ericw-tools/light/phong.cc

675 lines
24 KiB
C++

/* Copyright (C) 1996-1997 Id Software, Inc.
Copyright (C) 2017 Eric Wasylishen
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
See file, 'COPYING', for details.
*/
#include <light/phong.hh>
#include <light/light.hh> // for extended_texinfo_flags
#include <cstdint>
#include <iostream>
#include <common/polylib.hh>
#include <common/bsputils.hh>
#include <vector>
#include <map>
#include <unordered_map>
#include <set>
#include <algorithm>
#include <mutex>
#include <common/qvec.hh>
#include <tbb/parallel_for_each.h>
face_cache_t::face_cache_t() { };
face_cache_t::face_cache_t(const mbsp_t *bsp, const mface_t *face, const std::vector<face_normal_t> &normals)
: m_points(Face_Points(bsp, face)),
m_normals(normals),
m_plane(Face_Plane(bsp, face).vec4()),
m_edgePlanes(MakeInwardFacingEdgePlanes(m_points)),
m_pointsShrunkBy1Unit(ShrinkPoly(m_points, 1.0f)),
m_neighbours(NeighbouringFaces_new(bsp, face))
{
}
static neighbour_t FaceOverlapsEdge(const qvec3f &p0, const qvec3f &p1, const mbsp_t *bsp, const mface_t *f)
{
for (int edgeindex = 0; edgeindex < f->numedges; edgeindex++) {
const int v0 = Face_VertexAtIndex(bsp, f, edgeindex);
const int v1 = Face_VertexAtIndex(bsp, f, (edgeindex + 1) % f->numedges);
const qvec3f &v0point = Vertex_GetPos(bsp, v0);
const qvec3f &v1point = Vertex_GetPos(bsp, v1);
if (LinesOverlap(p0, p1, v0point, v1point)) {
return neighbour_t{f, v0point, v1point};
}
}
return neighbour_t{nullptr, qvec3f{}, qvec3f{}};
}
static void FacesOverlappingEdge_r(
const qvec3f &p0, const qvec3f &p1, const mbsp_t *bsp, int nodenum, std::vector<neighbour_t> *result)
{
if (nodenum < 0) {
// we don't do anything for leafs.
// faces are handled on nodes.
return;
}
const bsp2_dnode_t *node = BSP_GetNode(bsp, nodenum);
const dplane_t *plane = BSP_GetPlane(bsp, node->planenum);
const float p0dist = plane->distance_to_fast(p0);
const float p1dist = plane->distance_to_fast(p1);
if (fabs(p0dist) < 0.1 && fabs(p1dist) < 0.1) {
// check all faces on this node.
for (int i = 0; i < node->numfaces; i++) {
const mface_t *face = BSP_GetFace(bsp, node->firstface + i);
const auto neighbour = FaceOverlapsEdge(p0, p1, bsp, face);
if (neighbour.face != nullptr) {
result->push_back(neighbour);
}
}
}
// recurse down front.
// NOTE: also do this if either point almost on-node.
// It could be on this plane, but also on some other plane further down
// the front (or back) side.
if (p0dist > -0.1 || p1dist > -0.1) {
FacesOverlappingEdge_r(p0, p1, bsp, node->children[0], result);
}
// recurse down back
if (p0dist < 0.1 || p1dist < 0.1) {
FacesOverlappingEdge_r(p0, p1, bsp, node->children[1], result);
}
}
/**
* Returns faces which have an edge that overlaps the given p0-p1 edge.
* Uses hull 0.
*/
inline std::vector<neighbour_t> FacesOverlappingEdge(
const qvec3f &p0, const qvec3f &p1, const mbsp_t *bsp, const dmodelh2_t *model)
{
std::vector<neighbour_t> result;
FacesOverlappingEdge_r(p0, p1, bsp, model->headnode[0], &result);
return result;
}
std::vector<neighbour_t> NeighbouringFaces_new(const mbsp_t *bsp, const mface_t *face)
{
std::vector<neighbour_t> result;
std::set<const mface_t *> used_faces;
for (int i = 0; i < face->numedges; i++) {
const qvec3f &p0 = Face_PointAtIndex(bsp, face, i);
const qvec3f &p1 = Face_PointAtIndex(bsp, face, (i + 1) % face->numedges);
std::vector<neighbour_t> tmp = FacesOverlappingEdge(p0, p1, bsp, &bsp->dmodels[0]);
// ensure the neighbour_t edges are pointing the same direction as the p0->p1 edge
// (modifies them inplace)
const qvec3f p0p1dir = qv::normalize(p1 - p0);
for (auto &neighbour : tmp) {
qvec3f neighbourDir = qv::normalize(neighbour.p1 - neighbour.p0);
float dp = qv::dot(neighbourDir, p0p1dir); // should really be 1 or -1
if (dp < 0) {
std::swap(neighbour.p0, neighbour.p1);
// float new_dp = qv::dot(qv::normalize(neighbour.p1 - neighbour.p0), p0p1dir);
// Q_assert(new_dp > 0);
}
}
for (const auto &neighbour : tmp) {
if (neighbour.face != face && used_faces.find(neighbour.face) == used_faces.end()) {
used_faces.insert(neighbour.face);
result.push_back(neighbour);
}
}
}
return result;
}
/* return 0 if either vector is zero-length */
static float AngleBetweenVectors(const qvec3f &d1, const qvec3f &d2)
{
float length_product = (qv::length(d1) * qv::length(d2));
if (length_product == 0)
return 0;
float cosangle = qv::dot(d1, d2) / length_product;
if (cosangle < -1)
cosangle = -1;
if (cosangle > 1)
cosangle = 1;
float angle = acos(cosangle);
return angle;
}
/* returns the angle between vectors p2->p1 and p2->p3 */
static float AngleBetweenPoints(const qvec3f &p1, const qvec3f &p2, const qvec3f &p3)
{
const qvec3f d1 = p1 - p2;
const qvec3f d2 = p3 - p2;
float result = AngleBetweenVectors(d1, d2);
return result;
}
static bool s_builtPhongCaches;
static std::unordered_map<const mface_t *, std::vector<face_normal_t>> vertex_normals;
static std::map<const mface_t *, std::set<const mface_t *>> smoothFaces;
static std::map<int, std::vector<const mface_t *>> vertsToFaces;
static std::map<int, std::vector<const mface_t *>> planesToFaces;
static edgeToFaceMap_t EdgeToFaceMap;
static std::vector<face_cache_t> FaceCache;
void ResetPhong()
{
s_builtPhongCaches = false;
vertex_normals = {};
smoothFaces = {};
vertsToFaces = {};
planesToFaces = {};
EdgeToFaceMap = {};
FaceCache = {};
}
std::vector<const mface_t *> FacesUsingVert(int vertnum)
{
const auto &vertsToFaces_const = vertsToFaces;
auto it = vertsToFaces_const.find(vertnum);
if (it != vertsToFaces_const.end())
return it->second;
return {};
}
const edgeToFaceMap_t &GetEdgeToFaceMap()
{
Q_assert(s_builtPhongCaches);
return EdgeToFaceMap;
}
// Uses `smoothFaces` static var
bool FacesSmoothed(const mface_t *f1, const mface_t *f2)
{
Q_assert(s_builtPhongCaches);
const auto &facesIt = smoothFaces.find(f1);
if (facesIt == smoothFaces.end())
return false;
const std::set<const mface_t *> &faceSet = facesIt->second;
if (faceSet.find(f2) == faceSet.end())
return false;
return true;
}
const std::set<const mface_t *> &GetSmoothFaces(const mface_t *face)
{
Q_assert(s_builtPhongCaches);
static std::set<const mface_t *> empty;
const auto it = smoothFaces.find(face);
if (it == smoothFaces.end())
return empty;
return it->second;
}
const std::vector<const mface_t *> &GetPlaneFaces(const mface_t *face)
{
Q_assert(s_builtPhongCaches);
static std::vector<const mface_t *> empty;
const auto it = planesToFaces.find(face->planenum);
if (it == planesToFaces.end())
return empty;
return it->second;
}
// Adapted from https://github.com/NVIDIAGameWorks/donut/blob/main/src/engine/GltfImporter.cpp#L684
std::tuple<qvec3f, qvec3f> compute_tangents(
const std::array<qvec3f, 3> &positions, const std::array<qvec2f, 3> &tex_coords)
{
qvec3f dPds = positions[1] - positions[0];
qvec3f dPdt = positions[2] - positions[0];
qvec3f dTds = tex_coords[1] - tex_coords[0];
qvec3f dTdt = tex_coords[2] - tex_coords[0];
float r = 1.0f / (dTds[0] * dTdt[1] - dTds[1] * dTdt[0]);
qvec3f tangent = (dPds * dTdt[1] - dPdt * dTds[1]) * r;
qvec3f bitangent = (dPdt * dTds[0] - dPds * dTdt[0]) * r;
return {qv::normalize(tangent), qv::normalize(bitangent)};
}
/* access the final phong-shaded vertex normal */
const face_normal_t &GetSurfaceVertexNormal(const mbsp_t *bsp, const mface_t *f, const int vertindex)
{
Q_assert(s_builtPhongCaches);
// handle degenerate faces
const auto it = vertex_normals.find(f);
if (it == vertex_normals.end()) {
static const face_normal_t empty{};
return empty;
}
const auto &face_normals_vec = it->second;
return face_normals_vec.at(vertindex);
}
const mface_t *Face_EdgeIndexSmoothed(const mbsp_t *bsp, const mface_t *f, const int edgeindex)
{
Q_assert(s_builtPhongCaches);
const int v0 = Face_VertexAtIndex(bsp, f, edgeindex);
const int v1 = Face_VertexAtIndex(bsp, f, (edgeindex + 1) % f->numedges);
auto it = EdgeToFaceMap.find(std::make_pair(v1, v0));
if (it != EdgeToFaceMap.end()) {
for (const mface_t *neighbour : it->second) {
if (neighbour == f) {
// Invalid face, e.g. with vertex numbers: [0, 1, 0, 2]
continue;
}
const bool sameplane = (neighbour->planenum == f->planenum && neighbour->side == f->side);
// Check if these faces are smoothed or on the same plane
if (!(FacesSmoothed(f, neighbour) || sameplane)) {
continue;
}
return neighbour;
}
}
return nullptr;
#if 0
if (smoothFaces.find(f) == smoothFaces.end()) {
return nullptr;
}
int v0 = Face_VertexAtIndex(bsp, f, edgeindex);
int v1 = Face_VertexAtIndex(bsp, f, (edgeindex + 1) % f->numedges);
const auto &v0_faces = vertsToFaces.at(v0);
const auto &v1_faces = vertsToFaces.at(v1);
// find a face f2 that has both verts v0 and v1
for (auto f2 : v0_faces) {
if (f2 == f)
continue;
if (find(v1_faces.begin(), v1_faces.end(), f2) != v1_faces.end()) {
const auto &f_smoothfaces = smoothFaces.at(f);
bool smoothed = (f_smoothfaces.find(f2) != f_smoothfaces.end());
return smoothed ? f2 : nullptr;
}
}
return nullptr;
#endif
}
static edgeToFaceMap_t MakeEdgeToFaceMap(const mbsp_t *bsp)
{
edgeToFaceMap_t result;
for (auto &f : bsp->dfaces) {
// walk edges
for (int j = 0; j < f.numedges; j++) {
const int v0 = Face_VertexAtIndex(bsp, &f, j);
const int v1 = Face_VertexAtIndex(bsp, &f, (j + 1) % f.numedges);
if (v0 == v1) {
// ad_swampy.bsp has faces with repeated verts...
continue;
}
const auto edge = std::make_pair(v0, v1);
auto &edgeFacesRef = result[edge];
if (find(begin(edgeFacesRef), end(edgeFacesRef), &f) != end(edgeFacesRef)) {
// another sort of degenerate face where the same edge A->B appears more than once on the face
continue;
}
edgeFacesRef.push_back(&f);
}
}
return result;
}
static std::vector<face_normal_t> Face_VertexNormals(const mbsp_t *bsp, const mface_t *face)
{
std::vector<face_normal_t> normals(face->numedges);
tbb::parallel_for(0, face->numedges, [&](size_t i) { normals[i] = GetSurfaceVertexNormal(bsp, face, i); });
return normals;
}
#include <common/parallel.hh>
static std::vector<face_cache_t> MakeFaceCache(const mbsp_t *bsp)
{
logging::funcheader();
std::vector<face_cache_t> result(bsp->dfaces.size());
logging::parallel_for(static_cast<size_t>(0), bsp->dfaces.size(), [&](size_t i) {
auto &face = bsp->dfaces[i];
result[i] = face_cache_t(bsp, &bsp->dfaces[i], Face_VertexNormals(bsp, &face));
});
return result;
}
/**
* Q2: Returns nonzero if phong is requested on this face, in which case that is
* the face tag to smooth with. Otherwise returns 0.
*/
int Q2_FacePhongValue(const mbsp_t *bsp, const mface_t *face)
{
const mtexinfo_t *texinfo = BSP_GetTexinfo(bsp, face->texinfo);
if (texinfo != nullptr) {
// FIXME: would be more convenient if common code loaded texinfo file
// so we could access these in mtexinfo_t rather than extended_texinfo_flags
if (auto phong_group = extended_texinfo_flags[face->texinfo].phong_group) {
// Q1 _phong_group syntax (also works in Q2 maps)
return phong_group;
}
if (texinfo->value != 0 && ((texinfo->flags.native_q2 & Q2_SURF_LIGHT) == 0)) {
return texinfo->value;
}
}
return 0;
}
inline bool isDegenerate(const qvec3f &a, const qvec3f &b, const qvec3f &c)
{
float lengths[] = {qv::distance(a, b), qv::distance(b, c), qv::distance(c, a)};
for (size_t i = 0; i < 3; i++) {
if (lengths[i] == lengths[(i + 1) % 3] + lengths[(i + 2) % 3]) {
return true;
}
}
return false;
}
void CalculateVertexNormals(const mbsp_t *bsp)
{
logging::funcheader();
Q_assert(!s_builtPhongCaches);
s_builtPhongCaches = true;
EdgeToFaceMap = MakeEdgeToFaceMap(bsp);
// read _phong and _phong_angle from entities for compatibility with other qbsp's, at the expense of no
// support on func_detail/func_group
for (size_t i = 0; i < bsp->dmodels.size(); i++) {
const modelinfo_t *info = ModelInfoForModel(bsp, i);
const uint8_t phongangle_byte = (uint8_t)std::clamp((int)rint(info->getResolvedPhongAngle()), 0, 255);
if (!phongangle_byte)
continue;
for (int j = info->model->firstface; j < info->model->firstface + info->model->numfaces; j++) {
const mface_t *f = BSP_GetFace(bsp, j);
extended_texinfo_flags[f->texinfo].phong_angle = phongangle_byte;
}
}
for (auto &f : bsp->dfaces) {
// build "plane -> faces" map
planesToFaces[f.planenum].push_back(&f);
// build "vert index -> faces" map
for (size_t j = 0; j < f.numedges; j++) {
const int v = Face_VertexAtIndex(bsp, &f, j);
vertsToFaces[v].push_back(&f);
}
}
// build the "face -> faces to smooth with" map
for (auto &f : bsp->dfaces) {
// Q2 shading groups
const int f_phongValue = Q2_FacePhongValue(bsp, &f);
// Q1 phong angle stuff
auto *f_texinfo = Face_Texinfo(bsp, &f);
const auto f_points = Face_Points(bsp, &f);
const qvec3f f_norm = Face_Normal(bsp, &f);
const qplane3f f_plane = Face_Plane(bsp, &f);
// any face normal within this many degrees can be smoothed with this face
float f_phong_angle = extended_texinfo_flags[f.texinfo].phong_angle;
if (f_phong_angle == 0 && f_phongValue != 0) {
// if Q2 style phong is requested, but Q1 is not in use, set the default phong angle
f_phong_angle = modelinfo_t::DEFAULT_PHONG_ANGLE;
}
float f_phong_angle_concave = extended_texinfo_flags[f.texinfo].phong_angle_concave;
if (f_phong_angle_concave == 0) {
f_phong_angle_concave = f_phong_angle;
}
const bool f_wants_phong = (f_phong_angle || f_phong_angle_concave);
if (!f_wants_phong)
continue;
for (int j = 0; j < f.numedges; j++) {
const int v = Face_VertexAtIndex(bsp, &f, j);
// walk over all faces incident to f (we will walk over neighbours multiple times, doesn't matter)
for (const mface_t *f2 : vertsToFaces[v]) {
if (f2 == &f)
continue;
// FIXME: factor out and share with above?
const int f2_phongValue = Q2_FacePhongValue(bsp, f2);
float f2_phong_angle = extended_texinfo_flags[f2->texinfo].phong_angle;
if (f2_phong_angle == 0 && f2_phongValue != 0) {
// if Q2 style phong is requested, but Q1 is not in use, set the default phong angle
f2_phong_angle = modelinfo_t::DEFAULT_PHONG_ANGLE;
}
float f2_phong_angle_concave = extended_texinfo_flags[f2->texinfo].phong_angle_concave;
if (f2_phong_angle_concave == 0) {
f2_phong_angle_concave = f2_phong_angle;
}
const bool f2_wants_phong = (f2_phong_angle || f2_phong_angle_concave);
if (!f2_wants_phong)
continue;
auto *f2_texinfo = Face_Texinfo(bsp, f2);
if (f2_texinfo != nullptr && f_texinfo != nullptr) {
if (!bsp->loadversion->game->surfflags_may_phong(f_texinfo->flags, f2_texinfo->flags)) {
// phong may be blocked by the gamedef, e.g. warping and non-warping never phong
continue;
}
}
const auto f2_points = Face_Points(bsp, f2);
const qvec3f f2_centroid = qv::PolyCentroid(f2_points.begin(), f2_points.end());
const qvec3f f2_norm = Face_Normal(bsp, f2);
const float cosangle = qv::dot(f_norm, f2_norm);
const bool concave = f_plane.distance_to(f2_centroid) > 0.1;
const float f_threshold = concave ? f_phong_angle_concave : f_phong_angle;
const float f2_threshold = concave ? f2_phong_angle_concave : f2_phong_angle;
const float min_threshold = std::min(f_threshold, f2_threshold);
const float cosmaxangle = cos(DEG2RAD(min_threshold));
if (f_phongValue != f2_phongValue) {
// mismatched smoothing groups never phong
continue;
}
// check the angle between the face normals
if (cosangle >= cosmaxangle) {
smoothFaces[&f].insert(f2);
}
}
}
}
logging::print(logging::flag::VERBOSE, " {} faces for smoothing\n", smoothFaces.size());
// finally do the smoothing for each face
std::mutex normalsMutex;
logging::parallel_for_each(bsp->dfaces, [bsp, &normalsMutex](const mface_t &f) {
if (f.numedges < 3) {
logging::funcprint("face {} is degenerate with {} edges\n", Face_GetNum(bsp, &f), f.numedges);
for (int j = 0; j < f.numedges; j++) {
logging::print(" vert at {}\n", Face_PointAtIndex(bsp, &f, j));
}
return;
}
const qvec3f f_norm = Face_Normal(bsp, &f); // get the face normal
// face tangent
auto t1 = TexSpaceToWorld(bsp, &f);
std::tuple<qvec3f, qvec3f> tangents(t1.col(0).xyz(), qv::normalize(t1.col(1).xyz()));
// gather up f and neighboursToSmooth
std::vector<const mface_t *> fPlusNeighbours;
fPlusNeighbours.push_back(&f);
auto neighboursIt = smoothFaces.find(&f);
if (neighboursIt != smoothFaces.end()) {
const auto &neighboursToSmooth = neighboursIt->second;
std::copy(neighboursToSmooth.begin(), neighboursToSmooth.end(), std::back_inserter(fPlusNeighbours));
}
// global vertex index -> smoothed normal
std::unordered_map<int, face_normal_t> smoothedNormals;
// walk fPlusNeighbours
for (auto f2 : fPlusNeighbours) {
const auto f2_poly = Face_Points(bsp, f2);
const float f2_area = qv::PolyArea(f2_poly.begin(), f2_poly.end());
const qvec3f f2_norm = Face_Normal(bsp, f2);
// f2 face tangent
auto t2 = TexSpaceToWorld(bsp, f2);
std::tuple<qvec3f, qvec3f> f2_tangents(t2.col(0).xyz(), qv::normalize(t2.col(1).xyz()));
// walk the vertices of f2, and add their contribution to smoothedNormals
for (int j = 0; j < f2->numedges; j++) {
const int prev_vert_num = Face_VertexAtIndex(bsp, f2, ((j - 1) + f2->numedges) % f2->numedges);
const int curr_vert_num = Face_VertexAtIndex(bsp, f2, j);
const int next_vert_num = Face_VertexAtIndex(bsp, f2, (j + 1) % f2->numedges);
const qvec3f &prev_vert_pos = Vertex_GetPos(bsp, prev_vert_num);
const qvec3f &curr_vert_pos = Vertex_GetPos(bsp, curr_vert_num);
const qvec3f &next_vert_pos = Vertex_GetPos(bsp, next_vert_num);
const float angle_radians = AngleBetweenPoints(prev_vert_pos, curr_vert_pos, next_vert_pos);
float weight = f2_area * angle_radians;
if (!std::isfinite(weight)) {
// TODO: not sure if needed?
weight = 0;
}
auto &n = smoothedNormals[curr_vert_num];
n.normal += f2_norm * weight;
n.tangent += std::get<0>(f2_tangents) * weight;
n.bitangent += std::get<1>(f2_tangents) * weight;
}
}
// normalize vertex normals (NOTE: updates smoothedNormals map)
for (auto &pair : smoothedNormals) {
face_normal_t &vertNormal = pair.second;
if (0 == qv::length(vertNormal.normal)) {
// this happens when there are colinear vertices, which give zero-area triangles,
// so there is no contribution to the normal of the triangle in the middle of the
// line. Not really an error, just set it to use the face normal.
#if 0
const int vertIndex = pair.first;
logging::print("Failed to calculate normal for vertex {} at ({} {} {})\n",
vertIndex,
bsp->dvertexes[vertIndex].point[0],
bsp->dvertexes[vertIndex].point[1],
bsp->dvertexes[vertIndex].point[2]);
#endif
vertNormal = {f_norm, std::get<0>(tangents), std::get<1>(tangents)};
} else {
vertNormal = {qv::normalize(vertNormal.normal), qv::normalize(vertNormal.tangent),
qv::normalize(vertNormal.bitangent)};
}
// FIXME: why
if (std::isnan(vertNormal.tangent[0])) {
vertNormal.tangent = std::get<0>(tangents);
if (std::isnan(vertNormal.tangent[0])) {
vertNormal.tangent = {0, 0, 0};
}
}
if (std::isnan(vertNormal.bitangent[0])) {
vertNormal.bitangent = std::get<1>(tangents);
if (std::isnan(vertNormal.bitangent[0])) {
vertNormal.bitangent = {0, 0, 0};
}
}
}
// sanity check
if (neighboursIt != smoothFaces.end()) {
const auto &neighboursToSmooth = neighboursIt->second;
if (!neighboursToSmooth.size()) {
for (auto &vertIndexNormalPair : smoothedNormals) {
Q_assert(qv::epsilonEqual(vertIndexNormalPair.second.normal, f_norm, (float)LIGHT_EQUAL_EPSILON));
}
}
}
// now, record all of the smoothed normals that are actually part of `f`
for (int j = 0; j < f.numedges; j++) {
int v = Face_VertexAtIndex(bsp, &f, j);
Q_assert(smoothedNormals.find(v) != smoothedNormals.end());
normalsMutex.lock();
vertex_normals[&f].push_back(smoothedNormals[v]);
normalsMutex.unlock();
}
});
FaceCache = MakeFaceCache(bsp);
}
const face_cache_t &FaceCacheForFNum(int fnum)
{
Q_assert(s_builtPhongCaches);
return FaceCache.at(fnum);
}