qzdoom/src/polyrenderer/scene/poly_cull.cpp
2017-05-14 08:55:30 +02:00

332 lines
9.4 KiB
C++

/*
** Potential visible set (PVS) handling
** Copyright (c) 2016 Magnus Norddahl
**
** 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.
**
*/
#include <stdlib.h>
#include "templates.h"
#include "doomdef.h"
#include "sbar.h"
#include "r_data/r_translate.h"
#include "poly_cull.h"
#include "polyrenderer/poly_renderer.h"
void PolyCull::CullScene(const TriMatrix &worldToClip, const PolyClipPlane &portalClipPlane)
{
PvsSectors.clear();
PortalClipPlane = portalClipPlane;
// Cull front to back
FirstSkyHeight = true;
MaxCeilingHeight = 0.0;
MinFloorHeight = 0.0;
if (level.nodes.Size() == 0)
CullSubsector(&level.subsectors[0]);
else
CullNode(level.HeadNode());
}
void PolyCull::CullNode(void *node)
{
while (!((size_t)node & 1)) // Keep going until found a subsector
{
node_t *bsp = (node_t *)node;
// Decide which side the view point is on.
int side = PointOnSide(PolyRenderer::Instance()->Viewpoint.Pos, bsp);
// Recursively divide front space (toward the viewer).
CullNode(bsp->children[side]);
// Possibly divide back space (away from the viewer).
side ^= 1;
if (!CheckBBox(bsp->bbox[side]))
return;
node = bsp->children[side];
}
subsector_t *sub = (subsector_t *)((uint8_t *)node - 1);
CullSubsector(sub);
}
void PolyCull::CullSubsector(subsector_t *sub)
{
// Check if subsector is clipped entirely by the portal clip plane
bool visible = false;
for (uint32_t i = 0; i < sub->numlines; i++)
{
seg_t *line = &sub->firstline[i];
if (PortalClipPlane.A * line->v1->fX() + PortalClipPlane.B * line->v1->fY() + PortalClipPlane.D > 0.0)
{
visible = true;
break;
}
}
if (!visible)
return;
// Update sky heights for the scene
if (!FirstSkyHeight)
{
MaxCeilingHeight = MAX(MaxCeilingHeight, sub->sector->ceilingplane.Zat0());
MinFloorHeight = MIN(MinFloorHeight, sub->sector->floorplane.Zat0());
}
else
{
MaxCeilingHeight = sub->sector->ceilingplane.Zat0();
MinFloorHeight = sub->sector->floorplane.Zat0();
FirstSkyHeight = false;
}
// Mark that we need to render this
PvsSectors.push_back(sub);
// Update culling info for further bsp clipping
for (uint32_t i = 0; i < sub->numlines; i++)
{
seg_t *line = &sub->firstline[i];
if ((line->sidedef == nullptr || !(line->sidedef->Flags & WALLF_POLYOBJ)) && line->backsector == nullptr)
{
// Skip lines not facing viewer
DVector2 pt1 = line->v1->fPos() - PolyRenderer::Instance()->Viewpoint.Pos;
DVector2 pt2 = line->v2->fPos() - PolyRenderer::Instance()->Viewpoint.Pos;
if (pt1.Y * (pt1.X - pt2.X) + pt1.X * (pt2.Y - pt1.Y) >= 0)
continue;
// Skip line if entirely behind portal clipping plane
if ((PortalClipPlane.A * line->v1->fX() + PortalClipPlane.B * line->v1->fY() + PortalClipPlane.D <= 0.0) ||
(PortalClipPlane.A * line->v2->fX() + PortalClipPlane.B * line->v2->fY() + PortalClipPlane.D <= 0.0))
{
continue;
}
angle_t angle1, angle2;
if (GetAnglesForLine(line->v1->fX(), line->v1->fY(), line->v2->fX(), line->v2->fY(), angle1, angle2))
{
MarkSegmentCulled(angle1, angle2);
}
}
}
}
void PolyCull::ClearSolidSegments()
{
SolidSegments.clear();
}
void PolyCull::InvertSegments()
{
TempInvertSolidSegments.swap(SolidSegments);
ClearSolidSegments();
angle_t cur = 0;
for (const auto &segment : TempInvertSolidSegments)
{
if (cur < segment.Start)
MarkSegmentCulled(cur, segment.Start - 1);
cur = segment.End + 1;
}
if (cur < ANGLE_MAX)
MarkSegmentCulled(cur, ANGLE_MAX);
}
bool PolyCull::IsSegmentCulled(angle_t startAngle, angle_t endAngle) const
{
if (startAngle > endAngle)
{
return IsSegmentCulled(startAngle, ANGLE_MAX) && IsSegmentCulled(0, endAngle);
}
for (const auto &segment : SolidSegments)
{
if (startAngle >= segment.Start && endAngle <= segment.End)
return true;
else if (endAngle < segment.Start)
return false;
}
return false;
}
void PolyCull::MarkSegmentCulled(angle_t startAngle, angle_t endAngle)
{
if (startAngle > endAngle)
{
MarkSegmentCulled(startAngle, ANGLE_MAX);
MarkSegmentCulled(0, endAngle);
return;
}
int count = (int)SolidSegments.size();
int cur = 0;
while (cur < count)
{
if (SolidSegments[cur].Start <= startAngle && SolidSegments[cur].End >= endAngle) // Already fully marked
{
return;
}
else if (SolidSegments[cur].End >= startAngle && SolidSegments[cur].Start <= endAngle) // Merge segments
{
// Find last segment
int merge = cur;
while (merge + 1 != count && SolidSegments[merge + 1].Start <= endAngle)
merge++;
// Apply new merged range
SolidSegments[cur].Start = MIN(SolidSegments[cur].Start, startAngle);
SolidSegments[cur].End = MAX(SolidSegments[merge].End, endAngle);
// Remove additional segments we merged with
if (merge > cur)
SolidSegments.erase(SolidSegments.begin() + (cur + 1), SolidSegments.begin() + (merge + 1));
return;
}
else if (SolidSegments[cur].Start > startAngle) // Insert new segment
{
SolidSegments.insert(SolidSegments.begin() + cur, { startAngle, endAngle });
return;
}
cur++;
}
SolidSegments.push_back({ startAngle, endAngle });
#if 0
count = (int)SolidSegments.size();
for (int i = 1; i < count; i++)
{
if (SolidSegments[i - 1].Start >= SolidSegments[i].Start ||
SolidSegments[i - 1].End >= SolidSegments[i].Start ||
SolidSegments[i - 1].End + 1 == SolidSegments[i].Start ||
SolidSegments[i].Start > SolidSegments[i].End)
{
I_FatalError("MarkSegmentCulled is broken!");
}
}
#endif
}
int PolyCull::PointOnSide(const DVector2 &pos, const node_t *node)
{
return DMulScale32(FLOAT2FIXED(pos.Y) - node->y, node->dx, node->x - FLOAT2FIXED(pos.X), node->dy) > 0;
}
bool PolyCull::CheckBBox(float *bspcoord)
{
// Occlusion test using solid segments:
static const uint8_t checkcoord[12][4] =
{
{ 3,0,2,1 },
{ 3,0,2,0 },
{ 3,1,2,0 },
{ 0 },
{ 2,0,2,1 },
{ 0,0,0,0 },
{ 3,1,3,0 },
{ 0 },
{ 2,0,3,1 },
{ 2,1,3,1 },
{ 2,1,3,0 }
};
// Find the corners of the box that define the edges from current viewpoint.
const auto &viewpoint = PolyRenderer::Instance()->Viewpoint;
int boxpos = (viewpoint.Pos.X <= bspcoord[BOXLEFT] ? 0 : viewpoint.Pos.X < bspcoord[BOXRIGHT] ? 1 : 2) +
(viewpoint.Pos.Y >= bspcoord[BOXTOP] ? 0 : viewpoint.Pos.Y > bspcoord[BOXBOTTOM] ? 4 : 8);
if (boxpos == 5) return true;
const uint8_t *check = checkcoord[boxpos];
angle_t angle1 = PointToPseudoAngle(bspcoord[check[0]], bspcoord[check[1]]);
angle_t angle2 = PointToPseudoAngle(bspcoord[check[2]], bspcoord[check[3]]);
return !IsSegmentCulled(angle2, angle1);
}
bool PolyCull::GetAnglesForLine(double x1, double y1, double x2, double y2, angle_t &angle1, angle_t &angle2) const
{
angle2 = PointToPseudoAngle(x1, y1);
angle1 = PointToPseudoAngle(x2, y2);
return !IsSegmentCulled(angle1, angle2);
}
void PolyCull::MarkViewFrustum()
{
// Clips things outside the viewing frustum.
auto &viewpoint = PolyRenderer::Instance()->Viewpoint;
auto &viewwindow = PolyRenderer::Instance()->Viewwindow;
double tilt = fabs(viewpoint.Angles.Pitch.Degrees);
if (tilt > 46.0) // If the pitch is larger than this you can look all around
return;
double floatangle = 2.0 + (45.0 + ((tilt / 1.9)))*viewpoint.FieldOfView.Degrees*48.0 / AspectMultiplier(viewwindow.WidescreenRatio) / 90.0;
angle_t a1 = DAngle(floatangle).BAMs();
if (a1 < ANGLE_180)
{
MarkSegmentCulled(AngleToPseudo(viewpoint.Angles.Yaw.BAMs() + a1), AngleToPseudo(viewpoint.Angles.Yaw.BAMs() - a1));
}
}
//-----------------------------------------------------------------------------
//
// ! Returns the pseudoangle between the line p1 to (infinity, p1.y) and the
// line from p1 to p2. The pseudoangle has the property that the ordering of
// points by true angle around p1 and ordering of points by pseudoangle are the
// same.
//
// For clipping exact angles are not needed. Only the ordering matters.
// This is about as fast as the fixed point R_PointToAngle2 but without
// the precision issues associated with that function.
//
//-----------------------------------------------------------------------------
angle_t PolyCull::PointToPseudoAngle(double x, double y)
{
const auto &viewpoint = PolyRenderer::Instance()->Viewpoint;
double vecx = x - viewpoint.Pos.X;
double vecy = y - viewpoint.Pos.Y;
if (vecx == 0 && vecy == 0)
{
return 0;
}
else
{
double result = vecy / (fabs(vecx) + fabs(vecy));
if (vecx < 0)
{
result = 2. - result;
}
return xs_Fix<30>::ToFix(result);
}
}
angle_t PolyCull::AngleToPseudo(angle_t ang)
{
double vecx = cos(ang * M_PI / ANGLE_180);
double vecy = sin(ang * M_PI / ANGLE_180);
double result = vecy / (fabs(vecx) + fabs(vecy));
if (vecx < 0)
{
result = 2.f - result;
}
return xs_Fix<30>::ToFix(result);
}