From 7b52cc13af4e85f1ca2deb6b6c77de9c95ea0dcf Mon Sep 17 00:00:00 2001 From: scuri Date: Fri, 17 Oct 2008 06:10:33 +0000 Subject: First commit - moving from LuaForge to SourceForge --- html/en/func/lines.html | 147 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 html/en/func/lines.html (limited to 'html/en/func/lines.html') diff --git a/html/en/func/lines.html b/html/en/func/lines.html new file mode 100644 index 0000000..33dd7e4 --- /dev/null +++ b/html/en/func/lines.html @@ -0,0 +1,147 @@ + + + + + + +Lines + + + + + +

Lines

+ +

Line are segments that connects 2 or more points. The Line + function includes the 2 given points and draws the line using the foreground + color. Line thickness is controlled by the LineWidth function. + By using function LineStyle you can draw dashed lines with some + variations. Lines with a style other than continuous are affected by the back + opacity attribute and by the background color.

+ +
+
void cdCanvasLine(cdCanvas* canvas, int x1, int y1, int x2, int y2); [in C]
+void cdfCanvasLine(cdCanvas* canvas, double x1, double y1, double x2, double y2); [in C]
void wdCanvasLine(cdCanvas* canvas, double x1, double y1, double x2, double y2); (WC) [in C]
+
+canvas:Line(x1, y1, x2, y2: number) [in Lua]
+canvas:fLine(x1, y1, x2, y2: number) [in Lua]
+canvas:wLine(x1, y1, x2, y2: number) (WC) [in Lua]
+ +

Draws a line from (x1,y1) to (x2,y2) using + the current foreground color and line width and style. Both points are + included in the line.

+ +
Polygons and Bezier Lines
+ +

Open polygons can be created using cdBegin(CD_OPEN_LINES)/cdVertex(x,y)/.../cdEnd().

+

Closed polygons use the same number of vertices but the last point is + automatically connected to the first point. Closed polygons can be created + using cdBegin(CD_CLOSED_LINES)/cdVertex(x,y)/.../cdEnd().

+

Bezier lines can be created using cdBegin(CD_BEZIER)/cdVertex(x,y)/.../cdEnd(). + At least 4 vertices must be defined. The two vertices of the middle are the + control vertices. A sequence of bezier lines can be defined using more 3 + vertices, two control points and an end point, the last point of the previous + bezier will be used as the start point.

+

See the documentation of cdBegin/cdVertex/cdEnd.

+ +
void cdCanvasRect(cdCanvas* canvas, int xmin, int xmax, int ymin, int ymax); [in C]
void cdfCanvasRect(cdCanvas* canvas, double xmin, double xmax, double ymin, double ymax); [in C]
+void wdCanvasRect(cdCanvas* canvas, double xmin, double xmax, double ymin, double ymax); (WC) [in C]
+
+canvas:Rect(xmin, xmax, ymin, ymax: number) [in Lua]
+canvas:fRect(xmin, xmax, ymin, ymax: number) [in Lua]
canvas:wRect(xmin, xmax, ymin, ymax: number) (WC) [in Lua]
+ +

Draws a rectangle with no filling. All points in the limits of interval + x_min<=x<=x_max, y_min<=y<=y_max + will be painted. It is affected by line attributes and the foreground color. + If the active driver does not include this primitive, it will be simulated + using the cdLine primitive.

+ +
void cdCanvasArc(cdCanvas* canvas, int xc, int yc, int w, int h, double angle1, double angle2); [in C]
void cdfCanvasArc(cdCanvas* canvas, double xc, double yc, double w, double h, double angle1, double angle2); [in C]
+void wdCanvasArc(cdCanvas* canvas, double xc, double yc, double w, double h, double angle1, double angle2); (WC) [in C]
+
+canvas:Arc(xc, yc, w, h, angle1, angle2: number) [in Lua]
+canvas:fArc(xc, yc, w, h, angle1, angle2: number) [in Lua]
+canvas:wArc(xc, yc, w, h, angle1, angle2: number) (WC) [in Lua]
+ +

Draws the arc of an ellipse aligned with the axis, using the current + foreground color and line width and style. It is drawn counter-clockwise. The + coordinate (xc,yc) defines the center of the ellipse. + Dimensions w and h define the elliptic axes X + and Y, respectively.

+

Angles angle1 and angle2, in degrees define + the arc's beginning and end, but they are not the angle relative to the + center, except when w==h and the ellipse is reduced to a circle. The arc + starts at the point (xc+(w/2)*cos(angle1),yc+(h/2)*sin(angle1)) + and ends at (xc+(w/2)*cos(angle2),yc+(h/2)*sin(angle2)). A + complete ellipse can be drawn using 0 and 360 as the angles.

+

The angles are specified so if the size of the ellipse (w x h) is changed, + its shape is preserved. So the angles relative to the center are dependent + from the ellipse size. The actual angle can be obtained using rangle = + atan2((h/2)*sin(angle),(w/2)*cos(angle)).

+

The angles are given in degrees. To specify the angle in radians, you can + use the definition CD_RAD2DEG + to multiply the value in radians before passing the angle to CD.

+

Arc Parameters
+  

+ +

Attributes

+
int cdCanvasLineStyle(cdCanvas* canvas, int style); [in C]
+
+canvas:LineStyle(style: number) -> (old_style: number) [in Lua]
+ +

Configures the current line style for: CD_CONTINUOUS, CD_DASHED, + CD_DOTTED, CD_DASH_DOT, CD_DASH_DOT_DOT, or CD_CUSTOM. Returns the + previous value. Default value: CD_CONTINUOUS. Value + CD_QUERY simply returns the current value. When CD_CUSTOM + is used the cdLineStyleDahes function must be called before to + initialize the custom dashes. The spaces are drawn with the background color, + except when back opacity is transparent then the background is left unchanged. + See BackOpacity.

+

Line Styles
+

+ +
void cdCanvasLineStyleDashes(cdCanvas* canvas, const int* dashes, int count); [in C]
+
+canvas:LineStyleDashes(dashes: table, count: number) -> (old_style: number) [in Lua]
+ +

Defines the custom line style dashes. The first value is the lenght of the + first dash, the second value is the leght of the first space, and so on. For + example: "10 2 5 2" means dash size 10, space size 2, dash size 5, space size + 2, and repeats the pattern.

+ +
int cdCanvasLineWidth(cdCanvas* canvas, int width); [in C]
double wdCanvasLineWidth(double width_mm); (WC) [in C]
+
+canvas:LineWidth(width: number) -> (old_width: number) [in Lua]
+canvas:wLineWidth(width_mm: number) -> (old_width_mm: number) (WC) [in Lua]
+ +

Configures the width of the current line (in pixels). Returns the previous + value. Default value: 1. Value CD_QUERY simply returns the + current value. Valid width interval: >= 1.

+

In WC, it configures the current line width in millimeters. 

+ +
int cdCanvasLineJoin(cdCanvas* canvas, int style); [in C]
+
+canvas:LineJoin(style: number) -> (old_style: number) [in Lua]
+ +

Configures the current line style for: CD_MITER, + CD_BEVEL or CD_ROUND. Returns the previous value. + Default value: CD_MITER. Value CD_QUERY simply + returns the current value.

+

Line Joins
+

+ +
int cdCanvasLineCap(cdCanvas* canvas, int style); [in C]
+
+canvas:LineCap(style: number) -> (old_style: number) [in Lua]
+ +

Configures the current line style for: CD_CAPFLAT, + CD_CAPSQUARE or CD_CAPROUND. Returns the previous + value. Default value: CD_CAPFLAT. Value CD_QUERY + simply returns the current value.

+

Line Caps
+

+ + + + + -- cgit v1.2.3