write(1, 3);
assertEquals(3, crtc.getScanLinesPerRow());
crtc.write(1, 5);
assertEquals(5, crtc.getScanLinesPerRow());
crtc.write(1, 9);
assertEquals(9, crtc.getScanLinesPerRow());
}
@Test
public void changeScanLinesPerRowShouldTriggerCallback() throws Exception {
crtc.write(0, 9); // Select register 9, Scan Line
crtc.write(1, 3);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test
public void shouldChangeCursorStartLine() throws Exception {
crtc.write(0, 10);
crtc.write(1, 0);
assertEquals(0, crtc.getCursorStartLine());
crtc.write(1, 1);
assertEquals(1, crtc.getCursorStartLine());
crtc.write(1, 4);
assertEquals(4, crtc.getCursorStartLine());
}
@Test
public void changeCursorStartLineShouldTriggerCallback() throws Exception {
crtc.write(0, 10);
crtc.write(1, 5);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test
public void cursorStartLineRegisterChangesCursorVisibility() throws Exception {
crtc.write(0, 10);
crtc.write(1, 0x00); // Start line 0, no blinking.
assertEquals(0, crtc.getCursorStartLine());
assertEquals(0, crtc.getCursorBlinkRate());
assertTrue(crtc.isCursorEnabled());
crtc.write(1, 0x23); // Start line 3, no cursor.
assertEquals(3, crtc.getCursorStartLine());
assertEquals(0, crtc.getCursorBlinkRate());
assertFalse(crtc.isCursorEnabled());
}
@Test
public void cursorStartLineRegisterChangesCursorBlinkRate() throws Exception {
crtc.write(0, 10);
crtc.write(1, 0x40); // Start line 0, 500ms blink delay
assertEquals(0, crtc.getCursorStartLine());
assertEquals(500, crtc.getCursorBlinkRate());
assertTrue(crtc.isCursorEnabled());
crtc.write(1, 0x62); // Start line 3, 1000ms blink delay
assertEquals(2, crtc.getCursorStartLine());
assertEquals(1000, crtc.getCursorBlinkRate());
assertTrue(crtc.isCursorEnabled());
}
@Test
public void shouldChangeCursorStopLine() throws Exception {
crtc.write(0, 11);
crtc.write(1, 0);
assertEquals(0, crtc.getCursorStopLine());
crtc.write(1, 3);
assertEquals(3, crtc.getCursorStopLine());
crtc.write(1, 6);
assertEquals(6, crtc.getCursorStopLine());
}
@Test
public void changeCursorStopLineShouldTriggerCallback() throws Exception {
crtc.write(0, 11);
crtc.write(1, 7);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test
public void shouldChangeScreenStartAddressHighByte() throws Exception {
crtc.write(0, 12);
crtc.write(1, 0x00);
assertEquals(0x00, crtc.getStartAddress() >> 8);
crtc.write(1, 0x30);
assertEquals(0x30, crtc.getStartAddress() >> 8);
crtc.write(1, 0x6f);
assertEquals(0x6f, crtc.getStartAddress() >> 8);
}
@Test
public void changeScreenStartAddressHighByteShouldTriggerCallback() throws Exception {
crtc.write(0, 12);
crtc.write(1, 0x30);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test
public void shouldChangeScreenStartAddressLowByte() throws Exception {
crtc.write(0, 13);
crtc.write(1, 0x00);
assertEquals(0x00, crtc.getStartAddress() & 0xff);
crtc.write(1, 0x11);
assertEquals(0x11, crtc.getStartAddress() & 0xff);
crtc.write(1, 0xff);
assertEquals(0xff, crtc.getStartAddress() & 0xff);
}
@Test
public void changeScreenStartAddressLowByteShouldTriggerCallback() throws Exception {
crtc.write(0, 13);
crtc.write(1, 0xff);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test(expected = MemoryAccessException.class)
public void shouldThrowMemoryAccessExceptionIfPageOutOfRange() throws Exception {
crtc.write(0, 12);
crtc.write(1, 0x7f); // Page of text will extend beyond 0x7fff
}
@Test
public void readingStartAddressShouldDoNothing() throws Exception {
crtc.write(0, 12); // High byte
crtc.write(1, 0x03);
assertEquals(0, crtc.read(1));
crtc.write(1, 0x70);
assertEquals(0, crtc.read(1));
crtc.write(0, 13); // Low byte
crtc.write(1, 0xff);
assertEquals(0, crtc.read(1));
crtc.write(1, 0x0e);
assertEquals(0, crtc.read(1));
}
@Test
public void shouldChangeCursorPositionHighByte() throws Exception {
crtc.write(0, 14); // Select register 14
crtc.write(1, 0x73); // Set high cursor byte to $73
assertEquals(0x73, crtc.getCursorPosition() >> 8);
crtc.write(1, 0x3f);
assertEquals(0x3f, crtc.getCursorPosition() >> 8);
crtc.write(1, 0x7f);
assertEquals(0x7f, crtc.getCursorPosition() >> 8);
}
@Test
public void shouldBeAbleToReadCursorPositionHighByte() throws Exception {
crtc.write(0, 14);
crtc.write(1, 0x3f);
assertEquals(0x3f, crtc.read(1));
crtc.write(1, 0x70);
assertEquals(0x70, crtc.read(1));
}
@Test
public void changeCursorPositionHighByteShouldTriggerCallback() throws Exception {
crtc.write(0, 14);
crtc.write(1, 0x73);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test
public void shouldChangeCursorPositionLowByte() throws Exception {
crtc.write(0, 15); // Select register 15
crtc.write(1, 0x00); // Set low cursor byte to $00
assertEquals(0x00, crtc.getCursorPosition() & 0xff);
crtc.write(1, 0x1f); // Set low cursor byte to $1f
assertEquals(0x1f, crtc.getCursorPosition() & 0xff);
crtc.write(1, 0xff); // Set low cursor byte to $ff
assertEquals(0xff, crtc.getCursorPosition() & 0xff);
}
@Test
public void shouldBeAbleToReadCursorPositionLowByte() throws Exception {
crtc.write(0, 15);
crtc.write(1, 0x00);
assertEquals(0x00, crtc.read(1));
crtc.write(1, 0x1f);
assertEquals(0x1f, crtc.read(1));
crtc.write(1, 0xff);
assertEquals(0xff, crtc.read(1));
}
@Test
public void changeCursorPositionLowByteShouldTriggerCallback() throws Exception {
crtc.write(0, 15);
crtc.write(1, 0x01);
verify(changeListener, times(1)).deviceStateChanged();
}
@Test(expected = MemoryAccessException.class)
public void shouldThrowMemoryAccessExceptionIfCursorGoesOutOfRange() throws Exception {
crtc.write(0, 14); // Select register 14
crtc.write(1, 0x80); // Can't position cursor
}
@Test
public void shouldSetRowColumnAddressing() throws Exception {
assertEquals(false, crtc.getRowColumnAddressing());
crtc.write(0, 8); // Select mode control register
crtc.write(1, 0x04);
assertEquals(true, crtc.getRowColumnAddressing());
}
@Test
public void shouldSetDisplayEnableSkew() throws Exception {
assertEquals(false, crtc.getDisplayEnableSkew());
crtc.write(0, 8); // Select mode control register
crtc.write(1, 0x10);
assertEquals(true, crtc.getDisplayEnableSkew());
}
@Test
public void shouldSetCursorSkew() throws Exception {
assertEquals(false, crtc.getCursorSkew());
crtc.write(0, 8); // Select mode control register
crtc.write(1, 0x20);
assertEquals(true, crtc.getCursorSkew());
}
@Test
public void shouldDoStraightBinaryAddressing() throws Exception {
crtc.write(0, 8);
crtc.write(1, 0); // Select straight binary addressing
// Fill the memory with a repeating pattern
int videoMemoryBase = 0x7000;
int j = 0;
for (int i = 0; i < 2048; i++) {
memory.write(videoMemoryBase + i, j);
if (j == 255) {
j = 0;
} else {
j++;
}
}
// Now verify that straight-binary addressing of the CRTC works
j = 0;
for (int i = 0; i < 2048; i++) {
assertEquals(j, crtc.getCharAtAddress(videoMemoryBase + i));
if (j == 255) {
j = 0;
} else {
j++;
}
}
}
}