RingRacers/src/p_test.cpp
2025-09-30 17:05:35 -05:00

135 lines
3.2 KiB
C++

// DR. ROBOTNIK'S RING RACERS
//-----------------------------------------------------------------------------
// Copyright (C) 2025 by James Robert Roman
// Copyright (C) 2025 by Kart Krew
//
// This program is free software distributed under the
// terms of the GNU General Public License, version 2.
// See the 'LICENSE' file for more details.
//-----------------------------------------------------------------------------
#include <optional>
#include <vector>
#include "math/fixed.hpp"
#include "p_sweep.hpp"
#include "p_local.h"
#include "g_demo.h"
#include "r_main.h"
namespace
{
std::vector<line_t*> g_lines;
};
void P_TestLine(line_t* ld)
{
g_lines.emplace_back(ld);
}
line_t* P_SweepTestLines(fixed_t ax, fixed_t ay, fixed_t bx, fixed_t by, fixed_t r, vector2_t* return_normal)
{
extern consvar_t cv_showgremlins;
using namespace srb2::math;
using namespace srb2::sweep;
struct Collision
{
unit z;
vec2 normal;
line_t* ld;
bool operator<(const Collision& b) const { return z < b.z; }
};
std::optional<Collision> collision;
LineSegment<Fixed> l{{ax, ay}, {bx, by}};
AABBvsLine sweep{r, l};
for (line_t* ld : g_lines)
{
LineSegment<Fixed> ls{{ld->v1->x, ld->v1->y}, {ld->v2->x, ld->v2->y}};
Result rs = sweep(ls);
if (rs.hit)
{
if (!collision || rs.hit->z < collision->z)
{
collision = {rs.hit->z, rs.hit->n, ld};
}
}
}
if (!collision)
{
line_t *line = nullptr;
if (!g_lines.empty() && !G_CompatLevel(0x000E))
{
// FIXME: This condition is a failsafe!
// SlopeAABBvsLine::vs_slope can sometimes report
// no collision despite P_CheckPosition saying otherwise.
// (Generally related to infinitesimal numbers or overflows.)
// When it reports no collision, that means no line and
// no normals to base the collision off of.
// Here we provide the last line checked and normals based on
// the line and the player's momentum angle.
// But the proper fix would be to make vs_slope work!!
line = g_lines.back();
angle_t lineangle = line->angle;
angle_t mobjangle = R_PointToAngle2(ax, ay, bx, by);
angle_t diff = lineangle - mobjangle;
lineangle += diff > ANGLE_180 ? -ANGLE_90 : ANGLE_90;
return_normal->x = FINECOSINE((lineangle >> ANGLETOFINESHIFT) & FINEMASK);
return_normal->y = FINESINE((lineangle >> ANGLETOFINESHIFT) & FINEMASK);
// Moving the gremlin debug here so that it
// still fires even when the workaround is used.
if (cv_showgremlins.value)
{
mobj_t *mo = g_tm.thing;
if (mo)
{
mobj_t *x = P_SpawnMobj(mo->x, mo->y, mo->z, MT_THOK);
x->frame = FF_FULLBRIGHT | FF_ADD;
x->renderflags = RF_ALWAYSONTOP;
x->color = SKINCOLOR_RED;
CONS_Printf(
"GREMLIN: leveltime=%u x=%f y=%f z=%f momx=%f momy=%f momz=%f\n",
leveltime,
FixedToFloat(mo->x),
FixedToFloat(mo->y),
FixedToFloat(mo->z),
FixedToFloat(mo->momx),
FixedToFloat(mo->momy),
FixedToFloat(mo->momz)
);
}
}
}
g_lines.clear();
return line;
}
g_lines.clear();
return_normal->x = Fixed {collision->normal.x};
return_normal->y = Fixed {collision->normal.y};
return collision->ld;
}
void P_ClearTestLines(void)
{
g_lines.clear();
}