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-rw-r--r--src/pixman/pixman/pixman-edge.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/src/pixman/pixman/pixman-edge.c b/src/pixman/pixman/pixman-edge.c
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+++ b/src/pixman/pixman/pixman-edge.c
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+/*
+ * Copyright © 2004 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_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+
+#include "pixman-private.h"
+#include "pixman-accessor.h"
+
+/*
+ * Step across a small sample grid gap
+ */
+#define RENDER_EDGE_STEP_SMALL(edge) \
+ { \
+ edge->x += edge->stepx_small; \
+ edge->e += edge->dx_small; \
+ if (edge->e > 0) \
+ { \
+ edge->e -= edge->dy; \
+ edge->x += edge->signdx; \
+ } \
+ }
+
+/*
+ * Step across a large sample grid gap
+ */
+#define RENDER_EDGE_STEP_BIG(edge) \
+ { \
+ edge->x += edge->stepx_big; \
+ edge->e += edge->dx_big; \
+ if (edge->e > 0) \
+ { \
+ edge->e -= edge->dy; \
+ edge->x += edge->signdx; \
+ } \
+ }
+
+#ifdef PIXMAN_FB_ACCESSORS
+#define PIXMAN_RASTERIZE_EDGES pixman_rasterize_edges_accessors
+#else
+#define PIXMAN_RASTERIZE_EDGES pixman_rasterize_edges_no_accessors
+#endif
+
+/*
+ * 4 bit alpha
+ */
+
+#define N_BITS 4
+#define RASTERIZE_EDGES rasterize_edges_4
+
+#ifndef WORDS_BIGENDIAN
+#define SHIFT_4(o) ((o) << 2)
+#else
+#define SHIFT_4(o) ((1 - (o)) << 2)
+#endif
+
+#define GET_4(x, o) (((x) >> SHIFT_4 (o)) & 0xf)
+#define PUT_4(x, o, v) \
+ (((x) & ~(0xf << SHIFT_4 (o))) | (((v) & 0xf) << SHIFT_4 (o)))
+
+#define DEFINE_ALPHA(line, x) \
+ uint8_t *__ap = (uint8_t *) line + ((x) >> 1); \
+ int __ao = (x) & 1
+
+#define STEP_ALPHA ((__ap += __ao), (__ao ^= 1))
+
+#define ADD_ALPHA(a) \
+ { \
+ uint8_t __o = READ (image, __ap); \
+ uint8_t __a = (a) + GET_4 (__o, __ao); \
+ WRITE (image, __ap, PUT_4 (__o, __ao, __a | (0 - ((__a) >> 4)))); \
+ }
+
+#include "pixman-edge-imp.h"
+
+#undef ADD_ALPHA
+#undef STEP_ALPHA
+#undef DEFINE_ALPHA
+#undef RASTERIZE_EDGES
+#undef N_BITS
+
+
+/*
+ * 1 bit alpha
+ */
+
+#define N_BITS 1
+#define RASTERIZE_EDGES rasterize_edges_1
+
+#include "pixman-edge-imp.h"
+
+#undef RASTERIZE_EDGES
+#undef N_BITS
+
+/*
+ * 8 bit alpha
+ */
+
+static force_inline uint8_t
+clip255 (int x)
+{
+ if (x > 255)
+ return 255;
+
+ return x;
+}
+
+#define ADD_SATURATE_8(buf, val, length) \
+ do \
+ { \
+ int i__ = (length); \
+ uint8_t *buf__ = (buf); \
+ int val__ = (val); \
+ \
+ while (i__--) \
+ { \
+ WRITE (image, (buf__), clip255 (READ (image, (buf__)) + (val__))); \
+ (buf__)++; \
+ } \
+ } while (0)
+
+/*
+ * We want to detect the case where we add the same value to a long
+ * span of pixels. The triangles on the end are filled in while we
+ * count how many sub-pixel scanlines contribute to the middle section.
+ *
+ * +--------------------------+
+ * fill_height =| \ /
+ * +------------------+
+ * |================|
+ * fill_start fill_end
+ */
+static void
+rasterize_edges_8 (pixman_image_t *image,
+ pixman_edge_t * l,
+ pixman_edge_t * r,
+ pixman_fixed_t t,
+ pixman_fixed_t b)
+{
+ pixman_fixed_t y = t;
+ uint32_t *line;
+ int fill_start = -1, fill_end = -1;
+ int fill_size = 0;
+ uint32_t *buf = (image)->bits.bits;
+ int stride = (image)->bits.rowstride;
+ int width = (image)->bits.width;
+
+ line = buf + pixman_fixed_to_int (y) * stride;
+
+ for (;;)
+ {
+ uint8_t *ap = (uint8_t *) line;
+ pixman_fixed_t lx, rx;
+ int lxi, rxi;
+
+ /* clip X */
+ lx = l->x;
+ if (lx < 0)
+ lx = 0;
+
+ rx = r->x;
+
+ if (pixman_fixed_to_int (rx) >= width)
+ {
+ /* Use the last pixel of the scanline, covered 100%.
+ * We can't use the first pixel following the scanline,
+ * because accessing it could result in a buffer overrun.
+ */
+ rx = pixman_int_to_fixed (width) - 1;
+ }
+
+ /* Skip empty (or backwards) sections */
+ if (rx > lx)
+ {
+ int lxs, rxs;
+
+ /* Find pixel bounds for span. */
+ lxi = pixman_fixed_to_int (lx);
+ rxi = pixman_fixed_to_int (rx);
+
+ /* Sample coverage for edge pixels */
+ lxs = RENDER_SAMPLES_X (lx, 8);
+ rxs = RENDER_SAMPLES_X (rx, 8);
+
+ /* Add coverage across row */
+ if (lxi == rxi)
+ {
+ WRITE (image, ap + lxi,
+ clip255 (READ (image, ap + lxi) + rxs - lxs));
+ }
+ else
+ {
+ WRITE (image, ap + lxi,
+ clip255 (READ (image, ap + lxi) + N_X_FRAC (8) - lxs));
+
+ /* Move forward so that lxi/rxi is the pixel span */
+ lxi++;
+
+ /* Don't bother trying to optimize the fill unless
+ * the span is longer than 4 pixels. */
+ if (rxi - lxi > 4)
+ {
+ if (fill_start < 0)
+ {
+ fill_start = lxi;
+ fill_end = rxi;
+ fill_size++;
+ }
+ else
+ {
+ if (lxi >= fill_end || rxi < fill_start)
+ {
+ /* We're beyond what we saved, just fill it */
+ ADD_SATURATE_8 (ap + fill_start,
+ fill_size * N_X_FRAC (8),
+ fill_end - fill_start);
+ fill_start = lxi;
+ fill_end = rxi;
+ fill_size = 1;
+ }
+ else
+ {
+ /* Update fill_start */
+ if (lxi > fill_start)
+ {
+ ADD_SATURATE_8 (ap + fill_start,
+ fill_size * N_X_FRAC (8),
+ lxi - fill_start);
+ fill_start = lxi;
+ }
+ else if (lxi < fill_start)
+ {
+ ADD_SATURATE_8 (ap + lxi, N_X_FRAC (8),
+ fill_start - lxi);
+ }
+
+ /* Update fill_end */
+ if (rxi < fill_end)
+ {
+ ADD_SATURATE_8 (ap + rxi,
+ fill_size * N_X_FRAC (8),
+ fill_end - rxi);
+ fill_end = rxi;
+ }
+ else if (fill_end < rxi)
+ {
+ ADD_SATURATE_8 (ap + fill_end,
+ N_X_FRAC (8),
+ rxi - fill_end);
+ }
+ fill_size++;
+ }
+ }
+ }
+ else
+ {
+ ADD_SATURATE_8 (ap + lxi, N_X_FRAC (8), rxi - lxi);
+ }
+
+ WRITE (image, ap + rxi, clip255 (READ (image, ap + rxi) + rxs));
+ }
+ }
+
+ if (y == b)
+ {
+ /* We're done, make sure we clean up any remaining fill. */
+ if (fill_start != fill_end)
+ {
+ if (fill_size == N_Y_FRAC (8))
+ {
+ MEMSET_WRAPPED (image, ap + fill_start,
+ 0xff, fill_end - fill_start);
+ }
+ else
+ {
+ ADD_SATURATE_8 (ap + fill_start, fill_size * N_X_FRAC (8),
+ fill_end - fill_start);
+ }
+ }
+ break;
+ }
+
+ if (pixman_fixed_frac (y) != Y_FRAC_LAST (8))
+ {
+ RENDER_EDGE_STEP_SMALL (l);
+ RENDER_EDGE_STEP_SMALL (r);
+ y += STEP_Y_SMALL (8);
+ }
+ else
+ {
+ RENDER_EDGE_STEP_BIG (l);
+ RENDER_EDGE_STEP_BIG (r);
+ y += STEP_Y_BIG (8);
+ if (fill_start != fill_end)
+ {
+ if (fill_size == N_Y_FRAC (8))
+ {
+ MEMSET_WRAPPED (image, ap + fill_start,
+ 0xff, fill_end - fill_start);
+ }
+ else
+ {
+ ADD_SATURATE_8 (ap + fill_start, fill_size * N_X_FRAC (8),
+ fill_end - fill_start);
+ }
+
+ fill_start = fill_end = -1;
+ fill_size = 0;
+ }
+
+ line += stride;
+ }
+ }
+}
+
+#ifndef PIXMAN_FB_ACCESSORS
+static
+#endif
+void
+PIXMAN_RASTERIZE_EDGES (pixman_image_t *image,
+ pixman_edge_t * l,
+ pixman_edge_t * r,
+ pixman_fixed_t t,
+ pixman_fixed_t b)
+{
+ switch (PIXMAN_FORMAT_BPP (image->bits.format))
+ {
+ case 1:
+ rasterize_edges_1 (image, l, r, t, b);
+ break;
+
+ case 4:
+ rasterize_edges_4 (image, l, r, t, b);
+ break;
+
+ case 8:
+ rasterize_edges_8 (image, l, r, t, b);
+ break;
+
+ default:
+ break;
+ }
+}
+
+#ifndef PIXMAN_FB_ACCESSORS
+
+PIXMAN_EXPORT void
+pixman_rasterize_edges (pixman_image_t *image,
+ pixman_edge_t * l,
+ pixman_edge_t * r,
+ pixman_fixed_t t,
+ pixman_fixed_t b)
+{
+ return_if_fail (image->type == BITS);
+ return_if_fail (PIXMAN_FORMAT_TYPE (image->bits.format) == PIXMAN_TYPE_A);
+
+ if (image->bits.read_func || image->bits.write_func)
+ pixman_rasterize_edges_accessors (image, l, r, t, b);
+ else
+ pixman_rasterize_edges_no_accessors (image, l, r, t, b);
+}
+
+#endif
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