/* * Copyright (c) 1999, 2000 Greg Haerr <greg@censoft.com> * * 4bpp Packed Linear Video Driver (reversed nibble order) * For Psion S5 * * If INVERT4BPP is defined, then the values are inverted before drawing. * * 	In this driver, psd->linelen is line byte length, not line pixel length *//*#define NDEBUG*/#include <assert.h>#include <string.h>#include "device.h"#include "fb.h"#if INVERT4BPP#define INVERT(c)	((c) = (~c & 0x0f))#else#define INVERT(c)#endifstatic unsigned char notmask[2] = { 0xf0, 0x0f};/* Calc linelen and mmap size, return 0 on fail*/static intlinear4_init(PSD psd){	if (!psd->size)		psd->size = psd->yres * psd->linelen;	/* linelen in bytes for bpp 1, 2, 4, 8 so no change*/	return 1;}/* Set pixel at x, y, to pixelval c*/static voidlinear4_drawpixel(PSD psd, MWCOORD x, MWCOORD y, MWPIXELVAL c){	ADDR8	addr = psd->addr;	assert (addr != 0);	assert (x >= 0 && x < psd->xres);	assert (y >= 0 && y < psd->yres);	assert (c < psd->ncolors);	INVERT(c);	DRAWON;	addr += (x>>1) + y * psd->linelen;	if(gr_mode == MWMODE_XOR)		*addr ^= c << ((x&1)<<2);	else		*addr = (*addr & notmask[x&1]) | (c << ((x&1)<<2));	DRAWOFF;}/* Read pixel at x, y*/static MWPIXELVALlinear4_readpixel(PSD psd, MWCOORD x, MWCOORD y){	ADDR8		addr = psd->addr;	MWPIXELVAL	c;	assert (addr != 0);	assert (x >= 0 && x < psd->xres);	assert (y >= 0 && y < psd->yres);	c = (addr[(x>>1) + y * psd->linelen] >> ((x&1)<<2) ) & 0x0f;	INVERT(c);	return c;	}/* Draw horizontal line from x1,y to x2,y including final point*/static voidlinear4_drawhorzline(PSD psd, MWCOORD x1, MWCOORD x2, MWCOORD y, MWPIXELVAL c){	ADDR8	addr = psd->addr;	assert (addr != 0);	assert (x1 >= 0 && x1 < psd->xres);	assert (x2 >= 0 && x2 < psd->xres);	assert (x2 >= x1);	assert (y >= 0 && y < psd->yres);	assert (c < psd->ncolors);	INVERT(c);	DRAWON;	addr += (x1>>1) + y * psd->linelen;	if(gr_mode == MWMODE_XOR) {		while(x1 <= x2) {			*addr ^= c << ((x1&1)<<2);			if((++x1 & 1) == 0)				++addr;		}	} else {		while(x1 <= x2) {			*addr = (*addr & notmask[x1&1]) | (c << ((x1&1)<<2));			if((++x1 & 1) == 0)				++addr;		}	}	DRAWOFF;}/* Draw a vertical line from x,y1 to x,y2 including final point*/static voidlinear4_drawvertline(PSD psd, MWCOORD x, MWCOORD y1, MWCOORD y2, MWPIXELVAL c){	ADDR8	addr = psd->addr;	int	linelen = psd->linelen;	assert (addr != 0);	assert (x >= 0 && x < psd->xres);	assert (y1 >= 0 && y1 < psd->yres);	assert (y2 >= 0 && y2 < psd->yres);	assert (y2 >= y1);	assert (c < psd->ncolors);	INVERT(c);	DRAWON;	addr += (x>>1) + y1 * linelen;	if(gr_mode == MWMODE_XOR)		while(y1++ <= y2) {			*addr ^= c << ((x&1)<<2);			addr += linelen;		}	else		while(y1++ <= y2) {			*addr = (*addr & notmask[x&1]) | (c << ((x&1)<<2));			addr += linelen;		}	DRAWOFF;}/* srccopy bitblt, opcode is currently ignored*/static voidlinear4_blit(PSD dstpsd, MWCOORD dstx, MWCOORD dsty, MWCOORD w, MWCOORD h,	PSD srcpsd, MWCOORD srcx, MWCOORD srcy, long op){	ADDR8	dst;	ADDR8	src;	int	i;	int	dlinelen = dstpsd->linelen;	int	slinelen = srcpsd->linelen;	assert (dstpsd->addr != 0);	assert (dstx >= 0 && dstx < dstpsd->xres);	assert (dsty >= 0 && dsty < dstpsd->yres);	assert (w > 0);	assert (h > 0);	assert (srcpsd->addr != 0);	assert (srcx >= 0 && srcx < srcpsd->xres);	assert (srcy >= 0 && srcy < srcpsd->yres);	assert (dstx+w <= dstpsd->xres);	assert (dsty+h <= dstpsd->yres);	assert (srcx+w <= srcpsd->xres);	assert (srcy+h <= srcpsd->yres);	DRAWON;	dst = dstpsd->addr + (dstx>>1) + dsty * dlinelen;	src = srcpsd->addr + (srcx>>1) + srcy * slinelen;	while(--h >= 0) {		ADDR8	d = dst;		ADDR8	s = src;		MWCOORD	dx = dstx;		MWCOORD	sx = srcx;		for(i=0; i<w; ++i) {#if INVERT4BPP			unsigned char c = *s;			INVERT(c);			*d = (*d & notmask[dx&1]) |			   ((c >> ((sx&1)<<2) & 0x0f) << ((dx&1)<<2));#else			*d = (*d & notmask[dx&1]) |			   ((*s >> ((sx&1)<<2) & 0x0f) << ((dx&1)<<2));#endif			if((++dx & 1) == 0)				++d;			if((++sx & 1) == 0)				++s;		}		dst += dlinelen;		src += slinelen;	}	DRAWOFF;}SUBDRIVER fblinear4 = {	linear4_init,	linear4_drawpixel,	linear4_readpixel,	linear4_drawhorzline,	linear4_drawvertline,	gen_fillrect,	linear4_blit};