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| author | scuri <scuri> | 2008-10-17 06:10:33 +0000 |
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| committer | scuri <scuri> | 2008-10-17 06:10:33 +0000 |
| commit | 7b52cc13af4e85f1ca2deb6b6c77de9c95ea0dcf (patch) | |
| tree | d0857278bde2eff784227c57dcaf930346ceb7ac /html/en/func/wd.html | |
First commit - moving from LuaForge to SourceForge
Diffstat (limited to 'html/en/func/wd.html')
| -rw-r--r-- | html/en/func/wd.html | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/html/en/func/wd.html b/html/en/func/wd.html new file mode 100644 index 0000000..9c83ec5 --- /dev/null +++ b/html/en/func/wd.html @@ -0,0 +1,80 @@ +<!doctype HTML PUBLIC "-//IETF//DTD HTML//EN"> +<html> + <head> + <title>World Coordinates</title> + <meta http-equiv="Content-Language" content="en-us"> + <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> + <link rel="stylesheet" type="text/css" href="../../style.css"> + </head> + <body> + <h2 align="center">World Coordinates</h2> + <p>Allows the use of a World Coordinate System. In this system you can attribute + coordinates to any unit you want. After you define a window (rectangular + region) in your world, each given coordinate is then mapped to canvas + coordinates to draw the primitives. You can define a viewport in your canvas to + change the coordinate mapping from world to canvas. The image below shows the + relation between Window and Viewport.</p> + <p align="center"><font size="4">Window x Viewport</font><br> + <img src="../../img/wc-dc.gif" border="2" width="330" height="182"></p> + <p>If you want to map coordinates from one system to another, use the <font>wdWorld2Canvas</font> + e <font>wdCanvas2World</font> functions. + </p> + <p>The quality of the picture depends on the conversion from World to Canvas, so + if the canvas has a small size the picture quality will be poor. To increase + picture quality create a canvas with a larger size, if possible.</p> + <p>All World Coordinate drawing in all drivers are simulated using other CD + primitives.</p> + <hr> + <pre class="function"><span class="mainFunction">void <a name="wdWindow">wdCanvasWindow</a>(cdCanvas* canvas, double xmin, double xmax, double ymin, double ymax); [in C]</span> + +canvas:wWindow(xmin, xmax, ymin, ymax: number) [in Lua]</pre> + <p>Configures a window in the world coordinate system to be used to convert world + coordinates (with values in real numbers) into canvas coordinates (with values + in integers). The default window is the size in millimeters of the whole + canvas.</p> + <pre class="function"><span class="mainFunction">void <a name="wdGetWindow">wdCanvasGetWindow</a>(cdCanvas* canvas, double *xmin, double *xmax, double *ymin, double *ymax); [in C]</span> + +canvas:wGetWindow() -> (xmin, xmax, ymin, ymax: number) [in Lua]</pre> + <p>Queries the current window in the world coordinate system being used to + convert world coordinates into canvas coordinates (and the other way round). It + is not necessary to provide all return pointers, you can provide only the + desired values.</p> + <pre class="function"><span class="mainFunction">void <a name="wdViewport">wdCanvasViewport</a>(cdCanvas* canvas, int xmin, int xmax, int ymin, int ymax); [in C]</span> + +canvas:wViewport(xmin, xmax, ymin, ymax: number) [in Lua]</pre> + <p>Configures a viewport in the canvas coordinate system to be used to convert + world coordinates (with values in real numbers) into canvas coordinates (with + values in integers). The default viewport is the whole canvas <font>(0,w-1,0,h-1)</font>. + If the canvas size is changed, the viewport will not be automatically updated. + </p> + <pre class="function"><span class="mainFunction">void <a name="wdGetViewport">wdCanvasGetViewport</a>(cdCanvas* canvas, int *xmin, int *xmax, int *ymin, int *ymax); [in C]</span> + +canvas:wGetViewport() -> (xmin, xmax, ymin, ymax: number) [in Lua]</pre> + <p>Queries the current viewport in the world coordinate system being used to + convert world coordinates into canvas coordinates (and the other way round). It + is not necessary to provide all return pointers, you can provide only the + desired values and <font>NULL</font> for the others.</p> + <pre class="function"><span class="mainFunction">void <a name="wdWorld2Canvas">wdCanvasWorld2Canvas</a>(cdCanvas* canvas, double xw, double yw, int *xv, int *yv); [in C]</span> + +canvas:wWorld2Canvas(xw, yw: number) -> (xv, yv: number) [in Lua]</pre> + <p>Converts world coordinates into canvas coordinates. It is not necessary to + provide all return pointers, you can provide only the desired values and <font>NULL</font> + for the others.</p> + <pre class="function"><span class="mainFunction">void <a name="wdCanvas2World">wdCanvasCanvas2World</a>(cdCanvas* canvas, int xv, int yv, double *xw, double *yw); [in C]</span> + +canvas:wCanvas2World(xv, yv: number) -> (xw, yw: number) [in Lua]</pre> + <p>Converts canvas coordinates into world coordinates. It is not necessary to + provide all return pointers, you can provide only the desired values and <font>NULL</font> + for the others.</p> + <h3>Extra</h3> + <pre class="function"><span class="mainFunction">void <a name="wdHardcopy">wdCanvasHardcopy</a>(cdCanvas *canvas, cdContext* ctx, void *data, void(*draw_func)(cdCanvas *canvas_copy)); [in C]</span> + +canvas:wCanvasHardcopy(ctx: number, data: string or userdata, draw_func: function) [in Lua]</pre> + <p>Creates a new canvas, prepares Window and Viewport according to + the provided canvas, maintaining the aspect ratio and making the drawing occupy + the largest possible area of the new canvas, calls the drawing function (which + must use routines in WC) and, finally, removes the new canvas.</p> + <p>It is usually used for "hard copies" of drawings (print equivalent copy). The + most common used contexts are Printer, PS and PDF.</p> + </body> +</html> |