Polygons

From a089059af0f396f778df1b56e0e292416bc35d6b Mon Sep 17 00:00:00 2001 From: scuri Date: Sat, 22 May 2010 00:14:01 +0000 Subject: *** empty log message *** --- html/en/func/polygon.html | 85 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 58 insertions(+), 27 deletions(-) (limited to 'html/en/func') diff --git a/html/en/func/polygon.html b/html/en/func/polygon.html index 4ab5834..3a0b9c0 100644 --- a/html/en/func/polygon.html +++ b/html/en/func/polygon.html @@ -1,16 +1,11 @@ - + Polygons - @@ -66,6 +61,10 @@ canvas:Begin(mode: number) [in Lua] cdChord, Filled Polygons and cdText will be composed in a region for clipping. See Regions documentation. +

CD_PATH: creates a path composed of several primitives + that can be line draw, filled or used as clipping. Must call + cdCanvasPathSet to configure the action between sequences of + cdCanvasVertex.

Open, Closed and Filled Polygons

@@ -87,31 +86,63 @@ canvas:End() [in Lua]

Ends the polygon's definition and draws it.

-"PATH": allows to create - a complex path using CD primitives and then fill, stroke or clip using the - new path. Must be used with the following parameters:

"BEGIN" - creates a new empty path, must be the first call
cdCanvasPixel, cdCanvasLine, cdCanvasArc - add elements to the path - instead of drawing to the canvas
"FILL" - closes the path, and fills it with the current fill attributes, - then the path is discarded
"STROKE" - strokes the path with the current line attributes, then the - path is discarded
"CLOSESTROKE" - closes the path, and strokes it with the current line - attributes, then the path is discarded
"FILLSTROKE" - closes the path, and fills it with the current fill +
```
void cdCanvasPathSet(cdCanvas* canvas, int action); [in C]
+
+canvas:PathSet(action: number) [in Lua]
```
+ +
Configures the action between sequences of cdCanvasVertex. + action can be:
+
- CD_PATH_NEW - creates a new empty path. Useful if more than one + path is configured. cdCanvasBegin(CD_PATH) already creates + a new path.
- CD_PATH_MOVETO - moves the current position to the given coordinates. + Must be followed by 1 call to cdCanvasVertex, + cdfCanvasVertex, or wdCanvasVertex.
- CD_PATH_LINETO - adds a line to the path from the current position to + the given coordinates. The current position is updated to the given + coordinates. If there is no current position, nothing is connected and only + the current position is updated. Must be followed by 1 call to + cdCanvasVertex, cdfCanvasVertex, or + wdCanvasVertex.
- CD_PATH_ARC - adds an arc to the path. If there is a current position + adds also a line from the current position to the start of the arc. The end + of the arc becomes the current position. Must be followed by 3 calls to + cdCanvasVertex, cdfCanvasVertex, or + wdCanvasVertex. One for the center of the arc (xc,yc), one + for the bounding rectangle size (w,h), and one for the start and end angles + (angle1,angle2). Angles are in degrees. When using integer coordinates + angles must be multiplied by 1000.
- CD_PATH_CURVETO - adds a bezier curve to the path. If there is no + current position, the first point will be used twice. The end point becomes + the current position. Must be followed by 3 calls to cdCanvasVertex, + cdfCanvasVertex, or wdCanvasVertex. Must + be first control point (x1,y1) + second control point (x2,y2) + end point + (x3,y3).
- CD_PATH_CLOSE - adds a line to the path that connects the last point + with the first point of the path, closing it.
- CD_PATH_FILL - fills the path with the current fill attributes, + then the path is discarded.
- CD_PATH_STROKE - strokes the path with the current line attributes, then the + path is discarded.
- CD_PATH_FILLSTROKE - fills the path with the current fill attributes, strokes the path with the current line attributes, then the path - is discarded
- "CLIP" - closes the path, and use it as a clipping area to be - intersected with the current clipping area, then the path is discarded
- "NULL" - discards the path and ends the process without any output.
- ARC - If there is a current point an additional straight line is drawn - from the current point to the starting point of the arc. The endpoint of the - arc becomes the new current point.
- CD_PATH_CLIP - use the path as a clipping area to be + intersected with the current clipping area, then the path is discarded.
+
So the normal path creation to draw a line will do:
+
```
cdCanvasBegin(canvas, CD_PATH);
+cdCanvasPathSet(canvas, CD_PATH_MOVETO);
+cdCanvasVertex(canvas, x1, y1);
+cdCanvasPathSet(canvas, CD_PATH_LINETO);
+cdCanvasVertex(canvas, x2, y2);
+cdCanvasPathSet(canvas, CD_PATH_STROKE);
+cdCanvasEnd(canvas);
```
+ + -- cgit v1.2.3