72f4ddf532
Since using addresses that might change is something that finally the FSF acknowledge as a plausible scenario (after changing address twice), the license blurb in the source files should use the URI for getting the license in case the library did not come with it. Not that URIs cannot possibly change, but at least it's easier to set up a redirection at the same place. As a side note: this commit closes the oldes bug in Clutter's bug report tool. http://bugzilla.openedhand.com/show_bug.cgi?id=521
132 lines
3.5 KiB
C
132 lines
3.5 KiB
C
/*
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* Cogl
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*
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* An object oriented GL/GLES Abstraction/Utility Layer
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*
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* Copyright (C) 2007,2008,2009 Intel Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library. If not, see <http://www.gnu.org/licenses/>.
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*
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*
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "math.h"
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#include "cogl.h"
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#include "cogl-internal.h"
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#include "cogl-spans.h"
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void
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_cogl_span_iter_update (CoglSpanIter *iter)
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{
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/* Pick current span */
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iter->span = &g_array_index (iter->array, CoglSpan, iter->index);
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/* Offset next position by span size */
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iter->next_pos = iter->pos +
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(float)(iter->span->size - iter->span->waste);
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/* Check if span intersects the area to cover */
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if (iter->next_pos <= iter->cover_start ||
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iter->pos >= iter->cover_end)
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{
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/* Intersection undefined */
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iter->intersects = FALSE;
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return;
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}
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iter->intersects = TRUE;
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/* Clip start position to coverage area */
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if (iter->pos < iter->cover_start)
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iter->intersect_start = iter->cover_start;
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else
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iter->intersect_start = iter->pos;
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/* Clip end position to coverage area */
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if (iter->next_pos > iter->cover_end)
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iter->intersect_end = iter->cover_end;
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else
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iter->intersect_end = iter->next_pos;
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}
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void
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_cogl_span_iter_begin (CoglSpanIter *iter,
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GArray *spans,
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float normalize_factor,
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float cover_start,
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float cover_end)
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{
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float cover_start_normalized;
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iter->index = 0;
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iter->span = NULL;
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iter->array = spans;
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/* We always iterate in a positive direction from the origin. If
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* iter->flipped == TRUE that means whoever is using this API should
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* interpreted the current span as extending in the opposite direction. I.e.
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* it extends to the left if iterating the X axis, or up if the Y axis. */
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if (cover_start > cover_end)
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{
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float tmp = cover_start;
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cover_start = cover_end;
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cover_end = tmp;
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iter->flipped = TRUE;
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}
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else
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iter->flipped = FALSE;
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/* The texture spans cover the normalized texture coordinate space ranging
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* from [0,1] but to help support repeating of sliced textures we allow
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* iteration of any range so we need to relate the start of the range to the
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* nearest point equivalent to 0.
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*/
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cover_start_normalized = cover_start / normalize_factor;
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iter->origin = floorf (cover_start_normalized) * normalize_factor;
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iter->cover_start = cover_start;
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iter->cover_end = cover_end;
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iter->pos = iter->origin;
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/* Update intersection */
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_cogl_span_iter_update (iter);
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}
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void
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_cogl_span_iter_next (CoglSpanIter *iter)
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{
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/* Move current position */
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iter->pos = iter->next_pos;
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/* Pick next slice (wrap when last reached) */
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iter->index = (iter->index + 1) % iter->array->len;
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/* Update intersection */
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_cogl_span_iter_update (iter);
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}
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gboolean
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_cogl_span_iter_end (CoglSpanIter *iter)
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{
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/* End reached when whole area covered */
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return iter->pos >= iter->cover_end;
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}
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