/* Copyright (c) 2010, Carl Burch. License information is located in the
* com.cburch.logisim.Main source code and at www.cburch.com/logisim/. */
package com.cburch.logisim.std.arith;
import java.awt.Color;
import java.awt.Graphics;
import java.util.Arrays;
import com.cburch.logisim.data.Attribute;
import com.cburch.logisim.data.AttributeOption;
import com.cburch.logisim.data.Attributes;
import com.cburch.logisim.data.BitWidth;
import com.cburch.logisim.data.Bounds;
import com.cburch.logisim.data.Location;
import com.cburch.logisim.data.Value;
import com.cburch.logisim.instance.Instance;
import com.cburch.logisim.instance.InstanceFactory;
import com.cburch.logisim.instance.InstancePainter;
import com.cburch.logisim.instance.InstanceState;
import com.cburch.logisim.instance.Port;
import com.cburch.logisim.instance.StdAttr;
import com.cburch.logisim.tools.key.BitWidthConfigurator;
public class Shifter extends InstanceFactory {
static final AttributeOption SHIFT_LOGICAL_LEFT
= new AttributeOption("ll", Strings.getter("shiftLogicalLeft"));
static final AttributeOption SHIFT_LOGICAL_RIGHT
= new AttributeOption("lr", Strings.getter("shiftLogicalRight"));
static final AttributeOption SHIFT_ARITHMETIC_RIGHT
= new AttributeOption("ar", Strings.getter("shiftArithmeticRight"));
static final AttributeOption SHIFT_ROLL_LEFT
= new AttributeOption("rl", Strings.getter("shiftRollLeft"));
static final AttributeOption SHIFT_ROLL_RIGHT
= new AttributeOption("rr", Strings.getter("shiftRollRight"));
static final Attribute<AttributeOption> ATTR_SHIFT
= Attributes.forOption("shift", Strings.getter("shifterShiftAttr"),
new AttributeOption[] { SHIFT_LOGICAL_LEFT, SHIFT_LOGICAL_RIGHT,
SHIFT_ARITHMETIC_RIGHT, SHIFT_ROLL_LEFT, SHIFT_ROLL_RIGHT });
private static final int IN0 = 0;
private static final int IN1 = 1;
private static final int OUT = 2;
public Shifter() {
super("Shifter", Strings.getter("shifterComponent"));
setAttributes(new Attribute[] {
StdAttr.WIDTH, ATTR_SHIFT
}, new Object[] {
BitWidth.create(8), SHIFT_LOGICAL_LEFT
});
setKeyConfigurator(new BitWidthConfigurator(StdAttr.WIDTH));
setOffsetBounds(Bounds.create(-40, -20, 40, 40));
setIconName("shifter.gif");
}
@Override
protected void configureNewInstance(Instance instance) {
configurePorts(instance);
instance.addAttributeListener();
}
@Override
protected void instanceAttributeChanged(Instance instance, Attribute<?> attr) {
if (attr == StdAttr.WIDTH) {
configurePorts(instance);
}
}
private void configurePorts(Instance instance) {
BitWidth dataWid = instance.getAttributeValue(StdAttr.WIDTH);
int data = dataWid == null ? 32 : dataWid.getWidth();
int shift = 1;
while ((1 << shift) < data) shift++;
Port[] ps = new Port[3];
ps[IN0] = new Port(-40, -10, Port.INPUT, data);
ps[IN1] = new Port(-40, 10, Port.INPUT, shift);
ps[OUT] = new Port( 0, 0, Port.OUTPUT, data);
ps[IN0].setToolTip(Strings.getter("shifterInputTip"));
ps[IN1].setToolTip(Strings.getter("shifterDistanceTip"));
ps[OUT].setToolTip(Strings.getter("shifterOutputTip"));
instance.setPorts(ps);
}
@Override
public void propagate(InstanceState state) {
// compute output
BitWidth dataWidth = state.getAttributeValue(StdAttr.WIDTH);
int bits = dataWidth == null ? 32 : dataWidth.getWidth();
Value vx = state.getPort(IN0);
Value vd = state.getPort(IN1);
Value vy; // y will by x shifted by d
if (vd.isFullyDefined() && vx.getWidth() == bits) {
int d = vd.toIntValue();
Object shift = state.getAttributeValue(ATTR_SHIFT);
if (d == 0) {
vy = vx;
} else if (vx.isFullyDefined()) {
int x = vx.toIntValue();
int y;
if (shift == SHIFT_LOGICAL_RIGHT) {
y = x >>> d;
} else if (shift == SHIFT_ARITHMETIC_RIGHT) {
if (d >= bits) d = bits - 1;
y = x >> d | ((x << (32 - bits)) >> (32 - bits + d));
} else if (shift == SHIFT_ROLL_RIGHT) {
if (d >= bits) d -= bits;
y = (x >>> d) | (x << (bits - d));
} else if (shift == SHIFT_ROLL_LEFT) {
if (d >= bits) d -= bits;
y = (x << d) | (x >>> (bits - d));
} else { // SHIFT_LOGICAL_LEFT
y = x << d;
}
vy = Value.createKnown(dataWidth, y);
} else {
Value[] x = vx.getAll();
Value[] y = new Value[bits];
if (shift == SHIFT_LOGICAL_RIGHT) {
if (d >= bits) d = bits;
System.arraycopy(x, d, y, 0, bits - d);
Arrays.fill(y, bits - d, bits, Value.FALSE);
} else if (shift == SHIFT_ARITHMETIC_RIGHT) {
if (d >= bits) d = bits;
System.arraycopy(x, d, y, 0, x.length - d);
Arrays.fill(y, bits - d, y.length, x[bits - 1]);
} else if (shift == SHIFT_ROLL_RIGHT) {
if (d >= bits) d -= bits;
System.arraycopy(x, d, y, 0, bits - d);
System.arraycopy(x, 0, y, bits - d, d);
} else if (shift == SHIFT_ROLL_LEFT) {
if (d >= bits) d -= bits;
System.arraycopy(x, x.length - d, y, 0, d);
System.arraycopy(x, 0, y, d, bits - d);
} else { // SHIFT_LOGICAL_LEFT
if (d >= bits) d = bits;
Arrays.fill(y, 0, d, Value.FALSE);
System.arraycopy(x, 0, y, d, bits - d);
}
vy = Value.create(y);
}
} else {
vy = Value.createError(dataWidth);
}
// propagate them
int delay = dataWidth.getWidth() * (3 * Adder.PER_DELAY);
state.setPort(OUT, vy, delay);
}
@Override
public void paintInstance(InstancePainter painter) {
Graphics g = painter.getGraphics();
painter.drawBounds();
painter.drawPorts();
Location loc = painter.getLocation();
int x = loc.getX() - 15;
int y = loc.getY();
Object shift = painter.getAttributeValue(ATTR_SHIFT);
g.setColor(Color.BLACK);
if (shift == SHIFT_LOGICAL_RIGHT) {
g.fillRect(x, y - 1, 8, 3);
drawArrow(g, x + 10, y, -4);
} else if (shift == SHIFT_ARITHMETIC_RIGHT) {
g.fillRect(x, y - 1, 2, 3);
g.fillRect(x + 3, y - 1, 5, 3);
drawArrow(g, x + 10, y, -4);
} else if (shift == SHIFT_ROLL_RIGHT) {
g.fillRect(x, y - 1, 5, 3);
g.fillRect(x + 8, y - 7, 2, 8);
g.fillRect(x, y - 7, 2, 8);
g.fillRect(x, y - 7, 10, 2);
drawArrow(g, x + 8, y, -4);
} else if (shift == SHIFT_ROLL_LEFT) {
g.fillRect(x + 6, y - 1, 4, 3);
g.fillRect(x + 8, y - 7, 2, 8);
g.fillRect(x, y - 7, 2, 8);
g.fillRect(x, y - 7, 10, 2);
drawArrow(g, x + 3, y, 4);
} else { // SHIFT_LOGICAL_LEFT
g.fillRect(x + 2, y - 1, 8, 3);
drawArrow(g, x, y, 4);
}
}
private void drawArrow(Graphics g, int x, int y, int d) {
int[] px = { x + d, x, x + d };
int[] py = { y + d, y, y - d };
g.fillPolygon(px, py, 3);
}
}