DLI Implementation and Reference Guide - Datalogics

12.14 DLI Implementation and Reference Guide
"C" Example: Filling An Area With A Pattern
DLPDFPATTERN
*Pattern;
DLPDFCONTENT
*PatContent, *PageCont;
PDGraphicState Concepts and State; Facilities: Guide to the DL Pager Composition System
ASFixedMatrix Matrix;
ASFixedRect BBox;
/* Initialize the graphics state */
State.strokeColorSpec.space = State.fillColorSpec.space =
PDEColorSpaceCreateFromName(ASAtomFromString("DeviceGray"));
State.strokeColorSpec.value.color[0] =
State.strokeColorSpec.value.color[0] = 0;
State->GState.miterLimit = fixedTen;
State->GState.flatness = fixedOne;
State->GState.lineWidth = fixedTwo;
/* Draw the pattern “tile” */
PatContent = dlpdfcontentcreate (Doc);
dlpdfcontentline (PatContent, &State, kPDEStroke,
0, 0, fixedTen + fixedTwo, fixedTen + fixedTwo);
BBox.left = BBox.bottom = 0;
BBox.right = BBox.top = fixedTen + fixedTwo;
Matrix.a = Matrix.d = fixedTwo / 3;
Matrix.b = Matrix.c = Matrix.h = Matrix.v = 0;
Pattern = dlpdfpatterncreate (Doc, PatContent, &BBox, &Matrix,
FALSE, 1, BBox.right - fixedTwo, BBox.top - fixedTwo);
/* Set this pattern as the fill pattern */
dlpdfcontentusefillpattern (PageCont, Pattern);
/* Draw and fill the structure */
...
/* Cancel the fill pattern */
dlpdfcontentusefillpattern (PageCont, NULL);
NOTE: A fill pattern is never destroyed. It becomes a part of the document, and
the space used to define the pattern will be freed automatically when the
document is freed.
Repeating Pattern References
Most often, you will want to create a repertoire of fill patterns that matches the
capabilities of your existing composition engine or of the display devices you have