557 lines
17 KiB
C++
557 lines
17 KiB
C++
//
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// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
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//
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// This software is provided 'as-is', without any express or implied
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// warranty. In no event will the authors be held liable for any damages
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// arising from the use of this software.
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// Permission is granted to anyone to use this software for any purpose,
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// including commercial applications, and to alter it and redistribute it
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// freely, subject to the following restrictions:
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// 1. The origin of this software must not be misrepresented; you must not
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// claim that you wrote the original software. If you use this software
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// in a product, an acknowledgment in the product documentation would be
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// appreciated but is not required.
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// 2. Altered source versions must be plainly marked as such, and must not be
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// misrepresented as being the original software.
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// 3. This notice may not be removed or altered from any source distribution.
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//
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#include <math.h>
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#include <stdio.h>
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#include "Recast.h"
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#include "RecastAlloc.h"
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#include "RecastAssert.h"
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/// Check whether two bounding boxes overlap
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///
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/// @param[in] aMin Min axis extents of bounding box A
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/// @param[in] aMax Max axis extents of bounding box A
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/// @param[in] bMin Min axis extents of bounding box B
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/// @param[in] bMax Max axis extents of bounding box B
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/// @returns true if the two bounding boxes overlap. False otherwise.
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static bool overlapBounds(const float* aMin, const float* aMax, const float* bMin, const float* bMax)
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{
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return
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aMin[0] <= bMax[0] && aMax[0] >= bMin[0] &&
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aMin[1] <= bMax[1] && aMax[1] >= bMin[1] &&
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aMin[2] <= bMax[2] && aMax[2] >= bMin[2];
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}
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/// Allocates a new span in the heightfield.
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/// Use a memory pool and free list to minimize actual allocations.
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///
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/// @param[in] hf The heightfield
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/// @returns A pointer to the allocated or re-used span memory.
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static rcSpan* allocSpan(rcHeightfield& hf)
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{
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// If necessary, allocate new page and update the freelist.
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if (hf.freelist == NULL || hf.freelist->next == NULL)
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{
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// Create new page.
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// Allocate memory for the new pool.
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rcSpanPool* spanPool = (rcSpanPool*)rcAlloc(sizeof(rcSpanPool), RC_ALLOC_PERM);
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if (spanPool == NULL)
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{
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return NULL;
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}
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// Add the pool into the list of pools.
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spanPool->next = hf.pools;
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hf.pools = spanPool;
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// Add new spans to the free list.
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rcSpan* freeList = hf.freelist;
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rcSpan* head = &spanPool->items[0];
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rcSpan* it = &spanPool->items[RC_SPANS_PER_POOL];
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do
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{
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--it;
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it->next = freeList;
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freeList = it;
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}
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while (it != head);
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hf.freelist = it;
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}
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// Pop item from the front of the free list.
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rcSpan* newSpan = hf.freelist;
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hf.freelist = hf.freelist->next;
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return newSpan;
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}
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/// Releases the memory used by the span back to the heightfield, so it can be re-used for new spans.
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/// @param[in] hf The heightfield.
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/// @param[in] span A pointer to the span to free
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static void freeSpan(rcHeightfield& hf, rcSpan* span)
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{
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if (span == NULL)
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{
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return;
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}
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// Add the span to the front of the free list.
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span->next = hf.freelist;
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hf.freelist = span;
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}
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/// Adds a span to the heightfield. If the new span overlaps existing spans,
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/// it will merge the new span with the existing ones.
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///
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/// @param[in] hf Heightfield to add spans to
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/// @param[in] x The new span's column cell x index
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/// @param[in] z The new span's column cell z index
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/// @param[in] min The new span's minimum cell index
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/// @param[in] max The new span's maximum cell index
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/// @param[in] areaID The new span's area type ID
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/// @param[in] flagMergeThreshold How close two spans maximum extents need to be to merge area type IDs
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static bool addSpan(rcHeightfield& hf,
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const int x, const int z,
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const unsigned short min, const unsigned short max,
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const unsigned char areaID, const int flagMergeThreshold)
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{
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// Create the new span.
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rcSpan* newSpan = allocSpan(hf);
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if (newSpan == NULL)
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{
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return false;
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}
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newSpan->smin = min;
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newSpan->smax = max;
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newSpan->area = areaID;
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newSpan->next = NULL;
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const int columnIndex = x + z * hf.width;
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rcSpan* previousSpan = NULL;
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rcSpan* currentSpan = hf.spans[columnIndex];
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// Insert the new span, possibly merging it with existing spans.
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while (currentSpan != NULL)
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{
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if (currentSpan->smin > newSpan->smax)
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{
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// Current span is completely after the new span, break.
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break;
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}
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if (currentSpan->smax < newSpan->smin)
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{
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// Current span is completely before the new span. Keep going.
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previousSpan = currentSpan;
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currentSpan = currentSpan->next;
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}
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else
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{
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// The new span overlaps with an existing span. Merge them.
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if (currentSpan->smin < newSpan->smin)
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{
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newSpan->smin = currentSpan->smin;
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}
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if (currentSpan->smax > newSpan->smax)
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{
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newSpan->smax = currentSpan->smax;
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}
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// Merge flags.
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if (rcAbs((int)newSpan->smax - (int)currentSpan->smax) <= flagMergeThreshold)
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{
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// Higher area ID numbers indicate higher resolution priority.
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newSpan->area = rcMax(newSpan->area, currentSpan->area);
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}
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// Remove the current span since it's now merged with newSpan.
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// Keep going because there might be other overlapping spans that also need to be merged.
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rcSpan* next = currentSpan->next;
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freeSpan(hf, currentSpan);
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if (previousSpan)
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{
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previousSpan->next = next;
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}
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else
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{
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hf.spans[columnIndex] = next;
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}
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currentSpan = next;
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}
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}
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// Insert new span after prev
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if (previousSpan != NULL)
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{
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newSpan->next = previousSpan->next;
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previousSpan->next = newSpan;
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}
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else
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{
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// This span should go before the others in the list
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newSpan->next = hf.spans[columnIndex];
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hf.spans[columnIndex] = newSpan;
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}
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return true;
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}
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bool rcAddSpan(rcContext* context, rcHeightfield& heightfield,
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const int x, const int z,
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const unsigned short spanMin, const unsigned short spanMax,
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const unsigned char areaID, const int flagMergeThreshold)
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{
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rcAssert(context);
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if (!addSpan(heightfield, x, z, spanMin, spanMax, areaID, flagMergeThreshold))
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{
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context->log(RC_LOG_ERROR, "rcAddSpan: Out of memory.");
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return false;
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}
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return true;
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}
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enum rcAxis
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{
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RC_AXIS_X = 0,
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RC_AXIS_Y = 1,
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RC_AXIS_Z = 2
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};
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/// Divides a convex polygon of max 12 vertices into two convex polygons
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/// across a separating axis.
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///
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/// @param[in] inVerts The input polygon vertices
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/// @param[in] inVertsCount The number of input polygon vertices
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/// @param[out] outVerts1 Resulting polygon 1's vertices
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/// @param[out] outVerts1Count The number of resulting polygon 1 vertices
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/// @param[out] outVerts2 Resulting polygon 2's vertices
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/// @param[out] outVerts2Count The number of resulting polygon 2 vertices
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/// @param[in] axisOffset THe offset along the specified axis
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/// @param[in] axis The separating axis
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static void dividePoly(const float* inVerts, int inVertsCount,
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float* outVerts1, int* outVerts1Count,
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float* outVerts2, int* outVerts2Count,
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float axisOffset, rcAxis axis)
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{
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rcAssert(inVertsCount <= 12);
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// How far positive or negative away from the separating axis is each vertex.
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float inVertAxisDelta[12];
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for (int inVert = 0; inVert < inVertsCount; ++inVert)
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{
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inVertAxisDelta[inVert] = axisOffset - inVerts[inVert * 3 + axis];
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}
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int poly1Vert = 0;
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int poly2Vert = 0;
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for (int inVertA = 0, inVertB = inVertsCount - 1; inVertA < inVertsCount; inVertB = inVertA, ++inVertA)
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{
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// If the two vertices are on the same side of the separating axis
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bool sameSide = (inVertAxisDelta[inVertA] >= 0) == (inVertAxisDelta[inVertB] >= 0);
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if (!sameSide)
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{
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float s = inVertAxisDelta[inVertB] / (inVertAxisDelta[inVertB] - inVertAxisDelta[inVertA]);
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outVerts1[poly1Vert * 3 + 0] = inVerts[inVertB * 3 + 0] + (inVerts[inVertA * 3 + 0] - inVerts[inVertB * 3 + 0]) * s;
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outVerts1[poly1Vert * 3 + 1] = inVerts[inVertB * 3 + 1] + (inVerts[inVertA * 3 + 1] - inVerts[inVertB * 3 + 1]) * s;
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outVerts1[poly1Vert * 3 + 2] = inVerts[inVertB * 3 + 2] + (inVerts[inVertA * 3 + 2] - inVerts[inVertB * 3 + 2]) * s;
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rcVcopy(&outVerts2[poly2Vert * 3], &outVerts1[poly1Vert * 3]);
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poly1Vert++;
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poly2Vert++;
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// add the inVertA point to the right polygon. Do NOT add points that are on the dividing line
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// since these were already added above
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if (inVertAxisDelta[inVertA] > 0)
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{
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rcVcopy(&outVerts1[poly1Vert * 3], &inVerts[inVertA * 3]);
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poly1Vert++;
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}
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else if (inVertAxisDelta[inVertA] < 0)
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{
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rcVcopy(&outVerts2[poly2Vert * 3], &inVerts[inVertA * 3]);
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poly2Vert++;
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}
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}
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else
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{
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// add the inVertA point to the right polygon. Addition is done even for points on the dividing line
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if (inVertAxisDelta[inVertA] >= 0)
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{
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rcVcopy(&outVerts1[poly1Vert * 3], &inVerts[inVertA * 3]);
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poly1Vert++;
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if (inVertAxisDelta[inVertA] != 0)
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{
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continue;
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}
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}
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rcVcopy(&outVerts2[poly2Vert * 3], &inVerts[inVertA * 3]);
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poly2Vert++;
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}
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}
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*outVerts1Count = poly1Vert;
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*outVerts2Count = poly2Vert;
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}
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/// Rasterize a single triangle to the heightfield.
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///
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/// This code is extremely hot, so much care should be given to maintaining maximum perf here.
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///
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/// @param[in] v0 Triangle vertex 0
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/// @param[in] v1 Triangle vertex 1
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/// @param[in] v2 Triangle vertex 2
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/// @param[in] areaID The area ID to assign to the rasterized spans
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/// @param[in] hf Heightfield to rasterize into
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/// @param[in] hfBBMin The min extents of the heightfield bounding box
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/// @param[in] hfBBMax The max extents of the heightfield bounding box
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/// @param[in] cellSize The x and z axis size of a voxel in the heightfield
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/// @param[in] inverseCellSize 1 / cellSize
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/// @param[in] inverseCellHeight 1 / cellHeight
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/// @param[in] flagMergeThreshold The threshold in which area flags will be merged
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/// @returns true if the operation completes successfully. false if there was an error adding spans to the heightfield.
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static bool rasterizeTri(const float* v0, const float* v1, const float* v2,
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const unsigned char areaID, rcHeightfield& hf,
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const float* hfBBMin, const float* hfBBMax,
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const float cellSize, const float inverseCellSize, const float inverseCellHeight,
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const int flagMergeThreshold)
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{
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// Calculate the bounding box of the triangle.
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float triBBMin[3];
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rcVcopy(triBBMin, v0);
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rcVmin(triBBMin, v1);
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rcVmin(triBBMin, v2);
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float triBBMax[3];
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rcVcopy(triBBMax, v0);
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rcVmax(triBBMax, v1);
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rcVmax(triBBMax, v2);
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// If the triangle does not touch the bounding box of the heightfield, skip the triangle.
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if (!overlapBounds(triBBMin, triBBMax, hfBBMin, hfBBMax))
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{
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return true;
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}
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const int w = hf.width;
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const int h = hf.height;
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const float by = hfBBMax[1] - hfBBMin[1];
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// Calculate the footprint of the triangle on the grid's z-axis
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int z0 = (int)((triBBMin[2] - hfBBMin[2]) * inverseCellSize);
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int z1 = (int)((triBBMax[2] - hfBBMin[2]) * inverseCellSize);
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// use -1 rather than 0 to cut the polygon properly at the start of the tile
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z0 = rcClamp(z0, -1, h - 1);
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z1 = rcClamp(z1, 0, h - 1);
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// Clip the triangle into all grid cells it touches.
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float buf[7 * 3 * 4];
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float* in = buf;
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float* inRow = buf + 7 * 3;
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float* p1 = inRow + 7 * 3;
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float* p2 = p1 + 7 * 3;
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rcVcopy(&in[0], v0);
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rcVcopy(&in[1 * 3], v1);
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rcVcopy(&in[2 * 3], v2);
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int nvRow;
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int nvIn = 3;
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for (int z = z0; z <= z1; ++z)
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{
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// Clip polygon to row. Store the remaining polygon as well
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const float cellZ = hfBBMin[2] + (float)z * cellSize;
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dividePoly(in, nvIn, inRow, &nvRow, p1, &nvIn, cellZ + cellSize, RC_AXIS_Z);
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rcSwap(in, p1);
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if (nvRow < 3)
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{
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continue;
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}
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if (z < 0)
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{
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continue;
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}
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// find X-axis bounds of the row
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float minX = inRow[0];
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float maxX = inRow[0];
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for (int vert = 1; vert < nvRow; ++vert)
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{
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if (minX > inRow[vert * 3])
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{
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minX = inRow[vert * 3];
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}
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if (maxX < inRow[vert * 3])
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{
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maxX = inRow[vert * 3];
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}
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}
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int x0 = (int)((minX - hfBBMin[0]) * inverseCellSize);
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int x1 = (int)((maxX - hfBBMin[0]) * inverseCellSize);
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if (x1 < 0 || x0 >= w)
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{
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continue;
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}
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x0 = rcClamp(x0, -1, w - 1);
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x1 = rcClamp(x1, 0, w - 1);
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int nv;
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int nv2 = nvRow;
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for (int x = x0; x <= x1; ++x)
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{
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// Clip polygon to column. store the remaining polygon as well
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const float cx = hfBBMin[0] + (float)x * cellSize;
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dividePoly(inRow, nv2, p1, &nv, p2, &nv2, cx + cellSize, RC_AXIS_X);
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rcSwap(inRow, p2);
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if (nv < 3)
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{
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continue;
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}
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if (x < 0)
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{
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continue;
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}
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// Calculate min and max of the span.
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float spanMin = p1[1];
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float spanMax = p1[1];
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for (int vert = 1; vert < nv; ++vert)
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{
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spanMin = rcMin(spanMin, p1[vert * 3 + 1]);
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spanMax = rcMax(spanMax, p1[vert * 3 + 1]);
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}
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spanMin -= hfBBMin[1];
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spanMax -= hfBBMin[1];
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// Skip the span if it's completely outside the heightfield bounding box
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if (spanMax < 0.0f)
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{
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continue;
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}
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if (spanMin > by)
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{
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continue;
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}
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// Clamp the span to the heightfield bounding box.
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if (spanMin < 0.0f)
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{
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spanMin = 0;
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}
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if (spanMax > by)
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{
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spanMax = by;
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}
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// Snap the span to the heightfield height grid.
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unsigned short spanMinCellIndex = (unsigned short)rcClamp((int)floorf(spanMin * inverseCellHeight), 0, RC_SPAN_MAX_HEIGHT);
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unsigned short spanMaxCellIndex = (unsigned short)rcClamp((int)ceilf(spanMax * inverseCellHeight), (int)spanMinCellIndex + 1, RC_SPAN_MAX_HEIGHT);
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if (!addSpan(hf, x, z, spanMinCellIndex, spanMaxCellIndex, areaID, flagMergeThreshold))
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{
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return false;
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}
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}
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}
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return true;
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}
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bool rcRasterizeTriangle(rcContext* context,
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const float* v0, const float* v1, const float* v2,
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const unsigned char areaID, rcHeightfield& heightfield, const int flagMergeThreshold)
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{
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rcAssert(context != NULL);
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rcScopedTimer timer(context, RC_TIMER_RASTERIZE_TRIANGLES);
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// Rasterize the single triangle.
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const float inverseCellSize = 1.0f / heightfield.cs;
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const float inverseCellHeight = 1.0f / heightfield.ch;
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if (!rasterizeTri(v0, v1, v2, areaID, heightfield, heightfield.bmin, heightfield.bmax, heightfield.cs, inverseCellSize, inverseCellHeight, flagMergeThreshold))
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{
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context->log(RC_LOG_ERROR, "rcRasterizeTriangle: Out of memory.");
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return false;
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}
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return true;
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}
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bool rcRasterizeTriangles(rcContext* context,
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const float* verts, const int /*nv*/,
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const int* tris, const unsigned char* triAreaIDs, const int numTris,
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rcHeightfield& heightfield, const int flagMergeThreshold)
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{
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rcAssert(context != NULL);
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rcScopedTimer timer(context, RC_TIMER_RASTERIZE_TRIANGLES);
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// Rasterize the triangles.
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const float inverseCellSize = 1.0f / heightfield.cs;
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const float inverseCellHeight = 1.0f / heightfield.ch;
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for (int triIndex = 0; triIndex < numTris; ++triIndex)
|
|
{
|
|
const float* v0 = &verts[tris[triIndex * 3 + 0] * 3];
|
|
const float* v1 = &verts[tris[triIndex * 3 + 1] * 3];
|
|
const float* v2 = &verts[tris[triIndex * 3 + 2] * 3];
|
|
if (!rasterizeTri(v0, v1, v2, triAreaIDs[triIndex], heightfield, heightfield.bmin, heightfield.bmax, heightfield.cs, inverseCellSize, inverseCellHeight, flagMergeThreshold))
|
|
{
|
|
context->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool rcRasterizeTriangles(rcContext* context,
|
|
const float* verts, const int /*nv*/,
|
|
const unsigned short* tris, const unsigned char* triAreaIDs, const int numTris,
|
|
rcHeightfield& heightfield, const int flagMergeThreshold)
|
|
{
|
|
rcAssert(context != NULL);
|
|
|
|
rcScopedTimer timer(context, RC_TIMER_RASTERIZE_TRIANGLES);
|
|
|
|
// Rasterize the triangles.
|
|
const float inverseCellSize = 1.0f / heightfield.cs;
|
|
const float inverseCellHeight = 1.0f / heightfield.ch;
|
|
for (int triIndex = 0; triIndex < numTris; ++triIndex)
|
|
{
|
|
const float* v0 = &verts[tris[triIndex * 3 + 0] * 3];
|
|
const float* v1 = &verts[tris[triIndex * 3 + 1] * 3];
|
|
const float* v2 = &verts[tris[triIndex * 3 + 2] * 3];
|
|
if (!rasterizeTri(v0, v1, v2, triAreaIDs[triIndex], heightfield, heightfield.bmin, heightfield.bmax, heightfield.cs, inverseCellSize, inverseCellHeight, flagMergeThreshold))
|
|
{
|
|
context->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool rcRasterizeTriangles(rcContext* context,
|
|
const float* verts, const unsigned char* triAreaIDs, const int numTris,
|
|
rcHeightfield& heightfield, const int flagMergeThreshold)
|
|
{
|
|
rcAssert(context != NULL);
|
|
|
|
rcScopedTimer timer(context, RC_TIMER_RASTERIZE_TRIANGLES);
|
|
|
|
// Rasterize the triangles.
|
|
const float inverseCellSize = 1.0f / heightfield.cs;
|
|
const float inverseCellHeight = 1.0f / heightfield.ch;
|
|
for (int triIndex = 0; triIndex < numTris; ++triIndex)
|
|
{
|
|
const float* v0 = &verts[(triIndex * 3 + 0) * 3];
|
|
const float* v1 = &verts[(triIndex * 3 + 1) * 3];
|
|
const float* v2 = &verts[(triIndex * 3 + 2) * 3];
|
|
if (!rasterizeTri(v0, v1, v2, triAreaIDs[triIndex], heightfield, heightfield.bmin, heightfield.bmax, heightfield.cs, inverseCellSize, inverseCellHeight, flagMergeThreshold))
|
|
{
|
|
context->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|