Menu
▾
▴
[Jmol-commits] CVS: Jmol/src/org/openscience/jmol/g25d Graphics25D.java,1.7,1.8
|
From: Michael T H. <mic...@us...> - 2003-06-06 22:17:09
|
Update of /cvsroot/jmol/Jmol/src/org/openscience/jmol/g25d
In directory sc8-pr-cvs1:/tmp/cvs-serv10079/src/org/openscience/jmol/g25d
Modified Files:
Graphics25D.java
Log Message:
implemented cohen-sutherland line clipping
Index: Graphics25D.java
===================================================================
RCS file: /cvsroot/jmol/Jmol/src/org/openscience/jmol/g25d/Graphics25D.java,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -r1.7 -r1.8
--- Graphics25D.java 5 Jun 2003 22:42:08 -0000 1.7
+++ Graphics25D.java 6 Jun 2003 22:16:52 -0000 1.8
@@ -43,6 +43,7 @@
Image img;
Graphics g;
int width,height,size;
+ int xLast, yLast;
int[] pbuf;
short[] zbuf;
@@ -66,7 +67,6 @@
}
public void setEnabled(boolean value) {
- System.out.println("Graphics25D.setEnabled(" + value +")");
if (enabled != value) {
enabled = value;
setSize(width, height);
@@ -76,7 +76,9 @@
public void setSize(int width, int height) {
System.out.println("Graphics25D.setSize(" + width + "," + height + ")");
this.width = width;
+ xLast = width - 1;
this.height = height;
+ yLast = height - 1;
this.size = width * height;
if (g != null)
g.dispose();
@@ -301,12 +303,28 @@
g.drawLine(x1, y1, x2, y2);
return;
}
- if (x1 >= 0 && x1 < width && y1 >= 0 && y1 <= height &&
- x2 >= 0 && x2 < width && y2 >= 0 && y2 <= height) {
- plotLineDeltaUnclipped(x1, y1, z1, x2 - x1, y2 - y1, z2 - z1);
- } else {
- plotLineDeltaClipped(x1, y1, z1, x2 - x1, y2 - y1, z2 - z1);
+ int cc1 = clipCode(x1, y1);
+ int cc2 = clipCode(x2, y2);
+ while ((cc1 | cc2) != 0) {
+ if ((cc1 & cc2) != 0)
+ return;
+ int dx = x2 - x1;
+ int dy = y2 - y1;
+ if (cc1 != 0) { //cohen-sutherland line clipping
+ if ((cc1 & xLT) != 0) { y1 += (-x1 * dy) / dx; x1 = 0; }
+ else if ((cc1 & xGT) != 0) { y1 += ((xLast-x1)*dy) / dx; x1 = xLast; }
+ else if ((cc1 & yLT) != 0) { x1 += (-y1 * dx) / dy; y1 = 0; }
+ else { x1 += ((yLast-y1)*dx) / dy; y1 = yLast; }
+ cc1 = clipCode(x1, y1);
+ } else {
+ if ((cc2 & xLT) != 0) { y2 += (-x2 * dy) / dx; x2 = 0; }
+ else if ((cc2 & xGT) != 0) { y2 += ((xLast-x2)*dy) / dx; x2 = xLast; }
+ else if ((cc2 & yLT) != 0) { x2 += (-y2 * dx) / dy; y2 = 0; }
+ else { x2 += ((yLast-y2)*dx) / dy; y2 = yLast; }
+ cc2 = clipCode(x2, y2);
+ }
}
+ plotLineDeltaUnclipped(x1, y1, z1, x2 - x1, y2 - y1, z2 - z1);
}
public void drawPixel(int x, int y, int z) {
@@ -371,6 +389,24 @@
****************************************************************/
+ final static int xLT = 8;
+ final static int xGT = 4;
+ final static int yLT = 2;
+ final static int yGT = 1;
+
+ private final int clipCode(int x, int y) {
+ int code = 0;
+ if (x < 0)
+ code |= 8;
+ else if (x >= width)
+ code |= 4;
+ if (y < 0)
+ code |= 2;
+ else if (y >= height)
+ code |= 1;
+ return code;
+ }
+
void plotPixelClipped(int x, int y, int z) {
if (x < 0 || x >= width ||
y < 0 || y >= height
@@ -467,61 +503,6 @@
}
}
- void plotLineDeltaClipped(int x1, int y1, int z1, int dx, int dy, int dz) {
- int xCurrent = x1;
- int yCurrent = y1;
- int xIncrement = 1, yIncrement = 1;
-
- if (dx < 0) {
- dx = -dx;
- xIncrement = -1;
- }
- if (dy < 0) {
- dy = -dy;
- yIncrement = -1;
- }
- int twoDx = dx + dx, twoDy = dy + dy;
- plotPixelClipped(xCurrent, yCurrent, z1);
- if (dx == 0 && dy == 0)
- return;
- // the z dimension and the z increment are stored with a fractional
- // component in the bottom 10 bits.
- int zCurrentScaled = z1 << 10;
- if (dy <= dx) {
- int roundingFactor = dx - 1;
- if (dz < 0) roundingFactor = -roundingFactor;
- int zIncrementScaled = ((dz << 10) + roundingFactor) / dx;
- int twoDxAccumulatedYError = 0;
- int n = dx;
- do {
- xCurrent += xIncrement;
- zCurrentScaled += zIncrementScaled;
- twoDxAccumulatedYError += twoDy;
- if (twoDxAccumulatedYError > dx) {
- yCurrent += yIncrement;
- twoDxAccumulatedYError -= twoDx;
- }
- plotPixelClipped(xCurrent, yCurrent, zCurrentScaled >> 10);
- } while (--n > 0);
- return;
- }
- int roundingFactor = dy - 1;
- if (dy < 0) roundingFactor = -roundingFactor;
- int zIncrementScaled = ((dz << 10) + roundingFactor) / dy;
- int twoDyAccumulatedXError = 0;
- int n = dy;
- do {
- yCurrent += yIncrement;
- zCurrentScaled += zIncrementScaled;
- twoDyAccumulatedXError += twoDx;
- if (twoDyAccumulatedXError > dy) {
- xCurrent += xIncrement;
- twoDyAccumulatedXError -= twoDy;
- }
- plotPixelClipped(xCurrent, yCurrent, zCurrentScaled >> 10);
- } while (--n > 0);
- }
-
void plotLineDeltaUnclipped(int x1, int y1, int z1, int dx, int dy, int dz) {
int offset = y1 * width + x1;
if (z1 < zbuf[offset]) {
@@ -531,9 +512,11 @@
if (dx == 0 && dy == 0)
return;
- int xCurrent = x1;
- int yCurrent = y1;
- int xIncrement = 1, yIncrement = 1, yOffsetIncrement = width;
+ // int xCurrent = x1;
+ // int yCurrent = y1;
+ int xIncrement = 1;
+ // int yIncrement = 1;
+ int yOffsetIncrement = width;
if (dx < 0) {
dx = -dx;
@@ -541,7 +524,7 @@
}
if (dy < 0) {
dy = -dy;
- yIncrement = -1;
+ // yIncrement = -1;
yOffsetIncrement = -width;
}
int twoDx = dx + dx, twoDy = dy + dy;
@@ -556,12 +539,12 @@
int twoDxAccumulatedYError = 0;
int n = dx;
do {
- xCurrent += xIncrement;
+ // xCurrent += xIncrement;
offset += xIncrement;
zCurrentScaled += zIncrementScaled;
twoDxAccumulatedYError += twoDy;
if (twoDxAccumulatedYError > dx) {
- yCurrent += yIncrement;
+ // yCurrent += yIncrement;
offset += yOffsetIncrement;
twoDxAccumulatedYError -= twoDx;
}
@@ -579,12 +562,12 @@
int twoDyAccumulatedXError = 0;
int n = dy;
do {
- yCurrent += yIncrement;
+ // yCurrent += yIncrement;
offset += yOffsetIncrement;
zCurrentScaled += zIncrementScaled;
twoDyAccumulatedXError += twoDx;
if (twoDyAccumulatedXError > dy) {
- xCurrent += xIncrement;
+ // xCurrent += xIncrement;
offset += xIncrement;
twoDyAccumulatedXError -= twoDy;
}
|