xserver-multidpi/fb/fbstipple.c

/*
 * Copyright © 1998 Keith Packard
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Keith Packard not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  Keith Packard makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include "fb.h"

/*
 * This is a slight abuse of the preprocessor to generate repetitive
 * code, the idea is to generate code for each case of a copy-mode
 * transparent stipple
 */
#define LaneCases1(c,a)	    case c: \
				while (n--) { FbLaneCase(c,a); a++; } \
				break
#define LaneCases2(c,a)	    LaneCases1(c,a); LaneCases1(c+1,a)
#define LaneCases4(c,a)	    LaneCases2(c,a); LaneCases2(c+2,a)
#define LaneCases8(c,a)	    LaneCases4(c,a); LaneCases4(c+4,a)
#define LaneCases16(c,a)    LaneCases8(c,a); LaneCases8(c+8,a)
#define LaneCases32(c,a)    LaneCases16(c,a); LaneCases16(c+16,a)
#define LaneCases64(c,a)    LaneCases32(c,a); LaneCases32(c+32,a)
#define LaneCases128(c,a)   LaneCases64(c,a); LaneCases64(c+64,a)
#define LaneCases256(c,a)   LaneCases128(c,a); LaneCases128(c+128,a)

#if FB_SHIFT == 6
#define LaneCases(a)	    LaneCases256(0,a)
#endif

#if FB_SHIFT == 5
#define LaneCases(a)	    LaneCases16(0,a)
#endif

/*
 * Repeat a transparent stipple across a scanline n times
 */

void
fbTransparentSpan(FbBits * dst, FbBits stip, FbBits fgxor, int n)
{
    FbStip s;

    s = ((FbStip) (stip) & 0x01);
    s |= ((FbStip) (stip >> 8) & 0x02);
    s |= ((FbStip) (stip >> 16) & 0x04);
    s |= ((FbStip) (stip >> 24) & 0x08);
#if FB_SHIFT > 5
    s |= ((FbStip) (stip >> 32) & 0x10);
    s |= ((FbStip) (stip >> 40) & 0x20);
    s |= ((FbStip) (stip >> 48) & 0x40);
    s |= ((FbStip) (stip >> 56) & 0x80);
#endif
    switch (s) {
        LaneCases(dst);
    }
}

void
fbEvenStipple(FbBits * dst,
              FbStride dstStride,
              int dstX,
              int dstBpp,
              int width,
              int height,
              FbStip * stip,
              FbStride stipStride,
              int stipHeight,
              FbBits fgand,
              FbBits fgxor, FbBits bgand, FbBits bgxor, int xRot, int yRot)
{
    FbBits startmask, endmask;
    FbBits mask, and, xor;
    int nmiddle, n;
    FbStip *s, *stipEnd, bits;
    int rot, stipX, stipY;
    int pixelsPerDst;
    const FbBits *fbBits;
    Bool transparent;
    int startbyte, endbyte;

    /*
     * Check for a transparent stipple (stencil)
     */
    transparent = FALSE;
    if (dstBpp >= 8 && fgand == 0 && bgand == FB_ALLONES && bgxor == 0)
        transparent = TRUE;

    pixelsPerDst = FB_UNIT / dstBpp;
    /*
     * Adjust dest pointers
     */
    dst += dstX >> FB_SHIFT;
    dstX &= FB_MASK;
    FbMaskBitsBytes(dstX, width, fgand == 0 && bgand == 0,
                    startmask, startbyte, nmiddle, endmask, endbyte);

    if (startmask)
        dstStride--;
    dstStride -= nmiddle;

    xRot *= dstBpp;
    /*
     * Compute stip start scanline and rotation parameters
     */
    stipEnd = stip + stipStride * stipHeight;
    modulus(-yRot, stipHeight, stipY);
    s = stip + stipStride * stipY;
    modulus(-xRot, FB_UNIT, stipX);
    rot = stipX;

    /*
     * Get pointer to stipple mask array for this depth
     */
    /* fbStippleTable covers all valid bpp (4,8,16,32) */
    fbBits = fbStippleTable[pixelsPerDst];

    while (height--) {
        /*
         * Extract stipple bits for this scanline;
         */
        bits = READ(s);
        s += stipStride;
        if (s == stipEnd)
            s = stip;
#if FB_UNIT > 32
        if (pixelsPerDst == 16)
            mask = FbStipple16Bits(FbLeftStipBits(bits, 16));
        else
#endif
            mask = fbBits[FbLeftStipBits(bits, pixelsPerDst)];
        /*
         * Rotate into position and compute reduced rop values
         */
        mask = FbRotLeft(mask, rot);
        and = (fgand & mask) | (bgand & ~mask);
        xor = (fgxor & mask) | (bgxor & ~mask);

        if (transparent) {
            if (startmask) {
                fbTransparentSpan(dst, mask & startmask, fgxor, 1);
                dst++;
            }
            fbTransparentSpan(dst, mask, fgxor, nmiddle);
            dst += nmiddle;
            if (endmask)
                fbTransparentSpan(dst, mask & endmask, fgxor, 1);
        }
        else {
            /*
             * Fill scanline
             */
            if (startmask) {
                FbDoLeftMaskByteRRop(dst, startbyte, startmask, and, xor);
                dst++;
            }
            n = nmiddle;
            if (!and)
                while (n--)
                    WRITE(dst++, xor);
            else {
                while (n--) {
                    WRITE(dst, FbDoRRop(READ(dst), and, xor));
                    dst++;
                }
            }
            if (endmask)
                FbDoRightMaskByteRRop(dst, endbyte, endmask, and, xor);
        }
        dst += dstStride;
    }
}

void
fbOddStipple(FbBits * dst,
             FbStride dstStride,
             int dstX,
             int dstBpp,
             int width,
             int height,
             FbStip * stip,
             FbStride stipStride,
             int stipWidth,
             int stipHeight,
             FbBits fgand,
             FbBits fgxor, FbBits bgand, FbBits bgxor, int xRot, int yRot)
{
    int stipX, stipY, sx;
    int widthTmp;
    int h, w;
    int x, y;

    modulus(-yRot, stipHeight, stipY);
    modulus(dstX / dstBpp - xRot, stipWidth, stipX);
    y = 0;
    while (height) {
        h = stipHeight - stipY;
        if (h > height)
            h = height;
        height -= h;
        widthTmp = width;
        x = dstX;
        sx = stipX;
        while (widthTmp) {
            w = (stipWidth - sx) * dstBpp;
            if (w > widthTmp)
                w = widthTmp;
            widthTmp -= w;
            fbBltOne(stip + stipY * stipStride,
                     stipStride,
                     sx,
                     dst + y * dstStride,
                     dstStride, x, dstBpp, w, h, fgand, fgxor, bgand, bgxor);
            x += w;
            sx = 0;
        }
        y += h;
        stipY = 0;
    }
}

void
fbStipple(FbBits * dst,
          FbStride dstStride,
          int dstX,
          int dstBpp,
          int width,
          int height,
          FbStip * stip,
          FbStride stipStride,
          int stipWidth,
          int stipHeight,
          Bool even,
          FbBits fgand,
          FbBits fgxor, FbBits bgand, FbBits bgxor, int xRot, int yRot)
{
    if (even)
        fbEvenStipple(dst, dstStride, dstX, dstBpp, width, height,
                      stip, stipStride, stipHeight,
                      fgand, fgxor, bgand, bgxor, xRot, yRot);
    else
        fbOddStipple(dst, dstStride, dstX, dstBpp, width, height,
                     stip, stipStride, stipWidth, stipHeight,
                     fgand, fgxor, bgand, bgxor, xRot, yRot);
}