OSSL TextureDrawing

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General Capabilities

The OSSL Texture Drawing functions allow the scripter to dynamically generate a texture on the fly, from within the context of an script. (It can be written in LSL, C# or any other supported scripting language.)

The scripting language supports text and images, as well as three simple drawing primitives: line, rectangle and ellipse. Color and pen attributes are included. Font, size and style are supported for text. An image is specified as an URL.

A drawing script can be directly specified in the texture drawing language, or can be built by using helper functions in the scripting language. Examples of both approaches are shown below.

Several extra parameters are available for the texture rendering operation. These include the height and width of the texture, as well as the background color and alpha value. A statement terminator can also be specified.

LSL Helper Functions

string osMovePen(string drawList, int x, int y);
string osDrawLine(string drawList, int startX, int startY, int endX, int endY);
string osDrawLine(string drawList, int endX, int endY);
string osDrawText(string drawList, string text);
string osDrawEllipse(string drawList, int width, int height);
string osDrawRectangle(string drawList, int width, int height);
string osDrawFilledRectangle(string drawList, int width, int height);
string osDrawPolygon(string drawList, LSL_List x, LSL_List y);
string osSetFontSize(string drawList, int fontSize);
string osSetPenSize(string drawList, int penSize);
string osSetPenColor(string drawList, string colour);
string osSetPenCap(string drawList, string direction, string type);
string osDrawImage(string drawList, int width, int height, string imageUrl);

C# Code Example

public void default_event_state_entry()
    string drawList = "";
    drawList = osDrawLine (drawList, 10,20,240,20);
    drawList = osMovePen (drawList, 50,100); 
    drawList = osDrawImage(drawList, 100,100,"http://opensimulator.org/images/d/de/Opensim_Wright_Plaza.jpg" );
    drawList = osSetPenSize (drawList, 1); 
    drawList = osSetPenCap(drawList, "end", "arrow");
    drawList = osMovePen (drawList, 50,70);
    drawList = osDrawEllipse (drawList, 20,20);
    drawList = osMovePen(drawList, 90,70); 
    drawList = osDrawRectangle (drawList, 20,20 );
    drawList = osMovePen (drawList,130,70); 
    drawList = osDrawFilledRectangle(drawList, 20,20);
    drawList = osDrawPolygon(drawList, [50,100,150], [50,100,50]); 
    drawList = osDrawFilledPolygon(drawList, ["50","100","150"], ["50","100","50"]); // It works with integers, float or string as the x and y points
    drawList = osSetFontSize (drawList, 12 );
    drawList = osMovePen (drawList,15,32); 
    string regionName = llGetRegionName();
    drawList = osDrawText (drawList, "Hello and welcome to " + regionName );
    drawList = osSetFontSize (drawList, 7); 
    drawList = osSetPenColor (drawList, "blue");
    drawList = osMovePen (drawList, 70,220);
    drawList = osDrawText (drawList, "The End");
    osSetDynamicTextureData("", "vector", drawList, "", 0);

OS Dynamic Texture Language

Many of the OSSL drawing functions are convenience functions to help build the command line for the osSetDynamicTextureData data parameter. You may find it easier to build the string yourself using the drawing commands directly. Do this by declaring a string then appending sets of commands and parameters until it is ready. Each command is separated by a semi-colon ";". Additional parameters may be set for the image with the extraParams parameter.

osSetDynamicTextureData(string dynamicID, string contentType, string data, string extraParams, int timer)
  • dynamicID: not used yet – send “”
  • contentType: use “vector” for drawing commands or use “image” for loadurl
  • data: the graphics commands in the string with the format of: “MoveTo 20, 20; FillRectangle 60, 60;”;
  • extraParams: width, height, alpha, bgcolour, altdatadelim
  • timer: set an update interval

Commands (data)

MoveTo int x, int y;
Places the brush at the x/y coordinate
LineTo int x,int y;
Draws line from present pen position to the x/y coordinate
Text string content;
Text to write to the image
Image float x, float y, string URL
The x/y placement coordinates and URL of an image to load
Rectangle float x, float y;
Draws a rectangle with the current pen from the current pen location to the x/y coordinates
FillRectangle float x, float y;
Draws a filled rectangle with the current brush from the current pen location to the x/y coordinates
Ellipse float x, float y;
Draws an ellipse with the current brush from the current brush location to the x/y coordinates
FontSize int size;
The size of the font for text
FontProp char;
  • B Bold
  • I Italic
  • U Underline
  • S Strikeout
  • R Regular
FontName string name;
The name of the font to use
PenSize float size;
Size of the drawing pen
PenColour string color; or PenColor string color;
Drawing color of the pen
PenCap string direction, string type;
Cap of a line, consists of 3 possible directions ("start","end","both") and 4 possible types ("flat","diamond","arrow","round")


string drawData;
drawData += "PenColour Teal; FillRectangle 1024, 512;";
drawData += "PenColour PowderBlue;";
drawData += "MoveTo 40, 30; FontSize 25; Text 2000 UTC:;";
drawData += "MoveTo 250, 30; Text Speed Build Competition;";
drawData += "MoveTo 40, 70; Text 0120 UTC:;";
drawData += "MoveTo 250, 70;Text Working On Sign;";
drawData += "MoveTo 40, 110; Text 0500 UTC:;";
drawData += "MoveTo 250, 110; Text Going To Sleep!;";
drawData += "MoveTo 40, 150; Text 0600 UTC:;";
drawData += "MoveTo 250, 150; FontProp B,I;Text Waking Up!;";
drawData += "FontProp R;";
drawData += "MoveTo 40, 190; Text Have a great day!!;";
drawData += "PenCap end,arrow; LineTo 50,250; MoveTo 50,250;";
osSetDynamicTextureData("","vector", drawData,"width:1024,height:512,alpha:254", 0);

Extra Parameters (extraParams)

the height for the image in pixels
the width of the image in pixels
the opacity of the image
0-255 to set the opacity for an image with an alpha channel
false for an image with no alpha channel
the background color of the image

Microsoft .net colors

an alternative delimiter for each parameter - useful if you want to display text that contains semicolons, for example C# or LSL code.
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