b9a21c3c91c47e090316e28d759194e46628ed49vboxsync/*
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * Copyright © 2004 Keith Packard
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync *
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * Permission to use, copy, modify, distribute, and sell this software and its
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * documentation for any purpose is hereby granted without fee, provided that
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * the above copyright notice appear in all copies and that both that
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * copyright notice and this permission notice appear in supporting
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * documentation, and that the name of Keith Packard not be used in
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * advertising or publicity pertaining to distribution of the software without
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * specific, written prior permission. Keith Packard makes no
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * representations about the suitability of this software for any purpose. It
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * is provided "as is" without express or implied warranty.
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync *
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * PERFORMANCE OF THIS SOFTWARE.
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync */
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#ifndef _RENDEREDGE_H_
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define _RENDEREDGE_H_
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#include "picturestr.h"
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define MAX_ALPHA(n) ((1 << (n)) - 1)
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define N_Y_FRAC(n) ((n) == 1 ? 1 : (1 << ((n)/2)) - 1)
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define N_X_FRAC(n) ((1 << ((n)/2)) + 1)
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define STEP_Y_SMALL(n) (xFixed1 / N_Y_FRAC(n))
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define STEP_Y_BIG(n) (xFixed1 - (N_Y_FRAC(n) - 1) * STEP_Y_SMALL(n))
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define Y_FRAC_FIRST(n) (STEP_Y_SMALL(n) / 2)
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define Y_FRAC_LAST(n) (Y_FRAC_FIRST(n) + (N_Y_FRAC(n) - 1) * STEP_Y_SMALL(n))
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define STEP_X_SMALL(n) (xFixed1 / N_X_FRAC(n))
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define STEP_X_BIG(n) (xFixed1 - (N_X_FRAC(n) - 1) * STEP_X_SMALL(n))
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define X_FRAC_FIRST(n) (STEP_X_SMALL(n) / 2)
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define X_FRAC_LAST(n) (X_FRAC_FIRST(n) + (N_X_FRAC(n) - 1) * STEP_X_SMALL(n))
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define RenderSamplesX(x,n) ((n) == 1 ? 0 : (xFixedFrac (x) + X_FRAC_FIRST(n)) / STEP_X_SMALL(n))
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync/*
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * An edge structure. This represents a single polygon edge
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * and can be quickly stepped across small or large gaps in the
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * sample grid
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync */
b9a21c3c91c47e090316e28d759194e46628ed49vboxsynctypedef pixman_edge_t RenderEdge;
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync/*
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * Step across a small sample grid gap
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync */
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define RenderEdgeStepSmall(edge) { \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync edge->x += edge->stepx_small; \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync edge->e += edge->dx_small; \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync if (edge->e > 0) \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync { \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync edge->e -= edge->dy; \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync edge->x += edge->signdx; \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync } \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync}
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync/*
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync * Step across a large sample grid gap
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync */
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#define RenderEdgeStepBig(edge) { \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync edge->x += edge->stepx_big; \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync edge->e += edge->dx_big; \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync if (edge->e > 0) \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync { \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync edge->e -= edge->dy; \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync edge->x += edge->signdx; \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync } \
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync}
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncextern _X_EXPORT xFixed
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncRenderSampleCeilY (xFixed y, int bpp);
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncextern _X_EXPORT xFixed
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncRenderSampleFloorY (xFixed y, int bpp);
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncextern _X_EXPORT void
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncRenderEdgeStep (RenderEdge *e, int n);
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncextern _X_EXPORT void
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncRenderEdgeInit (RenderEdge *e,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync int bpp,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync xFixed y_start,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync xFixed x_top,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync xFixed y_top,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync xFixed x_bot,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync xFixed y_bot);
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncextern _X_EXPORT void
b9a21c3c91c47e090316e28d759194e46628ed49vboxsyncRenderLineFixedEdgeInit (RenderEdge *e,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync int bpp,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync xFixed y,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync xLineFixed *line,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync int x_off,
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync int y_off);
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync
b9a21c3c91c47e090316e28d759194e46628ed49vboxsync#endif /* _RENDEREDGE_H_ */