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blender-archive/source/blender/render/intern/texture_margin.cc
Hans Goudey 7b091fbb94 Cleanup: Remove includes from DerivedMesh header
Headers should only include other headers when absolutely necessary,
to avoid unnecessary dependencies and increasing compile times.
To make this change simpler, three DerivedMesh functions with a single
use were removed.
2022-05-15 20:27:28 +02:00

619 lines
20 KiB
C++

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright 2001-2002 NaN Holding BV. All rights reserved. */
/** \file
* \ingroup render
*/
#include "BLI_assert.h"
#include "BLI_math_geom.h"
#include "BLI_math_vec_types.hh"
#include "BLI_math_vector.hh"
#include "BLI_vector.hh"
#include "BKE_DerivedMesh.h"
#include "BKE_customdata.h"
#include "BKE_mesh.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "IMB_imbuf.h"
#include "IMB_imbuf_types.h"
#include "MEM_guardedalloc.h"
#include "zbuf.h" // for rasterizer
#include "RE_texture_margin.h"
#include <algorithm>
#include <cmath>
#include <valarray>
namespace blender::render::texturemargin {
/**
* The map class contains both a pixel map which maps out polygon indices for all UV-polygons and
* adjacency tables.
*/
class TextureMarginMap {
static const int directions[8][2];
static const int distances[8];
/** Maps UV-edges to their corresponding UV-edge. */
Vector<int> loop_adjacency_map_;
/** Maps UV-edges to their corresponding polygon. */
Vector<int> loop_to_poly_map_;
int w_, h_;
float uv_offset_[2];
Vector<uint32_t> pixel_data_;
ZSpan zspan_;
uint32_t value_to_store_;
char *mask_;
MPoly const *mpoly_;
MLoop const *mloop_;
MLoopUV const *mloopuv_;
int totpoly_;
int totloop_;
int totedge_;
public:
TextureMarginMap(size_t w,
size_t h,
const float uv_offset[2],
MPoly const *mpoly,
MLoop const *mloop,
MLoopUV const *mloopuv,
int totpoly,
int totloop,
int totedge)
: w_(w),
h_(h),
mpoly_(mpoly),
mloop_(mloop),
mloopuv_(mloopuv),
totpoly_(totpoly),
totloop_(totloop),
totedge_(totedge)
{
copy_v2_v2(uv_offset_, uv_offset);
pixel_data_.resize(w_ * h_, 0xFFFFFFFF);
zbuf_alloc_span(&zspan_, w_, h_);
build_tables();
}
~TextureMarginMap()
{
zbuf_free_span(&zspan_);
}
inline void set_pixel(int x, int y, uint32_t value)
{
BLI_assert(x < w_);
BLI_assert(x >= 0);
pixel_data_[y * w_ + x] = value;
}
inline uint32_t get_pixel(int x, int y) const
{
if (x < 0 || y < 0 || x >= w_ || y >= h_) {
return 0xFFFFFFFF;
}
return pixel_data_[y * w_ + x];
}
void rasterize_tri(float *v1, float *v2, float *v3, uint32_t value, char *mask)
{
/* NOTE: This is not thread safe, because the value to be written by the rasterizer is
* a class member. If this is ever made multi-threaded each thread needs to get its own. */
value_to_store_ = value;
mask_ = mask;
zspan_scanconvert(
&zspan_, this, &(v1[0]), &(v2[0]), &(v3[0]), TextureMarginMap::zscan_store_pixel);
}
static void zscan_store_pixel(
void *map, int x, int y, [[maybe_unused]] float u, [[maybe_unused]] float v)
{
/* NOTE: Not thread safe, see comment above. */
TextureMarginMap *m = static_cast<TextureMarginMap *>(map);
m->set_pixel(x, y, m->value_to_store_);
if (m->mask_) {
m->mask_[y * m->w_ + x] = 1;
}
}
/* The map contains 2 kinds of pixels: DijkstraPixels and polygon indices. The top bit determines
* what kind it is. With the top bit set, it is a 'dijkstra' pixel. The bottom 4 bits encode the
* direction of the shortest path and the remaining 27 bits are used to store the distance. If
* the top bit is not set, the rest of the bits is used to store the polygon index.
*/
#define PackDijkstraPixel(dist, dir) (0x80000000 + ((dist) << 4) + (dir))
#define DijkstraPixelGetDistance(dp) (((dp) ^ 0x80000000) >> 4)
#define DijkstraPixelGetDirection(dp) ((dp)&0xF)
#define IsDijkstraPixel(dp) ((dp)&0x80000000)
#define DijkstraPixelIsUnset(dp) ((dp) == 0xFFFFFFFF)
/**
* Use dijkstra's algorithm to 'grow' a border around the polygons marked in the map.
* For each pixel mark which direction is the shortest way to a polygon.
*/
void grow_dijkstra(int margin)
{
class DijkstraActivePixel {
public:
DijkstraActivePixel(int dist, int _x, int _y) : distance(dist), x(_x), y(_y)
{
}
int distance;
int x, y;
};
auto cmp_dijkstrapixel_fun = [](DijkstraActivePixel const &a1, DijkstraActivePixel const &a2) {
return a1.distance > a2.distance;
};
Vector<DijkstraActivePixel> active_pixels;
for (int y = 0; y < h_; y++) {
for (int x = 0; x < w_; x++) {
if (DijkstraPixelIsUnset(get_pixel(x, y))) {
for (int i = 0; i < 8; i++) {
int xx = x - directions[i][0];
int yy = y - directions[i][1];
if (xx >= 0 && xx < w_ && yy >= 0 && yy < w_ && !IsDijkstraPixel(get_pixel(xx, yy))) {
set_pixel(x, y, PackDijkstraPixel(distances[i], i));
active_pixels.append(DijkstraActivePixel(distances[i], x, y));
break;
}
}
}
}
}
/* Not strictly needed because at this point it already is a heap. */
#if 0
std::make_heap(active_pixels.begin(), active_pixels.end(), cmp_dijkstrapixel_fun);
#endif
while (active_pixels.size()) {
std::pop_heap(active_pixels.begin(), active_pixels.end(), cmp_dijkstrapixel_fun);
DijkstraActivePixel p = active_pixels.pop_last();
int dist = p.distance;
if (dist < 2 * (margin + 1)) {
for (int i = 0; i < 8; i++) {
int x = p.x + directions[i][0];
int y = p.y + directions[i][1];
if (x >= 0 && x < w_ && y >= 0 && y < h_) {
uint32_t dp = get_pixel(x, y);
if (IsDijkstraPixel(dp) && (DijkstraPixelGetDistance(dp) > dist + distances[i])) {
BLI_assert(DijkstraPixelGetDirection(dp) != i);
set_pixel(x, y, PackDijkstraPixel(dist + distances[i], i));
active_pixels.append(DijkstraActivePixel(dist + distances[i], x, y));
std::push_heap(active_pixels.begin(), active_pixels.end(), cmp_dijkstrapixel_fun);
}
}
}
}
}
}
/**
* Walk over the map and for margin pixels follow the direction stored in the bottom 3
* bits back to the polygon.
* Then look up the pixel from the next polygon.
*/
void lookup_pixels(ImBuf *ibuf, char *mask, int maxPolygonSteps)
{
for (int y = 0; y < h_; y++) {
for (int x = 0; x < w_; x++) {
uint32_t dp = get_pixel(x, y);
if (IsDijkstraPixel(dp) && !DijkstraPixelIsUnset(dp)) {
int dist = DijkstraPixelGetDistance(dp);
int direction = DijkstraPixelGetDirection(dp);
int xx = x;
int yy = y;
/* Follow the dijkstra directions to find the polygon this margin pixels belongs to. */
while (dist > 0) {
xx -= directions[direction][0];
yy -= directions[direction][1];
dp = get_pixel(xx, yy);
dist -= distances[direction];
BLI_assert(!dist || (dist == DijkstraPixelGetDistance(dp)));
direction = DijkstraPixelGetDirection(dp);
}
uint32_t poly = get_pixel(xx, yy);
BLI_assert(!IsDijkstraPixel(poly));
float destX, destY;
int other_poly;
bool found_pixel_in_polygon = false;
if (lookup_pixel_polygon_neighbourhood(x, y, &poly, &destX, &destY, &other_poly)) {
for (int i = 0; i < maxPolygonSteps; i++) {
/* Force to pixel grid. */
int nx = (int)round(destX);
int ny = (int)round(destY);
uint32_t polygon_from_map = get_pixel(nx, ny);
if (other_poly == polygon_from_map) {
found_pixel_in_polygon = true;
break;
}
float dist_to_edge;
/* Look up again, but starting from the polygon we were expected to land in. */
if (!lookup_pixel(nx, ny, other_poly, &destX, &destY, &other_poly, &dist_to_edge)) {
found_pixel_in_polygon = false;
break;
}
}
if (found_pixel_in_polygon) {
bilinear_interpolation(ibuf, ibuf, destX, destY, x, y);
/* Add our new pixels to the assigned pixel map. */
mask[y * w_ + x] = 1;
}
}
}
else if (DijkstraPixelIsUnset(dp) || !IsDijkstraPixel(dp)) {
/* These are not margin pixels, make sure the extend filter which is run after this step
* leaves them alone.
*/
mask[y * w_ + x] = 1;
}
}
}
}
private:
float2 uv_to_xy(MLoopUV const &mloopuv) const
{
float2 ret;
ret.x = (((mloopuv.uv[0] - uv_offset_[0]) * w_) - (0.5f + 0.001f));
ret.y = (((mloopuv.uv[1] - uv_offset_[1]) * h_) - (0.5f + 0.001f));
return ret;
}
void build_tables()
{
loop_to_poly_map_.resize(totloop_);
for (int i = 0; i < totpoly_; i++) {
for (int j = 0; j < mpoly_[i].totloop; j++) {
int l = j + mpoly_[i].loopstart;
loop_to_poly_map_[l] = i;
}
}
loop_adjacency_map_.resize(totloop_, -1);
Vector<int> tmpmap;
tmpmap.resize(totedge_, -1);
for (size_t i = 0; i < totloop_; i++) {
int edge = mloop_[i].e;
if (tmpmap[edge] == -1) {
loop_adjacency_map_[i] = -1;
tmpmap[edge] = i;
}
else {
BLI_assert(tmpmap[edge] >= 0);
loop_adjacency_map_[i] = tmpmap[edge];
loop_adjacency_map_[tmpmap[edge]] = i;
}
}
}
/**
* Call lookup_pixel for the start_poly. If that fails, try the adjacent polygons as well.
* Because the Dijkstra is not very exact in determining which polygon is the closest, the
* polygon we need can be the one next to the one the Dijkstra map provides. To prevent missing
* pixels also check the neighboring polygons.
*/
bool lookup_pixel_polygon_neighbourhood(
float x, float y, uint32_t *r_start_poly, float *r_destx, float *r_desty, int *r_other_poly)
{
float found_dist;
if (lookup_pixel(x, y, *r_start_poly, r_destx, r_desty, r_other_poly, &found_dist)) {
return true;
}
int loopstart = mpoly_[*r_start_poly].loopstart;
int totloop = mpoly_[*r_start_poly].totloop;
float destx, desty;
int foundpoly;
float mindist = -1.0f;
/* Loop over all adjacent polygons and determine which edge is closest.
* This could be optimized by only inspecting neighbors which are on the edge of an island.
* But it seems fast enough for now and that would add a lot of complexity. */
for (int i = 0; i < totloop; i++) {
int otherloop = loop_adjacency_map_[i + loopstart];
if (otherloop < 0) {
continue;
}
uint32_t poly = loop_to_poly_map_[otherloop];
if (lookup_pixel(x, y, poly, &destx, &desty, &foundpoly, &found_dist)) {
if (mindist < 0.f || found_dist < mindist) {
mindist = found_dist;
*r_other_poly = foundpoly;
*r_destx = destx;
*r_desty = desty;
*r_start_poly = poly;
}
}
}
return mindist >= 0.0f;
}
/**
* Find which edge of the src_poly is closest to x,y. Look up its adjacent UV-edge and polygon.
* Then return the location of the equivalent pixel in the other polygon.
* Returns true if a new pixel location was found, false if it wasn't, which can happen if the
* margin pixel is on a corner, or the UV-edge doesn't have an adjacent polygon.
*/
bool lookup_pixel(float x,
float y,
int src_poly,
float *r_destx,
float *r_desty,
int *r_other_poly,
float *r_dist_to_edge)
{
float2 point(x, y);
*r_destx = *r_desty = 0;
int found_edge = -1;
float found_dist = -1;
float found_t = 0;
/* Find the closest edge on which the point x,y can be projected.
*/
for (size_t i = 0; i < mpoly_[src_poly].totloop; i++) {
int l1 = mpoly_[src_poly].loopstart + i;
int l2 = l1 + 1;
if (l2 >= mpoly_[src_poly].loopstart + mpoly_[src_poly].totloop) {
l2 = mpoly_[src_poly].loopstart;
}
/* edge points */
float2 edgepoint1 = uv_to_xy(mloopuv_[l1]);
float2 edgepoint2 = uv_to_xy(mloopuv_[l2]);
/* Vector AB is the vector from the first edge point to the second edge point.
* Vector AP is the vector from the first edge point to our point under investigation. */
float2 ab = edgepoint2 - edgepoint1;
float2 ap = point - edgepoint1;
/* Project ap onto ab. */
float dotv = math::dot(ab, ap);
float ablensq = math::length_squared(ab);
float t = dotv / ablensq;
if (t >= 0.0 && t <= 1.0) {
/* Find the point on the edge closest to P */
float2 reflect_point = edgepoint1 + (t * ab);
/* This is the vector to P, so 90 degrees out from the edge. */
float2 reflect_vec = reflect_point - point;
float reflectLen = sqrt(reflect_vec[0] * reflect_vec[0] + reflect_vec[1] * reflect_vec[1]);
float cross = ab[0] * reflect_vec[1] - ab[1] * reflect_vec[0];
/* Only if P is on the outside of the edge, which means the cross product is positive,
* we consider this edge.
*/
bool valid = (cross > 0.0);
if (valid && (found_dist < 0 || reflectLen < found_dist)) {
/* Stother_ab the info of the closest edge so far. */
found_dist = reflectLen;
found_t = t;
found_edge = i + mpoly_[src_poly].loopstart;
}
}
}
if (found_edge < 0) {
return false;
}
*r_dist_to_edge = found_dist;
/* Get the 'other' edge. I.E. the UV edge from the neighbor polygon. */
int other_edge = loop_adjacency_map_[found_edge];
if (other_edge < 0) {
return false;
}
int dst_poly = loop_to_poly_map_[other_edge];
if (r_other_poly) {
*r_other_poly = dst_poly;
}
int other_edge2 = other_edge + 1;
if (other_edge2 >= mpoly_[dst_poly].loopstart + mpoly_[dst_poly].totloop) {
other_edge2 = mpoly_[dst_poly].loopstart;
}
float2 other_edgepoint1 = uv_to_xy(mloopuv_[other_edge]);
float2 other_edgepoint2 = uv_to_xy(mloopuv_[other_edge2]);
/* Calculate the vector from the order edges last point to its first point. */
float2 other_ab = other_edgepoint1 - other_edgepoint2;
float2 other_reflect_point = other_edgepoint2 + (found_t * other_ab);
float2 perpendicular_other_ab;
perpendicular_other_ab.x = other_ab.y;
perpendicular_other_ab.y = -other_ab.x;
/* The new point is dound_dist distance from other_reflect_point at a 90 degree angle to
* other_ab */
float2 new_point = other_reflect_point + (found_dist / math::length(perpendicular_other_ab)) *
perpendicular_other_ab;
*r_destx = new_point.x;
*r_desty = new_point.y;
return true;
}
}; // class TextureMarginMap
const int TextureMarginMap::directions[8][2] = {
{-1, 0}, {-1, -1}, {0, -1}, {1, -1}, {1, 0}, {1, 1}, {0, 1}, {-1, 1}};
const int TextureMarginMap::distances[8] = {2, 3, 2, 3, 2, 3, 2, 3};
static void generate_margin(ImBuf *ibuf,
char *mask,
const int margin,
const Mesh *me,
DerivedMesh *dm,
char const *uv_layer,
const float uv_offset[2])
{
MPoly *mpoly;
MLoop *mloop;
const MLoopUV *mloopuv;
int totpoly, totloop, totedge;
int tottri;
const MLoopTri *looptri;
MLoopTri *looptri_mem = nullptr;
if (me) {
BLI_assert(dm == nullptr);
totpoly = me->totpoly;
totloop = me->totloop;
totedge = me->totedge;
mpoly = me->mpoly;
mloop = me->mloop;
if ((uv_layer == nullptr) || (uv_layer[0] == '\0')) {
mloopuv = static_cast<const MLoopUV *>(CustomData_get_layer(&me->ldata, CD_MLOOPUV));
}
else {
int uv_id = CustomData_get_named_layer(&me->ldata, CD_MLOOPUV, uv_layer);
mloopuv = static_cast<const MLoopUV *>(
CustomData_get_layer_n(&me->ldata, CD_MLOOPUV, uv_id));
}
tottri = poly_to_tri_count(me->totpoly, me->totloop);
looptri_mem = static_cast<MLoopTri *>(MEM_mallocN(sizeof(*looptri) * tottri, __func__));
BKE_mesh_recalc_looptri(
me->mloop, me->mpoly, me->mvert, me->totloop, me->totpoly, looptri_mem);
looptri = looptri_mem;
}
else {
BLI_assert(dm != nullptr);
BLI_assert(me == nullptr);
totpoly = dm->getNumPolys(dm);
totedge = dm->getNumEdges(dm);
totloop = dm->getNumLoops(dm);
mpoly = dm->getPolyArray(dm);
mloop = dm->getLoopArray(dm);
mloopuv = (MLoopUV const *)dm->getLoopDataArray(dm, CD_MLOOPUV);
looptri = dm->getLoopTriArray(dm);
tottri = dm->getNumLoopTri(dm);
}
TextureMarginMap map(
ibuf->x, ibuf->y, uv_offset, mpoly, mloop, mloopuv, totpoly, totloop, totedge);
bool draw_new_mask = false;
/* Now the map contains 3 sorts of values: 0xFFFFFFFF for empty pixels, `0x80000000 + polyindex`
* for margin pixels, just `polyindex` for poly pixels. */
if (mask) {
mask = (char *)MEM_dupallocN(mask);
}
else {
mask = (char *)MEM_callocN(sizeof(char) * ibuf->x * ibuf->y, __func__);
draw_new_mask = true;
}
for (int i = 0; i < tottri; i++) {
const MLoopTri *lt = &looptri[i];
float vec[3][2];
for (int a = 0; a < 3; a++) {
const float *uv = mloopuv[lt->tri[a]].uv;
/* NOTE(campbell): workaround for pixel aligned UVs which are common and can screw up our
* intersection tests where a pixel gets in between 2 faces or the middle of a quad,
* camera aligned quads also have this problem but they are less common.
* Add a small offset to the UVs, fixes bug T18685. */
vec[a][0] = (uv[0] - uv_offset[0]) * (float)ibuf->x - (0.5f + 0.001f);
vec[a][1] = (uv[1] - uv_offset[1]) * (float)ibuf->y - (0.5f + 0.002f);
}
/* NOTE: we need the top bit for the dijkstra distance map. */
BLI_assert(lt->poly < 0x80000000);
map.rasterize_tri(vec[0], vec[1], vec[2], lt->poly, draw_new_mask ? mask : nullptr);
}
char *tmpmask = (char *)MEM_dupallocN(mask);
/* Extend (with averaging) by 2 pixels. Those will be overwritten, but it
* helps linear interpolations on the edges of polygons. */
IMB_filter_extend(ibuf, tmpmask, 2);
MEM_freeN(tmpmask);
map.grow_dijkstra(margin);
/* Looking further than 3 polygons away leads to so much cumulative rounding
* that it isn't worth it. So hard-code it to 3. */
map.lookup_pixels(ibuf, mask, 3);
/* Use the extend filter to fill in the missing pixels at the corners, not strictly correct, but
* the visual difference seems very minimal. This also catches pixels we missed because of very
* narrow polygons.
*/
IMB_filter_extend(ibuf, mask, margin);
MEM_freeN(mask);
if (looptri_mem) {
MEM_freeN(looptri_mem);
}
}
} // namespace blender::render::texturemargin
void RE_generate_texturemargin_adjacentfaces(ImBuf *ibuf,
char *mask,
const int margin,
const Mesh *me,
char const *uv_layer,
const float uv_offset[2])
{
blender::render::texturemargin::generate_margin(
ibuf, mask, margin, me, nullptr, uv_layer, uv_offset);
}
void RE_generate_texturemargin_adjacentfaces_dm(
ImBuf *ibuf, char *mask, const int margin, DerivedMesh *dm, const float uv_offset[2])
{
blender::render::texturemargin::generate_margin(
ibuf, mask, margin, nullptr, dm, nullptr, uv_offset);
}