Urho3D/Source/ThirdParty/Recast/Source/RecastRasterization.cpp
2018-09-20 22:17:20 +08:00

455 lines
12 KiB
C++

//
// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//
#define _USE_MATH_DEFINES
#include <math.h>
#include <stdio.h>
#include "Recast.h"
#include "RecastAlloc.h"
#include "RecastAssert.h"
inline bool overlapBounds(const float* amin, const float* amax, const float* bmin, const float* bmax)
{
bool overlap = true;
overlap = (amin[0] > bmax[0] || amax[0] < bmin[0]) ? false : overlap;
overlap = (amin[1] > bmax[1] || amax[1] < bmin[1]) ? false : overlap;
overlap = (amin[2] > bmax[2] || amax[2] < bmin[2]) ? false : overlap;
return overlap;
}
inline bool overlapInterval(unsigned short amin, unsigned short amax,
unsigned short bmin, unsigned short bmax)
{
if (amax < bmin) return false;
if (amin > bmax) return false;
return true;
}
static rcSpan* allocSpan(rcHeightfield& hf)
{
// If running out of memory, allocate new page and update the freelist.
if (!hf.freelist || !hf.freelist->next)
{
// Create new page.
// Allocate memory for the new pool.
rcSpanPool* pool = (rcSpanPool*)rcAlloc(sizeof(rcSpanPool), RC_ALLOC_PERM);
if (!pool) return 0;
// Add the pool into the list of pools.
pool->next = hf.pools;
hf.pools = pool;
// Add new items to the free list.
rcSpan* freelist = hf.freelist;
rcSpan* head = &pool->items[0];
rcSpan* it = &pool->items[RC_SPANS_PER_POOL];
do
{
--it;
it->next = freelist;
freelist = it;
}
while (it != head);
hf.freelist = it;
}
// Pop item from in front of the free list.
rcSpan* it = hf.freelist;
hf.freelist = hf.freelist->next;
return it;
}
static void freeSpan(rcHeightfield& hf, rcSpan* ptr)
{
if (!ptr) return;
// Add the node in front of the free list.
ptr->next = hf.freelist;
hf.freelist = ptr;
}
static bool addSpan(rcHeightfield& hf, const int x, const int y,
const unsigned short smin, const unsigned short smax,
const unsigned char area, const int flagMergeThr)
{
int idx = x + y*hf.width;
rcSpan* s = allocSpan(hf);
if (!s)
return false;
s->smin = smin;
s->smax = smax;
s->area = area;
s->next = 0;
// Empty cell, add the first span.
if (!hf.spans[idx])
{
hf.spans[idx] = s;
return true;
}
rcSpan* prev = 0;
rcSpan* cur = hf.spans[idx];
// Insert and merge spans.
while (cur)
{
if (cur->smin > s->smax)
{
// Current span is further than the new span, break.
break;
}
else if (cur->smax < s->smin)
{
// Current span is before the new span advance.
prev = cur;
cur = cur->next;
}
else
{
// Merge spans.
if (cur->smin < s->smin)
s->smin = cur->smin;
if (cur->smax > s->smax)
s->smax = cur->smax;
// Merge flags.
if (rcAbs((int)s->smax - (int)cur->smax) <= flagMergeThr)
s->area = rcMax(s->area, cur->area);
// Remove current span.
rcSpan* next = cur->next;
freeSpan(hf, cur);
if (prev)
prev->next = next;
else
hf.spans[idx] = next;
cur = next;
}
}
// Insert new span.
if (prev)
{
s->next = prev->next;
prev->next = s;
}
else
{
s->next = hf.spans[idx];
hf.spans[idx] = s;
}
return true;
}
/// @par
///
/// The span addition can be set to favor flags. If the span is merged to
/// another span and the new @p smax is within @p flagMergeThr units
/// from the existing span, the span flags are merged.
///
/// @see rcHeightfield, rcSpan.
bool rcAddSpan(rcContext* ctx, rcHeightfield& hf, const int x, const int y,
const unsigned short smin, const unsigned short smax,
const unsigned char area, const int flagMergeThr)
{
rcAssert(ctx);
if (!addSpan(hf, x, y, smin, smax, area, flagMergeThr))
{
ctx->log(RC_LOG_ERROR, "rcAddSpan: Out of memory.");
return false;
}
return true;
}
// divides a convex polygons into two convex polygons on both sides of a line
static void dividePoly(const float* in, int nin,
float* out1, int* nout1,
float* out2, int* nout2,
float x, int axis)
{
float d[12];
for (int i = 0; i < nin; ++i)
d[i] = x - in[i*3+axis];
int m = 0, n = 0;
for (int i = 0, j = nin-1; i < nin; j=i, ++i)
{
bool ina = d[j] >= 0;
bool inb = d[i] >= 0;
if (ina != inb)
{
float s = d[j] / (d[j] - d[i]);
out1[m*3+0] = in[j*3+0] + (in[i*3+0] - in[j*3+0])*s;
out1[m*3+1] = in[j*3+1] + (in[i*3+1] - in[j*3+1])*s;
out1[m*3+2] = in[j*3+2] + (in[i*3+2] - in[j*3+2])*s;
rcVcopy(out2 + n*3, out1 + m*3);
m++;
n++;
// add the i'th point to the right polygon. Do NOT add points that are on the dividing line
// since these were already added above
if (d[i] > 0)
{
rcVcopy(out1 + m*3, in + i*3);
m++;
}
else if (d[i] < 0)
{
rcVcopy(out2 + n*3, in + i*3);
n++;
}
}
else // same side
{
// add the i'th point to the right polygon. Addition is done even for points on the dividing line
if (d[i] >= 0)
{
rcVcopy(out1 + m*3, in + i*3);
m++;
if (d[i] != 0)
continue;
}
rcVcopy(out2 + n*3, in + i*3);
n++;
}
}
*nout1 = m;
*nout2 = n;
}
static bool rasterizeTri(const float* v0, const float* v1, const float* v2,
const unsigned char area, rcHeightfield& hf,
const float* bmin, const float* bmax,
const float cs, const float ics, const float ich,
const int flagMergeThr)
{
const int w = hf.width;
const int h = hf.height;
float tmin[3], tmax[3];
const float by = bmax[1] - bmin[1];
// Calculate the bounding box of the triangle.
rcVcopy(tmin, v0);
rcVcopy(tmax, v0);
rcVmin(tmin, v1);
rcVmin(tmin, v2);
rcVmax(tmax, v1);
rcVmax(tmax, v2);
// If the triangle does not touch the bbox of the heightfield, skip the triagle.
if (!overlapBounds(bmin, bmax, tmin, tmax))
return true;
// Calculate the footprint of the triangle on the grid's y-axis
int y0 = (int)((tmin[2] - bmin[2])*ics);
int y1 = (int)((tmax[2] - bmin[2])*ics);
y0 = rcClamp(y0, 0, h-1);
y1 = rcClamp(y1, 0, h-1);
// Clip the triangle into all grid cells it touches.
float buf[7*3*4];
float *in = buf, *inrow = buf+7*3, *p1 = inrow+7*3, *p2 = p1+7*3;
rcVcopy(&in[0], v0);
rcVcopy(&in[1*3], v1);
rcVcopy(&in[2*3], v2);
int nvrow, nvIn = 3;
for (int y = y0; y <= y1; ++y)
{
// Clip polygon to row. Store the remaining polygon as well
const float cz = bmin[2] + y*cs;
dividePoly(in, nvIn, inrow, &nvrow, p1, &nvIn, cz+cs, 2);
rcSwap(in, p1);
if (nvrow < 3) continue;
// find the horizontal bounds in the row
float minX = inrow[0], maxX = inrow[0];
for (int i=1; i<nvrow; ++i)
{
if (minX > inrow[i*3]) minX = inrow[i*3];
if (maxX < inrow[i*3]) maxX = inrow[i*3];
}
int x0 = (int)((minX - bmin[0])*ics);
int x1 = (int)((maxX - bmin[0])*ics);
x0 = rcClamp(x0, 0, w-1);
x1 = rcClamp(x1, 0, w-1);
int nv, nv2 = nvrow;
for (int x = x0; x <= x1; ++x)
{
// Clip polygon to column. store the remaining polygon as well
const float cx = bmin[0] + x*cs;
dividePoly(inrow, nv2, p1, &nv, p2, &nv2, cx+cs, 0);
rcSwap(inrow, p2);
if (nv < 3) continue;
// Calculate min and max of the span.
float smin = p1[1], smax = p1[1];
for (int i = 1; i < nv; ++i)
{
smin = rcMin(smin, p1[i*3+1]);
smax = rcMax(smax, p1[i*3+1]);
}
smin -= bmin[1];
smax -= bmin[1];
// Skip the span if it is outside the heightfield bbox
if (smax < 0.0f) continue;
if (smin > by) continue;
// Clamp the span to the heightfield bbox.
if (smin < 0.0f) smin = 0;
if (smax > by) smax = by;
// Snap the span to the heightfield height grid.
unsigned short ismin = (unsigned short)rcClamp((int)floorf(smin * ich), 0, RC_SPAN_MAX_HEIGHT);
unsigned short ismax = (unsigned short)rcClamp((int)ceilf(smax * ich), (int)ismin+1, RC_SPAN_MAX_HEIGHT);
if (!addSpan(hf, x, y, ismin, ismax, area, flagMergeThr))
return false;
}
}
return true;
}
/// @par
///
/// No spans will be added if the triangle does not overlap the heightfield grid.
///
/// @see rcHeightfield
bool rcRasterizeTriangle(rcContext* ctx, const float* v0, const float* v1, const float* v2,
const unsigned char area, rcHeightfield& solid,
const int flagMergeThr)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_RASTERIZE_TRIANGLES);
const float ics = 1.0f/solid.cs;
const float ich = 1.0f/solid.ch;
if (!rasterizeTri(v0, v1, v2, area, solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr))
{
ctx->log(RC_LOG_ERROR, "rcRasterizeTriangle: Out of memory.");
return false;
}
return true;
}
/// @par
///
/// Spans will only be added for triangles that overlap the heightfield grid.
///
/// @see rcHeightfield
bool rcRasterizeTriangles(rcContext* ctx, const float* verts, const int /*nv*/,
const int* tris, const unsigned char* areas, const int nt,
rcHeightfield& solid, const int flagMergeThr)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_RASTERIZE_TRIANGLES);
const float ics = 1.0f/solid.cs;
const float ich = 1.0f/solid.ch;
// Rasterize triangles.
for (int i = 0; i < nt; ++i)
{
const float* v0 = &verts[tris[i*3+0]*3];
const float* v1 = &verts[tris[i*3+1]*3];
const float* v2 = &verts[tris[i*3+2]*3];
// Rasterize.
if (!rasterizeTri(v0, v1, v2, areas[i], solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr))
{
ctx->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
return false;
}
}
return true;
}
/// @par
///
/// Spans will only be added for triangles that overlap the heightfield grid.
///
/// @see rcHeightfield
bool rcRasterizeTriangles(rcContext* ctx, const float* verts, const int /*nv*/,
const unsigned short* tris, const unsigned char* areas, const int nt,
rcHeightfield& solid, const int flagMergeThr)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_RASTERIZE_TRIANGLES);
const float ics = 1.0f/solid.cs;
const float ich = 1.0f/solid.ch;
// Rasterize triangles.
for (int i = 0; i < nt; ++i)
{
const float* v0 = &verts[tris[i*3+0]*3];
const float* v1 = &verts[tris[i*3+1]*3];
const float* v2 = &verts[tris[i*3+2]*3];
// Rasterize.
if (!rasterizeTri(v0, v1, v2, areas[i], solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr))
{
ctx->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
return false;
}
}
return true;
}
/// @par
///
/// Spans will only be added for triangles that overlap the heightfield grid.
///
/// @see rcHeightfield
bool rcRasterizeTriangles(rcContext* ctx, const float* verts, const unsigned char* areas, const int nt,
rcHeightfield& solid, const int flagMergeThr)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_RASTERIZE_TRIANGLES);
const float ics = 1.0f/solid.cs;
const float ich = 1.0f/solid.ch;
// Rasterize triangles.
for (int i = 0; i < nt; ++i)
{
const float* v0 = &verts[(i*3+0)*3];
const float* v1 = &verts[(i*3+1)*3];
const float* v2 = &verts[(i*3+2)*3];
// Rasterize.
if (!rasterizeTri(v0, v1, v2, areas[i], solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr))
{
ctx->log(RC_LOG_ERROR, "rcRasterizeTriangles: Out of memory.");
return false;
}
}
return true;
}