kwh@sei.cmu.edu (Kurt Hoyt) (04/29/88)
What is different between drawing pixmaps using these methods: Method 1 -- XReadBitmapFile XCreatePixmap XCopyPlane /* Turn depth 1 pixmap into window depth pixmap */ XSetWindowBackgroundPixmap ... XMapWindow ... XClearWindow /* In event handler for Expose */ ... Method 2 -- /* Use XReadBitmapFile guts to get the char array data. */ image = XCreateImage (display, NULL, 1, XYBitmap, 0, data, width, height, 8, (width + 7) / 8); image->byte_order = LSBFirst; image->bitmap_unit = 8; image->bitmap_bit_order = LSBFirst; ... XMapWindow ... XPutImage (d, w, gc, image, 0, 0, 0, 0, image->width, image->height); /* Above in event handler for Expose */ ... It would seem that drawing pixmaps is to be done using images, since there are image drawing calls in Xlib, but no pixmap drawing calls. However, programs which are identical except for the pixmap drawing mathod give different results. XSetWindowBackgroundPixmap seem pretty reliable for drawing pixmaps, but it will tile the pixmap. XPutImage puts up scrambled images in some cases, but using the same bytes for the data. What's up? Is it me or a bug? If a bug, I have the small programs and bitmaps to send to MIT. -- Kurt Hoyt, Software Engineering Institute -- kwh@sei.cmu.edu "From previous research with rendering systems we have learned that a good dose of gratuitous partial differential equations is needed to meet the paper quota for impressive formulas." SIGGRAPH '87 Proceedings, p. 73