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DrawFile is a module that renders Draw files.
The following are some small differences between the output of the DrawFile module and !Draw.
A text line that uses a font which can't be found will be rendered (in system font) at a size to fit its bounding box.
Transformed text lines in system font are supported. A transformed text line that uses a font which can't be found will be rendered (in system font) at a size to fit its bounding box. The transformation will be ignored.
In a text area, if you change (for example) the margin size (\M command), the change doesn't take effect until the next output line. In Draw, this refers to printable characters: but in DrawFile, it includes colour and font change commands as well (this is because DrawFile uses the Font Manager to remember the current font and colours). This means that line breaks can happen at slightly different places when using DrawFile.
The following commands cause output to occur:
B C U V <digits>
The following do not:
! ; A D F L M P
By preceding the former with the latter, the problem can be avoided.
For a sprite without a palette, the colours used are the WIMP colours, found by using Wimp_ReadPalette.
| R0 | = | flags:
bit 0 set means render bounding boxes (as dotted red rectangles) bit 1 set means do not render the objects themselves bit 2 set means R5 is used as the flatness parameter |
| R1 | = | pointer to Draw file data |
| R2 | = | size of Draw file in bytes |
| R3 | = | pointer to transformation matrix
0 ![[NOT EQUAL]](../../symbols/entities/8800.png) use identity
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| R4 | = | pointer to clipping rectangle in OS units
0 no clipping rectangle set up
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| R5 | = | flatness with which to render lines (if bit 2 of R0 set) |
All registers preserved
This SWI renders a Draw file at a given screen position where that position is defined as screen position 0, 0 with the x- and y-translations as specified in the transformation matrix. Hence to render a non-rotated 1:1 Draw file at x, y (screen coordinates in OS units) the transformation matrix is:
The effects of calling the module with the matrix not of the form:
(which is a translation and a magnification). If R3 = 0, then unit transformation matrix is assumed (i.e. the Draw file is rendered with its bottom left corner at screen coordinates (0, 0)).
The clipping rectangle is typically a redraw rectangle returned by the Wimp on a redraw window request. If R4 = 0, then the whole Draw file is rendered. If non-zero, only objects which intersect the clipping rectangle are rendered.
extern _kernel_oserror *drawfile_render (int flags,
void *data,
int size,
Transform *trfm,
BBox *clip,
int flatness);
| R0 | = | flags (must be 0) |
| R1 | = | pointer to Draw file data |
| R2 | = | size of Draw file in bytes |
| R3 | = | pointer to transformation matrix
0 use identity
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| R4 | = | pointer to 4-word buffer to hold the bounding box of the Draw file
(x0, y0, x1, y1) in Draw units |
All registers preserved
Buffer pointed at by R4 holds the bounding box of the Draw file (x0, y0, x1, y1) in Draw units
This SWI is used to determine the bounding box (in Draw units) of the given Draw file, as if it were plotted with the transformation given.
extern _kernel_oserror *drawfile_bbox (int flags,
void *data,
int size,
Transform *trfm,
BBox *box);
| R0 | = | flags
bit 0 set means do not download font (passed to PDriver_DeclareFont) |
| R1 | = | pointer to Draw file data |
| R2 | = | size of Draw file in bytes |
All registers preserved
All fonts used by the document have been declared
If a printer requires font declarations, this SWI must be called for each Draw file to be printed, between the calls to PDriver_SelectJob and PDriver_DrawPage.
All fonts are declared as 'kerned', since this includes the non-kerned case.
extern _kernel_oserror *drawfile_declare_fonts (int flags,
void *data,
int size);