fblin24.c

一个linux下的根文件系统的源码

	/* Pointer to the first source pixel */
	next_src_ptr =
		((unsigned char *) srcpsd->addr) +
		3 * (src_y_start * srcpsd->linelen + src_x_start);

	/* Cache the width of a scanline in dest */
	dest_y_step = dstpsd->linelen;

	/* Pointer to the first dest pixel */
	next_dest_ptr =
		((unsigned char *) dstpsd->addr) +
		3 * (dest_y_start * dest_y_step + dest_x_start);

	/* Convert from pixels to bytes (only for this 24bpp mode) */
	src_x_step_normal *= 3;
	src_x_step_one *= 3;
	src_y_step_normal *= 3;
	src_y_step_one *= 3;

	/*
	 * Note: The MWROP_SRC case below is a simple expansion of the
	 * default case.  It can be removed without significant speed
	 * penalty if you need to reduce code size.
	 *
	 * The MWROP_CLEAR case could be removed.  But it is a large
	 * speed increase for a small quantity of code.
	 */
	switch (op & MWROP_EXTENSION) {
	case MWROP_SRC:
		/* Benchmarking shows that this while loop is faster than the equivalent
		 * for loop: for(y_count=0; y_count<height; y_count++) { ... }
		 */
		y_count = height;
		while (y_count-- > 0) {
			src_ptr = next_src_ptr;
			dest_ptr = next_dest_ptr;

			x_error = x_error_start;

			x_count = width;
			while (x_count-- > 0) {
				*dest_ptr++ = src_ptr[0];
				*dest_ptr++ = src_ptr[1];
				*dest_ptr++ = src_ptr[2];

				src_ptr += src_x_step_normal;
				x_error += x_error_step_normal;

				if (x_error >= 0) {
					src_ptr += src_x_step_one;
					x_error -= x_denominator;
				}
			}

			next_dest_ptr += dest_y_step;

			next_src_ptr += src_y_step_normal;
			y_error += y_error_step_normal;

			if (y_error >= 0) {
				next_src_ptr += src_y_step_one;
				y_error -= y_denominator;
			}
		}
		break;

	case MWROP_CLEAR:
		y_count = height;
		while (y_count-- > 0) {
			dest_ptr = next_dest_ptr;
			x_count = width * 3;
			while (x_count-- > 0) {
				*dest_ptr++ = 0;
			}
			next_dest_ptr += dest_y_step;
		}
		break;

	default:
		y_count = height;
		while (y_count-- > 0) {
			src_ptr = next_src_ptr;
			dest_ptr = next_dest_ptr;

			x_error = x_error_start;

			x_count = width;
			while (x_count-- > 0) {
				applyOp(MWROP_TO_MODE(op), src_ptr[0], dest_ptr, ADDR8);
				dest_ptr++;
				applyOp(MWROP_TO_MODE(op), src_ptr[1], dest_ptr, ADDR8);
				dest_ptr++;
				applyOp(MWROP_TO_MODE(op), src_ptr[2], dest_ptr, ADDR8);
				dest_ptr++;

				src_ptr += src_x_step_normal;
				x_error += x_error_step_normal;

				if (x_error >= 0) {
					src_ptr += src_x_step_one;
					x_error -= x_denominator;
				}
			}

			next_dest_ptr += dest_y_step;

			next_src_ptr += src_y_step_normal;
			y_error += y_error_step_normal;

			if (y_error >= 0) {
				next_src_ptr += src_y_step_one;
				y_error -= y_denominator;
			}
		}
		break;

	}
}

#if MW_FEATURE_PSDOP_BITMAP_BYTES_LSB_FIRST
/* psd->DrawArea operation PSDOP_BITMAP_BYTES_LSB_FIRST which
 * takes a pixmap, each line is byte aligned, and copies it
 * to the screen using fg_color and bg_color to replace a 1
 * and 0 in the pixmap.  This pixmap is ordered the wrong
 * way around; it has the leftmost pixel (on the screen) in
 * LSB (Bit 0) of the bytes.
 *
 * The reason why this non-intuitive bit ordering is used is
 * to match the bit ordering used in the T1lib font rendering
 * library.
 *
 * Variables used in the gc:
 *       dstx, dsty, dsth, dstw   Destination rectangle
 *       srcx, srcy               Source rectangle
 *       src_linelen              Linesize in bytes of source
 *       pixels                   Pixmap data
 *       fg_color                 Color of a '1' bit
 *       bg_color                 Color of a '0' bit
 *       gr_usebg                 If set, bg_color is used.  If zero,
 *                                then '0' bits are transparent.
 */
static void
linear24_drawarea_bitmap_bytes_lsb_first(PSD psd, driver_gc_t * gc)
{
/*
 * The difference between the MSB_FIRST and LSB_FIRST variants of
 * this function is simply the definition of these three #defines.
 *
 * MWI_IS_BIT_BEFORE_OR_EQUAL(A,B) returns true if bit A is before
 *     (i.e. to the left of) bit B.
 * MWI_ADVANCE_BIT(X) advances X on to the next bit to the right,
 *     and stores the result back in X.
 * MWI_BIT_NO(N), where 0<=n<=7, gives the Nth bit, where 0 is the
 *     leftmost bit and 7 is the rightmost bit.  This is a constant
 *     iff N is a constant.
 */
#define MWI_IS_BIT_BEFORE_OR_EQUAL(a,b) ((a) <= (b))
#define MWI_ADVANCE_BIT(target) ((target) <<= 1)
#define MWI_BIT_NO(n) (0x01 << (n))

/*
 * Two convenience defines - these are the same for MSB_FIRST and
 * LSB_FIRST.
 */
#define MWI_FIRST_BIT MWI_BIT_NO(0)
#define MWI_LAST_BIT  MWI_BIT_NO(7)

	unsigned char prefix_first_bit;
	unsigned char postfix_first_bit = MWI_FIRST_BIT;
	unsigned char postfix_last_bit;
	unsigned char bitmap_byte;
	unsigned char mask;
	unsigned long fg, bg;
	unsigned char fg_r, fg_g, fg_b, bg_r, bg_g, bg_b;
	int first_byte, last_byte;
	int size_main;
	int t, y;
	unsigned int advance_src, advance_dst;
	ADDR8 src;
	ADDR8 dst;

	/* The bit in the first byte, which corresponds to the leftmost pixel. */
	prefix_first_bit = MWI_BIT_NO(gc->srcx & 7);

	/* The bit in the last byte, which corresponds to the rightmost pixel. */
	postfix_last_bit = MWI_BIT_NO((gc->srcx + gc->dstw - 1) & 7);

	/* The index into each scanline of the first byte to use. */
	first_byte = gc->srcx >> 3;

	/* The index into each scanline of the last byte to use. */
	last_byte = (gc->srcx + gc->dstw - 1) >> 3;

	src = ((ADDR8) gc->pixels) + gc->src_linelen * gc->srcy + first_byte;
	dst = ((ADDR8) psd->addr) + (psd->linelen * gc->dsty + gc->dstx) * 3;
	fg = gc->fg_color;
	fg_r = PIXEL888RED(fg);
	fg_g = PIXEL888GREEN(fg);
	fg_b = PIXEL888BLUE(fg);
	bg = gc->bg_color;
	bg_r = PIXEL888RED(bg);
	bg_g = PIXEL888GREEN(bg);
	bg_b = PIXEL888BLUE(bg);

	advance_src = gc->src_linelen - last_byte + first_byte - 1;
	advance_dst = (psd->linelen - gc->dstw) * 3;

	if (first_byte != last_byte) {
		/* The total number of bytes to use, less the two special-cased
		 * bytes (first and last).
		 */
		size_main = last_byte - first_byte + 1 - 2;

		if (prefix_first_bit == MWI_FIRST_BIT) {
			/* No need to special case. */
			prefix_first_bit = 0;
			size_main++;
		}
		if (postfix_last_bit == MWI_LAST_BIT) {
			/* No need to special case. */
			postfix_last_bit = 0;
			size_main++;
		}
	} else if ((prefix_first_bit == MWI_FIRST_BIT)
		   && (postfix_last_bit == MWI_LAST_BIT)) {
		/* Exactly one byte wide. */
		prefix_first_bit = 0;
		postfix_last_bit = 0;
		size_main = 1;
	} else {
		/* Very narrow pixmap, fits in single first byte. */
		/* Do everything in 'postfix' loop. */
		postfix_first_bit = prefix_first_bit;
		prefix_first_bit = 0;
		size_main = 0;
	}

	DRAWON;

	if (gc->gr_usebg) {
		for (y = 0; y < gc->dsth; y++) {

			/* Do pixels of partial first byte */
			if (prefix_first_bit) {
				bitmap_byte = *src++;
				for (mask = prefix_first_bit; mask;
				     MWI_ADVANCE_BIT(mask)) {
					if (mask & bitmap_byte) {
						*dst++ = fg_b;
						*dst++ = fg_g;
						*dst++ = fg_r;
					} else {
						*dst++ = bg_b;
						*dst++ = bg_g;
						*dst++ = bg_r;
					}
				}
			}

			/* Do all pixels of main part one byte at a time */
			for (t = size_main; t != 0; t--) {
				bitmap_byte = *src++;

				if (MWI_BIT_NO(0) & bitmap_byte) {
					*dst++ = fg_b;
					*dst++ = fg_g;
					*dst++ = fg_r;
				} else {
					*dst++ = bg_b;
					*dst++ = bg_g;
					*dst++ = bg_r;
				}
				if (MWI_BIT_NO(1) & bitmap_byte) {
					*dst++ = fg_b;
					*dst++ = fg_g;
					*dst++ = fg_r;
				} else {
					*dst++ = bg_b;
					*dst++ = bg_g;
					*dst++ = bg_r;
				}
				if (MWI_BIT_NO(2) & bitmap_byte) {
					*dst++ = fg_b;
					*dst++ = fg_g;
					*dst++ = fg_r;
				} else {
					*dst++ = bg_b;
					*dst++ = bg_g;
					*dst++ = bg_r;
				}
				if (MWI_BIT_NO(3) & bitmap_byte) {
					*dst++ = fg_b;
					*dst++ = fg_g;
					*dst++ = fg_r;
				} else {
					*dst++ = bg_b;
					*dst++ = bg_g;
					*dst++ = bg_r;
				}
				if (MWI_BIT_NO(4) & bitmap_byte) {
					*dst++ = fg_b;
					*dst++ = fg_g;
					*dst++ = fg_r;
				} else {
					*dst++ = bg_b;
					*dst++ = bg_g;
					*dst++ = bg_r;
				}
				if (MWI_BIT_NO(5) & bitmap_byte) {
					*dst++ = fg_b;
					*dst++ = fg_g;
					*dst++ = fg_r;
				} else {
					*dst++ = bg_b;
					*dst++ = bg_g;
					*dst++ = bg_r;
				}
				if (MWI_BIT_NO(6) & bitmap_byte) {
					*dst++ = fg_b;
					*dst++ = fg_g;
					*dst++ = fg_r;
				} else {
					*dst++ = bg_b;
					*dst++ = bg_g;
					*dst++ = bg_r;
				}
				if (MWI_BIT_NO(7) & bitmap_byte) {
					*dst++ = fg_b;
					*dst++ = fg_g;
					*dst++ = fg_r;
				} else {
					*dst++ = bg_b;
					*dst++ = bg_g;
					*dst++ = bg_r;
				}
			}

			/* Do last few bits of line */
			if (postfix_last_bit) {
				bitmap_byte = *src++;
				for (mask = postfix_first_bit;
				     MWI_IS_BIT_BEFORE_OR_EQUAL(mask,
								postfix_last_bit);
				     MWI_ADVANCE_BIT(mask)) {
					if (mask & bitmap_byte) {
						*dst++ = fg_b;
						*dst++ = fg_g;
						*dst++ = fg_r;
					} else {
						*dst++ = bg_b;
						*dst++ = bg_g;
						*dst++ = bg_r;
					}
				}
			}

			src += advance_src;
			dst += advance_dst;
		}
	} else {
		for (y = 0; y < gc->dsth; y++) {

			/* Do pixels of partial first byte */
			if (prefix_first_bit) {
				bitmap_byte = *src++;
				for (mask = prefix_first_bit; mask;
				     MWI_ADVANCE_BIT(mask)) {
					if (mask & bitmap_byte) {
						dst[0] = fg_b;
						dst[1] = fg_g;
						dst[2] = fg_r;
					}
					dst += 3;
				}
			}

			/* Do all pixels of main part one byte at a time */
			for (t = size_main; t != 0; t--) {
				bitmap_byte = *src++;

				if (MWI_BIT_NO(0) & bitmap_byte) {
					dst[0 * 3 + 0] = fg_b;
					dst[0 * 3 + 1] = fg_g;
					dst[0 * 3 + 2] = fg_r;
				}
				if (MWI_BIT_NO(1) & bitmap_byte) {
					dst[1 * 3 + 0] = fg_b;
					dst[1 * 3 + 1] = fg_g;
					dst[1 * 3 + 2] = fg_r;
				}
				if (MWI_BIT_NO(2) & bitmap_byte) {
					dst[2 * 3 + 0] = fg_b;
					dst[2 * 3 + 1] = fg_g;
					dst[2 * 3 + 2] = fg_r;
				}
				if (MWI_BIT_NO(3) & bitmap_byte) {
					dst[3 * 3 + 0] = fg_b;
					dst[3 * 3 + 1] = fg_g;
					dst[3 * 3 + 2] = fg_r;
				}
				if (MWI_BIT_NO(4) & bitmap_byte) {
					dst[4 * 3 + 0] = fg_b;
					dst[4 * 3 + 1] = fg_g;
					dst[4 * 3 + 2] = fg_r;
				}
				if (MWI_BIT_NO(5) & bitmap_byte) {
					dst[5 * 3 + 0] = fg_b;
					dst[5 * 3 + 1] = fg_g;
					dst[5 * 3 + 2] = fg_r;
				}
				if (MWI_BIT_NO(6) & bitmap_byte) {
					dst[6 * 3 + 0] = fg_b;
					dst[6 * 3 + 1] = fg_g;
					dst[6 * 3 + 2] = fg_r;
				}
				if (MWI_BIT_NO(7) & bitmap_byte) {
					dst[7 * 3 + 0] = fg_b;
					dst[7 * 3 + 1] = fg_g;
					dst[7 * 3 + 2] = fg_r;
				}
				dst += 8 * 3;
			}

			/* Do last few bits of line */
			if (postfix_last_bit) {
				bitmap_byte = *src++;
				for (mask = postfix_first_bit;
				     MWI_IS_BIT_BEFORE_OR_EQUAL(mask,
								postfix_last_bit);
				     MWI_ADVANCE_BIT(mask)) {
					if (mask & bitmap_byte) {
						dst[0] = fg_b;
						dst[1] = fg_g;
						dst[2] = fg_r;
					}
					dst += 3;
				}
			}

			src += advance_src;
			dst += advance_dst;
		}
	}

	DRAWOFF;

#undef MWI_IS_BIT_BEFORE_OR_EQUAL