diff options
Diffstat (limited to 'thirdparty/thekla_atlas/nvmesh/param/AtlasPacker.cpp')
-rw-r--r-- | thirdparty/thekla_atlas/nvmesh/param/AtlasPacker.cpp | 1387 |
1 files changed, 1387 insertions, 0 deletions
diff --git a/thirdparty/thekla_atlas/nvmesh/param/AtlasPacker.cpp b/thirdparty/thekla_atlas/nvmesh/param/AtlasPacker.cpp new file mode 100644 index 0000000000..5ce452cb9e --- /dev/null +++ b/thirdparty/thekla_atlas/nvmesh/param/AtlasPacker.cpp @@ -0,0 +1,1387 @@ +// This code is in the public domain -- castano@gmail.com + +#include "nvmesh.h" // pch + +#include "AtlasPacker.h" +#include "nvmesh/halfedge/Vertex.h" +#include "nvmesh/halfedge/Face.h" +#include "nvmesh/param/Atlas.h" +#include "nvmesh/param/Util.h" +#include "nvmesh/raster/Raster.h" + +#include "nvmath/Vector.inl" +#include "nvmath/ConvexHull.h" +#include "nvmath/Color.h" +#include "nvmath/ftoi.h" + +#include "nvcore/StrLib.h" // debug +#include "nvcore/StdStream.h" // fileOpen + +#include <float.h> // FLT_MAX +#include <limits.h> // UINT_MAX + +using namespace nv; + +#define DEBUG_OUTPUT 0 + +#if DEBUG_OUTPUT + +#include "nvimage/ImageIO.h" + +namespace +{ + const uint TGA_TYPE_GREY = 3; + const uint TGA_TYPE_RGB = 2; + const uint TGA_ORIGIN_UPPER = 0x20; + +#pragma pack(push, 1) + struct TgaHeader { + uint8 id_length; + uint8 colormap_type; + uint8 image_type; + uint16 colormap_index; + uint16 colormap_length; + uint8 colormap_size; + uint16 x_origin; + uint16 y_origin; + uint16 width; + uint16 height; + uint8 pixel_size; + uint8 flags; + + enum { Size = 18 }; //const static int SIZE = 18; + }; +#pragma pack(pop) + + static void outputDebugBitmap(const char * fileName, const BitMap & bitmap, int w, int h) + { + FILE * fp = fileOpen(fileName, "wb"); + if (fp == NULL) return; + + nvStaticCheck(sizeof(TgaHeader) == TgaHeader::Size); + TgaHeader tga; + tga.id_length = 0; + tga.colormap_type = 0; + tga.image_type = TGA_TYPE_GREY; + + tga.colormap_index = 0; + tga.colormap_length = 0; + tga.colormap_size = 0; + + tga.x_origin = 0; + tga.y_origin = 0; + tga.width = w; + tga.height = h; + tga.pixel_size = 8; + tga.flags = TGA_ORIGIN_UPPER; + + fwrite(&tga, sizeof(TgaHeader), 1, fp); + + for (int j = 0; j < h; j++) { + for (int i = 0; i < w; i++) { + uint8 color = bitmap.bitAt(i, j) ? 0xFF : 0x0; + fwrite(&color, 1, 1, fp); + } + } + + fclose(fp); + } + + static void outputDebugImage(const char * fileName, const Image & bitmap, int w, int h) + { + FILE * fp = fileOpen(fileName, "wb"); + if (fp == NULL) return; + + nvStaticCheck(sizeof(TgaHeader) == TgaHeader::Size); + TgaHeader tga; + tga.id_length = 0; + tga.colormap_type = 0; + tga.image_type = TGA_TYPE_RGB; + + tga.colormap_index = 0; + tga.colormap_length = 0; + tga.colormap_size = 0; + + tga.x_origin = 0; + tga.y_origin = 0; + tga.width = w; + tga.height = h; + tga.pixel_size = 24; + tga.flags = TGA_ORIGIN_UPPER; + + fwrite(&tga, sizeof(TgaHeader), 1, fp); + + for (int j = 0; j < h; j++) { + for (int i = 0; i < w; i++) { + Color32 color = bitmap.pixel(i, j); + fwrite(&color.r, 1, 1, fp); + fwrite(&color.g, 1, 1, fp); + fwrite(&color.b, 1, 1, fp); + } + } + + fclose(fp); + } +} + +#endif // DEBUG_OUTPUT + +inline int align(int x, int a) { + //return a * ((x + a - 1) / a); + //return (x + a - 1) & -a; + return (x + a - 1) & ~(a - 1); +} + +inline bool isAligned(int x, int a) { + return (x & (a - 1)) == 0; +} + + + +AtlasPacker::AtlasPacker(Atlas * atlas) : m_atlas(atlas), m_bitmap(256, 256) +{ + m_width = 0; + m_height = 0; + + m_debug_bitmap.allocate(256, 256); + m_debug_bitmap.fill(Color32(0,0,0,0)); +} + +AtlasPacker::~AtlasPacker() +{ +} + +// This should compute convex hull and use rotating calipers to find the best box. Currently it uses a brute force method. +static bool computeBoundingBox(Chart * chart, Vector2 * majorAxis, Vector2 * minorAxis, Vector2 * minCorner, Vector2 * maxCorner) +{ + // Compute list of boundary points. + Array<Vector2> points(16); + + HalfEdge::Mesh * mesh = chart->chartMesh(); + const uint vertexCount = mesh->vertexCount(); + + for (uint i = 0; i < vertexCount; i++) { + HalfEdge::Vertex * vertex = mesh->vertexAt(i); + if (vertex->isBoundary()) { + points.append(vertex->tex); + } + } + + // This is not valid anymore. The chart mesh may have multiple boundaries! + /*const HalfEdge::Vertex * vertex = findBoundaryVertex(chart->chartMesh()); + + // Traverse boundary. + const HalfEdge::Edge * const firstEdge = vertex->edge(); + const HalfEdge::Edge * edge = firstEdge; + do { + vertex = edge->vertex(); + + nvDebugCheck (vertex->isBoundary()); + points.append(vertex->tex); + + edge = edge->next(); + } while (edge != firstEdge);*/ + +#if 1 + Array<Vector2> hull; + if (points.size()==0) { + return false; + } + + convexHull(points, hull, 0.00001f); + + // @@ Ideally I should use rotating calipers to find the best box. Using brute force for now. + + float best_area = FLT_MAX; + Vector2 best_min; + Vector2 best_max; + Vector2 best_axis; + + const uint hullCount = hull.count(); + for (uint i = 0, j = hullCount-1; i < hullCount; j = i, i++) { + + if (equal(hull[i], hull[j])) { + continue; + } + + Vector2 axis = normalize(hull[i] - hull[j], 0.0f); + nvDebugCheck(isFinite(axis)); + + // Compute bounding box. + Vector2 box_min(FLT_MAX, FLT_MAX); + Vector2 box_max(-FLT_MAX, -FLT_MAX); + + for (uint v = 0; v < hullCount; v++) { + + Vector2 point = hull[v]; + + float x = dot(axis, point); + if (x < box_min.x) box_min.x = x; + if (x > box_max.x) box_max.x = x; + + float y = dot(Vector2(-axis.y, axis.x), point); + if (y < box_min.y) box_min.y = y; + if (y > box_max.y) box_max.y = y; + } + + // Compute box area. + float area = (box_max.x - box_min.x) * (box_max.y - box_min.y); + + if (area < best_area) { + best_area = area; + best_min = box_min; + best_max = box_max; + best_axis = axis; + } + } + + // Make sure the box contains all the input points since the convex hull is not 100% accurate. + /*const uint pointCount = points.count(); + for (uint v = 0; v < pointCount; v++) { + + Vector2 point = points[v]; + + float x = dot(best_axis, point); + if (x < best_min.x) best_min.x = x; + + float y = dot(Vector2(-best_axis.y, best_axis.x), point); + if (y < best_min.y) best_min.y = y; + }*/ + + // Consider all points, not only boundary points, in case the input chart is malformed. + for (uint i = 0; i < vertexCount; i++) { + HalfEdge::Vertex * vertex = mesh->vertexAt(i); + Vector2 point = vertex->tex; + + float x = dot(best_axis, point); + if (x < best_min.x) best_min.x = x; + if (x > best_max.x) best_max.x = x; + + float y = dot(Vector2(-best_axis.y, best_axis.x), point); + if (y < best_min.y) best_min.y = y; + if (y > best_max.y) best_max.y = y; + } + + *majorAxis = best_axis; + *minorAxis = Vector2(-best_axis.y, best_axis.x); + *minCorner = best_min; + *maxCorner = best_max; + +#else + // Approximate implementation: try 16 different directions and keep the best. + + const uint N = 16; + Vector2 axis[N]; + + float minAngle = 0; + float maxAngle = PI / 2; + + int best; + Vector2 mins[N]; + Vector2 maxs[N]; + + const int iterationCount = 1; + for (int j = 0; j < iterationCount; j++) + { + // Init predefined directions. + for (int i = 0; i < N; i++) + { + float angle = lerp(minAngle, maxAngle, float(i)/N); + axis[i].set(cosf(angle), sinf(angle)); + } + + // Compute box for each direction. + for (int i = 0; i < N; i++) + { + mins[i].set(FLT_MAX, FLT_MAX); + maxs[i].set(-FLT_MAX, -FLT_MAX); + } + + for (uint p = 0; p < points.count(); p++) + { + Vector2 point = points[p]; + + for (int i = 0; i < N; i++) + { + float x = dot(axis[i], point); + if (x < mins[i].x) mins[i].x = x; + if (x > maxs[i].x) maxs[i].x = x; + + float y = dot(Vector2(-axis[i].y, axis[i].x), point); + if (y < mins[i].y) mins[i].y = y; + if (y > maxs[i].y) maxs[i].y = y; + } + } + + // Find box with minimum area. + best = -1; + int second_best = -1; + float best_area = FLT_MAX; + float second_best_area = FLT_MAX; + + for (int i = 0; i < N; i++) + { + float area = (maxs[i].x - mins[i].x) * (maxs[i].y - mins[i].y); + + if (area < best_area) + { + second_best_area = best_area; + second_best = best; + + best_area = area; + best = i; + } + else if (area < second_best_area) + { + second_best_area = area; + second_best = i; + } + } + nvDebugCheck(best != -1); + nvDebugCheck(second_best != -1); + nvDebugCheck(best != second_best); + + if (j != iterationCount-1) + { + // Handle wrap-around during the first iteration. + if (j == 0) { + if (best == 0 && second_best == N-1) best = N; + if (best == N-1 && second_best == 0) second_best = N; + } + + if (best < second_best) swap(best, second_best); + + // Update angles. + float deltaAngle = (maxAngle - minAngle) / N; + maxAngle = minAngle + (best - 0.5f) * deltaAngle; + minAngle = minAngle + (second_best + 0.5f) * deltaAngle; + } + } + + // Compute major and minor axis, and origin. + *majorAxis = axis[best]; + *minorAxis = Vector2(-axis[best].y, axis[best].x); + *origin = mins[best]; + + // @@ If the parameterization is invalid, we could have an interior vertex outside the boundary. + // @@ In that case the returned bounding box would be incorrect. Compute updated bounds here. + /*for (uint p = 0; p < points.count(); p++) + { + Vector2 point = points[p]; + + for (int i = 0; i < N; i++) + { + float x = dot(*majorAxis, point); + float y = dot(*minorAxis, point); + } + }*/ +#endif + + return true; +} + + +void AtlasPacker::packCharts(int quality, float texelsPerUnit, bool blockAligned, bool conservative) +{ + const uint chartCount = m_atlas->chartCount(); + if (chartCount == 0) return; + + Array<float> chartOrderArray; + chartOrderArray.resize(chartCount); + + Array<Vector2> chartExtents; + chartExtents.resize(chartCount); + + float meshArea = 0; + for (uint c = 0; c < chartCount; c++) + { + Chart * chart = m_atlas->chartAt(c); + + if (!chart->isVertexMapped() && !chart->isDisk()) { + chartOrderArray[c] = 0; + + // Skip non-disks. + continue; + } + + Vector2 extents(0.0f); + + if (chart->isVertexMapped()) { + // Let's assume vertex maps are arranged in a rectangle. + //HalfEdge::Mesh * mesh = chart->chartMesh(); + + // Arrange vertices in a rectangle. + extents.x = float(chart->vertexMapWidth); + extents.y = float(chart->vertexMapHeight); + } + else { + // Compute surface area to sort charts. + float chartArea = chart->computeSurfaceArea(); + meshArea += chartArea; + //chartOrderArray[c] = chartArea; + + // Compute chart scale + float parametricArea = fabs(chart->computeParametricArea()); // @@ There doesn't seem to be anything preventing parametric area to be negative. + if (parametricArea < NV_EPSILON) { + // When the parametric area is too small we use a rough approximation to prevent divisions by very small numbers. + Vector2 bounds = chart->computeParametricBounds(); + parametricArea = bounds.x * bounds.y; + } + float scale = (chartArea / parametricArea) * texelsPerUnit; + if (parametricArea == 0) // < NV_EPSILON) + { + scale = 0; + } + nvCheck(isFinite(scale)); + + // Compute bounding box of chart. + Vector2 majorAxis, minorAxis, origin, end; + if (!computeBoundingBox(chart, &majorAxis, &minorAxis, &origin, &end)) { + m_atlas->setFailed(); + return; + } + + nvCheck(isFinite(majorAxis) && isFinite(minorAxis) && isFinite(origin)); + + // Sort charts by perimeter. @@ This is sometimes producing somewhat unexpected results. Is this right? + //chartOrderArray[c] = ((end.x - origin.x) + (end.y - origin.y)) * scale; + + // Translate, rotate and scale vertices. Compute extents. + HalfEdge::Mesh * mesh = chart->chartMesh(); + const uint vertexCount = mesh->vertexCount(); + for (uint i = 0; i < vertexCount; i++) + { + HalfEdge::Vertex * vertex = mesh->vertexAt(i); + + //Vector2 t = vertex->tex - origin; + Vector2 tmp; + tmp.x = dot(vertex->tex, majorAxis); + tmp.y = dot(vertex->tex, minorAxis); + tmp -= origin; + tmp *= scale; + if (tmp.x < 0 || tmp.y < 0) { + nvDebug("tmp: %f %f\n", tmp.x, tmp.y); + nvDebug("scale: %f\n", scale); + nvDebug("origin: %f %f\n", origin.x, origin.y); + nvDebug("majorAxis: %f %f\n", majorAxis.x, majorAxis.y); + nvDebug("minorAxis: %f %f\n", minorAxis.x, minorAxis.y); + nvDebugBreak(); + } + //nvCheck(tmp.x >= 0 && tmp.y >= 0); + + vertex->tex = tmp; + + nvCheck(isFinite(vertex->tex.x) && isFinite(vertex->tex.y)); + + extents = max(extents, tmp); + } + nvDebugCheck(extents.x >= 0 && extents.y >= 0); + + // Limit chart size. + if (extents.x > 1024 || extents.y > 1024) { + float limit = max(extents.x, extents.y); + + scale = 1024 / (limit + 1); + + for (uint i = 0; i < vertexCount; i++) + { + HalfEdge::Vertex * vertex = mesh->vertexAt(i); + vertex->tex *= scale; + } + + extents *= scale; + + nvDebugCheck(extents.x <= 1024 && extents.y <= 1024); + } + + + // Scale the charts to use the entire texel area available. So, if the width is 0.1 we could scale it to 1 without increasing the lightmap usage and making a better + // use of it. In many cases this also improves the look of the seams, since vertices on the chart boundaries have more chances of being aligned with the texel centers. + + float scale_x = 1.0f; + float scale_y = 1.0f; + + float divide_x = 1.0f; + float divide_y = 1.0f; + + if (extents.x > 0) { + int cw = ftoi_ceil(extents.x); + + if (blockAligned) { + // Align all chart extents to 4x4 blocks, but taking padding into account. + if (conservative) { + cw = align(cw + 2, 4) - 2; + } + else { + cw = align(cw + 1, 4) - 1; + } + } + + scale_x = (float(cw) - NV_EPSILON); + divide_x = extents.x; + extents.x = float(cw); + } + + if (extents.y > 0) { + int ch = ftoi_ceil(extents.y); + + if (blockAligned) { + // Align all chart extents to 4x4 blocks, but taking padding into account. + if (conservative) { + ch = align(ch + 2, 4) - 2; + } + else { + ch = align(ch + 1, 4) - 1; + } + } + + scale_y = (float(ch) - NV_EPSILON); + divide_y = extents.y; + extents.y = float(ch); + } + + for (uint v = 0; v < vertexCount; v++) { + HalfEdge::Vertex * vertex = mesh->vertexAt(v); + + vertex->tex.x /= divide_x; + vertex->tex.y /= divide_y; + vertex->tex.x *= scale_x; + vertex->tex.y *= scale_y; + + nvCheck(isFinite(vertex->tex.x) && isFinite(vertex->tex.y)); + } + } + + chartExtents[c] = extents; + + // Sort charts by perimeter. + chartOrderArray[c] = extents.x + extents.y; + } + + // @@ We can try to improve compression of small charts by sorting them by proximity like we do with vertex samples. + // @@ How to do that? One idea: compute chart centroid, insert into grid, compute morton index of the cell, sort based on morton index. + // @@ We would sort by morton index, first, then quantize the chart sizes, so that all small charts have the same size, and sort by size preserving the morton order. + + //nvDebug("Sorting charts.\n"); + + // Sort charts by area. + m_radix.sort(chartOrderArray); + const uint32 * ranks = m_radix.ranks(); + + // Estimate size of the map based on the mesh surface area and given texel scale. + float texelCount = meshArea * square(texelsPerUnit) / 0.75f; // Assume 75% utilization. + if (texelCount < 1) texelCount = 1; + uint approximateExtent = nextPowerOfTwo(uint(sqrtf(texelCount))); + + //nvDebug("Init bitmap.\n"); + + // @@ Pack all charts smaller than a texel into a compact rectangle. + // @@ Start considering only 1x1 charts. Extend to 1xn charts later. + + /*for (uint i = 0; i < chartCount; i++) + { + uint c = ranks[chartCount - i - 1]; // largest chart first + + Chart * chart = m_atlas->chartAt(c); + + if (!chart->isDisk()) continue; + + if (iceil(chartExtents[c].x) == 1 && iceil(chartExtents[c].x) == 1) { + // @@ Add to + } + }*/ + + + + // Init bit map. + m_bitmap.clearAll(); + if (approximateExtent > m_bitmap.width()) { + m_bitmap.resize(approximateExtent, approximateExtent, false); + m_debug_bitmap.resize(approximateExtent, approximateExtent); + m_debug_bitmap.fill(Color32(0,0,0,0)); + } + + + int w = 0; + int h = 0; + +#if 1 + // Add sorted charts to bitmap. + for (uint i = 0; i < chartCount; i++) + { + uint c = ranks[chartCount - i - 1]; // largest chart first + + Chart * chart = m_atlas->chartAt(c); + + if (!chart->isVertexMapped() && !chart->isDisk()) continue; + + //float scale_x = 1; + //float scale_y = 1; + + BitMap chart_bitmap; + + if (chart->isVertexMapped()) { + // Init all bits to 1. + chart_bitmap.resize(ftoi_ceil(chartExtents[c].x), ftoi_ceil(chartExtents[c].y), /*initValue=*/true); + + // @@ Another alternative would be to try to map each vertex to a different texel trying to fill all the available unused texels. + } + else { + // @@ Add special cases for dot and line charts. @@ Lightmap rasterizer also needs to handle these special cases. + // @@ We could also have a special case for chart quads. If the quad surface <= 4 texels, align vertices with texel centers and do not add padding. May be very useful for foliage. + + // @@ In general we could reduce the padding of all charts by one texel by using a rasterizer that takes into account the 2-texel footprint of the tent bilinear filter. For example, + // if we have a chart that is less than 1 texel wide currently we add one texel to the left and one texel to the right creating a 3-texel-wide bitmap. However, if we know that the + // chart is only 1 texel wide we could align it so that it only touches the footprint of two texels: + + // | | <- Touches texels 0, 1 and 2. + // | | <- Only touches texels 0 and 1. + // \ \ / \ / / + // \ X X / + // \ / \ / \ / + // V V V + // 0 1 2 + + if (conservative) { + // Init all bits to 0. + chart_bitmap.resize(ftoi_ceil(chartExtents[c].x) + 2, ftoi_ceil(chartExtents[c].y) + 2, /*initValue=*/false); // + 2 to add padding on both sides. + + // Rasterize chart and dilate. + drawChartBitmapDilate(chart, &chart_bitmap, /*padding=*/1); + } + else { + // Init all bits to 0. + chart_bitmap.resize(ftoi_ceil(chartExtents[c].x) + 1, ftoi_ceil(chartExtents[c].y) + 1, /*initValue=*/false); // Add half a texels on each side. + + // Rasterize chart and dilate. + drawChartBitmap(chart, &chart_bitmap, Vector2(1), Vector2(0.5)); + } + } + + int best_x, best_y; + int best_cw, best_ch; // Includes padding now. + int best_r; + findChartLocation(quality, &chart_bitmap, chartExtents[c], w, h, &best_x, &best_y, &best_cw, &best_ch, &best_r); + + /*if (w < best_x + best_cw || h < best_y + best_ch) + { + nvDebug("Resize extents to (%d, %d).\n", best_x + best_cw, best_y + best_ch); + }*/ + + // Update parametric extents. + w = max(w, best_x + best_cw); + h = max(h, best_y + best_ch); + + w = align(w, 4); + h = align(h, 4); + + // Resize bitmap if necessary. + if (uint(w) > m_bitmap.width() || uint(h) > m_bitmap.height()) + { + //nvDebug("Resize bitmap (%d, %d).\n", nextPowerOfTwo(w), nextPowerOfTwo(h)); + m_bitmap.resize(nextPowerOfTwo(U32(w)), nextPowerOfTwo(U32(h)), false); + m_debug_bitmap.resize(nextPowerOfTwo(U32(w)), nextPowerOfTwo(U32(h))); + } + + //nvDebug("Add chart at (%d, %d).\n", best_x, best_y); + + addChart(&chart_bitmap, w, h, best_x, best_y, best_r, /*debugOutput=*/NULL); + + // IC: Output chart again to debug bitmap. + if (chart->isVertexMapped()) { + addChart(&chart_bitmap, w, h, best_x, best_y, best_r, &m_debug_bitmap); + } + else { + addChart(chart, w, h, best_x, best_y, best_r, &m_debug_bitmap); + } + + //float best_angle = 2 * PI * best_r; + + // Translate and rotate chart texture coordinates. + HalfEdge::Mesh * mesh = chart->chartMesh(); + const uint vertexCount = mesh->vertexCount(); + for (uint v = 0; v < vertexCount; v++) + { + HalfEdge::Vertex * vertex = mesh->vertexAt(v); + + Vector2 t = vertex->tex; + if (best_r) swap(t.x, t.y); + //vertex->tex.x = best_x + t.x * cosf(best_angle) - t.y * sinf(best_angle); + //vertex->tex.y = best_y + t.x * sinf(best_angle) + t.y * cosf(best_angle); + + vertex->tex.x = best_x + t.x + 0.5f; + vertex->tex.y = best_y + t.y + 0.5f; + + nvCheck(vertex->tex.x >= 0 && vertex->tex.y >= 0); + nvCheck(isFinite(vertex->tex.x) && isFinite(vertex->tex.y)); + } + +#if DEBUG_OUTPUT && 0 + StringBuilder fileName; + fileName.format("debug_packer_%d.tga", i); + //outputDebugBitmap(fileName.str(), m_bitmap, w, h); + outputDebugImage(fileName.str(), m_debug_bitmap, w, h); +#endif + } + +#else // 0 + + // Add sorted charts to bitmap. + for (uint i = 0; i < chartCount; i++) + { + uint c = ranks[chartCount - i - 1]; // largest chart first + + Chart * chart = m_atlas->chartAt(c); + + if (!chart->isDisk()) continue; + + Vector2 scale(1, 1); + +#if 0 // old method. + //m_padding_x = 2*padding; + //m_padding_y = 2*padding; +#else + //m_padding_x = 0; //padding; + //m_padding_y = 0; //padding; +#endif + + int bw = ftoi_ceil(chartExtents[c].x + 1); + int bh = ftoi_ceil(chartExtents[c].y + 1); + + if (chartExtents[c].x < 1.0f) { + scale.x = 0.01f; // @@ Ideally we would like to scale it to 0, but then our rasterizer would not touch any pixels. + bw = 1; + } + if (chartExtents[c].y < 1.0f) { + scale.y = 0.01f; + bh = 1; + } + + //BitMap chart_bitmap(iceil(chartExtents[c].x) + 1 + m_padding_x * 2, iceil(chartExtents[c].y) + 1 + m_padding_y * 2); + //BitMap chart_bitmap(ftoi_ceil(chartExtents[c].x/2)*2, ftoi_ceil(chartExtents[c].y/2)*2); + BitMap chart_bitmap(bw, bh); + chart_bitmap.clearAll(); + + Vector2 offset; + offset.x = 0; // (chart_bitmap.width() - chartExtents[c].x) * 0.5f; + offset.y = 0; // (chart_bitmap.height() - chartExtents[c].y) * 0.5f; + + drawChartBitmap(chart, &chart_bitmap, scale, offset); + + int best_x, best_y; + int best_cw, best_ch; + int best_r; + findChartLocation(quality, &chart_bitmap, chartExtents[c], w, h, &best_x, &best_y, &best_cw, &best_ch, &best_r); + + /*if (w < best_x + best_cw || h < best_y + best_ch) + { + nvDebug("Resize extents to (%d, %d).\n", best_x + best_cw, best_y + best_ch); + }*/ + + // Update parametric extents. + w = max(w, best_x + best_cw); + h = max(h, best_y + best_ch); + + // Resize bitmap if necessary. + if (uint(w) > m_bitmap.width() || uint(h) > m_bitmap.height()) + { + //nvDebug("Resize bitmap (%d, %d).\n", nextPowerOfTwo(w), nextPowerOfTwo(h)); + m_bitmap.resize(nextPowerOfTwo(w), nextPowerOfTwo(h), false); + m_debug_bitmap.resize(nextPowerOfTwo(w), nextPowerOfTwo(h)); + } + + //nvDebug("Add chart at (%d, %d).\n", best_x, best_y); + +#if 0 // old method. +#if _DEBUG + checkCanAddChart(chart, w, h, best_x, best_y, best_r); +#endif + + // Add chart. + addChart(chart, w, h, best_x, best_y, best_r); +#else + // Add chart reusing its bitmap. + addChart(&chart_bitmap, w, h, best_x, best_y, best_r); +#endif + + //float best_angle = 2 * PI * best_r; + + // Translate and rotate chart texture coordinates. + HalfEdge::Mesh * mesh = chart->chartMesh(); + const uint vertexCount = mesh->vertexCount(); + for (uint v = 0; v < vertexCount; v++) + { + HalfEdge::Vertex * vertex = mesh->vertexAt(v); + + Vector2 t = vertex->tex * scale + offset; + if (best_r) swap(t.x, t.y); + //vertex->tex.x = best_x + t.x * cosf(best_angle) - t.y * sinf(best_angle); + //vertex->tex.y = best_y + t.x * sinf(best_angle) + t.y * cosf(best_angle); + vertex->tex.x = best_x + t.x + 0.5f; + vertex->tex.y = best_y + t.y + 0.5f; + + nvCheck(vertex->tex.x >= 0 && vertex->tex.y >= 0); + } + +#if DEBUG_OUTPUT && 0 + StringBuilder fileName; + fileName.format("debug_packer_%d.tga", i); + //outputDebugBitmap(fileName.str(), m_bitmap, w, h); + outputDebugImage(fileName.str(), m_debug_bitmap, w, h); +#endif + } + +#endif // 0 + + //w -= padding - 1; // Leave one pixel border! + //h -= padding - 1; + + m_width = max(0, w); + m_height = max(0, h); + + nvCheck(isAligned(m_width, 4)); + nvCheck(isAligned(m_height, 4)); + + m_debug_bitmap.resize(m_width, m_height); + m_debug_bitmap.setFormat(Image::Format_ARGB); + +#if DEBUG_OUTPUT + //outputDebugBitmap("debug_packer_final.tga", m_bitmap, w, h); + //outputDebugImage("debug_packer_final.tga", m_debug_bitmap, w, h); + ImageIO::save("debug_packer_final.tga", &m_debug_bitmap); +#endif +} + + +// IC: Brute force is slow, and random may take too much time to converge. We start inserting large charts in a small atlas. Using brute force is lame, because most of the space +// is occupied at this point. At the end we have many small charts and a large atlas with sparse holes. Finding those holes randomly is slow. A better approach would be to +// start stacking large charts as if they were tetris pieces. Once charts get small try to place them randomly. It may be interesting to try a intermediate strategy, first try +// along one axis and then try exhaustively along that axis. +void AtlasPacker::findChartLocation(int quality, const BitMap * bitmap, Vector2::Arg extents, int w, int h, int * best_x, int * best_y, int * best_w, int * best_h, int * best_r) +{ + int attempts = 256; + if (quality == 1) attempts = 4096; + if (quality == 2) attempts = 2048; + if (quality == 3) attempts = 1024; + if (quality == 4) attempts = 512; + + if (quality == 0 || w*h < attempts) + { + findChartLocation_bruteForce(bitmap, extents, w, h, best_x, best_y, best_w, best_h, best_r); + } + else + { + findChartLocation_random(bitmap, extents, w, h, best_x, best_y, best_w, best_h, best_r, attempts); + } +} + +#define BLOCK_SIZE 4 + +void AtlasPacker::findChartLocation_bruteForce(const BitMap * bitmap, Vector2::Arg extents, int w, int h, int * best_x, int * best_y, int * best_w, int * best_h, int * best_r) +{ + int best_metric = INT_MAX; + + // Try two different orientations. + for (int r = 0; r < 2; r++) + { + int cw = bitmap->width(); + int ch = bitmap->height(); + if (r & 1) swap(cw, ch); + + for (int y = 0; y <= h + 1; y += BLOCK_SIZE) // + 1 to extend atlas in case atlas full. + { + for (int x = 0; x <= w + 1; x += BLOCK_SIZE) // + 1 not really necessary here. + { + // Early out. + int area = max(w, x+cw) * max(h, y+ch); + //int perimeter = max(w, x+cw) + max(h, y+ch); + int extents = max(max(w, x+cw), max(h, y+ch)); + + int metric = extents*extents + area; + + if (metric > best_metric) { + continue; + } + if (metric == best_metric && max(x, y) >= max(*best_x, *best_y)) { + // If metric is the same, pick the one closest to the origin. + continue; + } + + if (canAddChart(bitmap, w, h, x, y, r)) + { + best_metric = metric; + *best_x = x; + *best_y = y; + *best_w = cw; + *best_h = ch; + *best_r = r; + + if (area == w*h) + { + // Chart is completely inside, do not look at any other location. + goto done; + } + } + } + } + } + +done: + nvDebugCheck (best_metric != INT_MAX); +} + + +void AtlasPacker::findChartLocation_random(const BitMap * bitmap, Vector2::Arg extents, int w, int h, int * best_x, int * best_y, int * best_w, int * best_h, int * best_r, int minTrialCount) +{ + int best_metric = INT_MAX; + + for (int i = 0; i < minTrialCount || best_metric == INT_MAX; i++) + { + int r = m_rand.getRange(1); + int x = m_rand.getRange(w + 1); // + 1 to extend atlas in case atlas full. We may want to use a higher number to increase probability of extending atlas. + int y = m_rand.getRange(h + 1); // + 1 to extend atlas in case atlas full. + + x = align(x, BLOCK_SIZE); + y = align(y, BLOCK_SIZE); + + int cw = bitmap->width(); + int ch = bitmap->height(); + if (r & 1) swap(cw, ch); + + // Early out. + int area = max(w, x+cw) * max(h, y+ch); + //int perimeter = max(w, x+cw) + max(h, y+ch); + int extents = max(max(w, x+cw), max(h, y+ch)); + + int metric = extents*extents + area; + + if (metric > best_metric) { + continue; + } + if (metric == best_metric && min(x, y) > min(*best_x, *best_y)) { + // If metric is the same, pick the one closest to the origin. + continue; + } + + if (canAddChart(bitmap, w, h, x, y, r)) + { + best_metric = metric; + *best_x = x; + *best_y = y; + *best_w = cw; + *best_h = ch; + *best_r = r; + + if (area == w*h) + { + // Chart is completely inside, do not look at any other location. + break; + } + } + } +} + + +void AtlasPacker::drawChartBitmapDilate(const Chart * chart, BitMap * bitmap, int padding) +{ + const int w = bitmap->width(); + const int h = bitmap->height(); + const Vector2 extents = Vector2(float(w), float(h)); + + // Rasterize chart faces, check that all bits are not set. + const uint faceCount = chart->faceCount(); + for (uint f = 0; f < faceCount; f++) + { + const HalfEdge::Face * face = chart->chartMesh()->faceAt(f); + + Vector2 vertices[4]; + + uint edgeCount = 0; + for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance()) + { + if (edgeCount < 4) + { + vertices[edgeCount] = it.vertex()->tex + Vector2(0.5) + Vector2(float(padding), float(padding)); + } + edgeCount++; + } + + if (edgeCount == 3) + { + Raster::drawTriangle(Raster::Mode_Antialiased, extents, true, vertices, AtlasPacker::setBitsCallback, bitmap); + } + else + { + Raster::drawQuad(Raster::Mode_Antialiased, extents, true, vertices, AtlasPacker::setBitsCallback, bitmap); + } + } + + // Expand chart by padding pixels. (dilation) + BitMap tmp(w, h); + for (int i = 0; i < padding; i++) { + tmp.clearAll(); + + for (int y = 0; y < h; y++) { + for (int x = 0; x < w; x++) { + bool b = bitmap->bitAt(x, y); + if (!b) { + if (x > 0) { + b |= bitmap->bitAt(x - 1, y); + if (y > 0) b |= bitmap->bitAt(x - 1, y - 1); + if (y < h-1) b |= bitmap->bitAt(x - 1, y + 1); + } + if (y > 0) b |= bitmap->bitAt(x, y - 1); + if (y < h-1) b |= bitmap->bitAt(x, y + 1); + if (x < w-1) { + b |= bitmap->bitAt(x + 1, y); + if (y > 0) b |= bitmap->bitAt(x + 1, y - 1); + if (y < h-1) b |= bitmap->bitAt(x + 1, y + 1); + } + } + if (b) tmp.setBitAt(x, y); + } + } + + swap(tmp, *bitmap); + } +} + + +void AtlasPacker::drawChartBitmap(const Chart * chart, BitMap * bitmap, const Vector2 & scale, const Vector2 & offset) +{ + const int w = bitmap->width(); + const int h = bitmap->height(); + const Vector2 extents = Vector2(float(w), float(h)); + + static const Vector2 pad[4] = { + Vector2(-0.5, -0.5), + Vector2(0.5, -0.5), + Vector2(-0.5, 0.5), + Vector2(0.5, 0.5) + }; + /*static const Vector2 pad[4] = { + Vector2(-1, -1), + Vector2(1, -1), + Vector2(-1, 1), + Vector2(1, 1) + };*/ + + // Rasterize 4 times to add proper padding. + for (int i = 0; i < 4; i++) { + + // Rasterize chart faces, check that all bits are not set. + const uint faceCount = chart->chartMesh()->faceCount(); + for (uint f = 0; f < faceCount; f++) + { + const HalfEdge::Face * face = chart->chartMesh()->faceAt(f); + + Vector2 vertices[4]; + + uint edgeCount = 0; + for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance()) + { + if (edgeCount < 4) + { + vertices[edgeCount] = it.vertex()->tex * scale + offset + pad[i]; + nvCheck(ftoi_ceil(vertices[edgeCount].x) >= 0); + nvCheck(ftoi_ceil(vertices[edgeCount].y) >= 0); + nvCheck(ftoi_ceil(vertices[edgeCount].x) <= w); + nvCheck(ftoi_ceil(vertices[edgeCount].y) <= h); + } + edgeCount++; + } + + if (edgeCount == 3) + { + Raster::drawTriangle(Raster::Mode_Antialiased, extents, /*enableScissors=*/true, vertices, AtlasPacker::setBitsCallback, bitmap); + } + else + { + Raster::drawQuad(Raster::Mode_Antialiased, extents, /*enableScissors=*/true, vertices, AtlasPacker::setBitsCallback, bitmap); + } + } + } + + // @@ This only allows us to expand the size in texel intervals. + /*if (m_padding_x != 0 && m_padding_y != 0)*/ { + + // Expand chart by padding pixels. (dilation) + BitMap tmp(w, h); + //for (int i = 0; i < 1; i++) { + tmp.clearAll(); + + for (int y = 0; y < h; y++) { + for (int x = 0; x < w; x++) { + bool b = bitmap->bitAt(x, y); + if (!b) { + if (x > 0) { + b |= bitmap->bitAt(x - 1, y); + if (y > 0) b |= bitmap->bitAt(x - 1, y - 1); + if (y < h-1) b |= bitmap->bitAt(x - 1, y + 1); + } + if (y > 0) b |= bitmap->bitAt(x, y - 1); + if (y < h-1) b |= bitmap->bitAt(x, y + 1); + if (x < w-1) { + b |= bitmap->bitAt(x + 1, y); + if (y > 0) b |= bitmap->bitAt(x + 1, y - 1); + if (y < h-1) b |= bitmap->bitAt(x + 1, y + 1); + } + } + if (b) tmp.setBitAt(x, y); + } + } + + swap(tmp, *bitmap); + //} + } +} + +bool AtlasPacker::canAddChart(const BitMap * bitmap, int atlas_w, int atlas_h, int offset_x, int offset_y, int r) +{ + nvDebugCheck(r == 0 || r == 1); + + // Check whether the two bitmaps overlap. + + const int w = bitmap->width(); + const int h = bitmap->height(); + + if (r == 0) { + for (int y = 0; y < h; y++) { + int yy = y + offset_y; + if (yy >= 0) { + for (int x = 0; x < w; x++) { + int xx = x + offset_x; + if (xx >= 0) { + if (bitmap->bitAt(x, y)) { + if (xx < atlas_w && yy < atlas_h) { + if (m_bitmap.bitAt(xx, yy)) return false; + } + } + } + } + } + } + } + else if (r == 1) { + for (int y = 0; y < h; y++) { + int xx = y + offset_x; + if (xx >= 0) { + for (int x = 0; x < w; x++) { + int yy = x + offset_y; + if (yy >= 0) { + if (bitmap->bitAt(x, y)) { + if (xx < atlas_w && yy < atlas_h) { + if (m_bitmap.bitAt(xx, yy)) return false; + } + } + } + } + } + } + } + + return true; +} + +#if 0 +void AtlasPacker::checkCanAddChart(const Chart * chart, int w, int h, int x, int y, int r) +{ + nvDebugCheck(r == 0 || r == 1); + Vector2 extents = Vector2(float(w), float(h)); + Vector2 offset = Vector2(float(x), float(y)); + + // Rasterize chart faces, set bits. + const uint faceCount = chart->faceCount(); + for (uint f = 0; f < faceCount; f++) + { + const HalfEdge::Face * face = chart->chartMesh()->faceAt(f); + + Vector2 vertices[4]; + + uint edgeCount = 0; + for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance()) + { + if (edgeCount < 4) + { + Vector2 t = it.vertex()->tex; + if (r == 1) swap(t.x, t.y); + vertices[edgeCount] = t + offset; + } + edgeCount++; + } + + if (edgeCount == 3) + { + Raster::drawTriangle(Raster::Mode_Antialiased, extents, /*enableScissors=*/true, vertices, AtlasPacker::checkBitsCallback, &m_bitmap); + } + else + { + Raster::drawQuad(Raster::Mode_Antialiased, extents, /*enableScissors=*/true, vertices, AtlasPacker::checkBitsCallback, &m_bitmap); + } + } +} +#endif // 0 + + +static Color32 chartColor = Color32(0); +static void selectRandomColor(MTRand & rand) { + // Pick random color for this chart. @@ Select random hue, but fixed saturation/luminance? + chartColor.r = 128 + rand.getRange(127); + chartColor.g = 128 + rand.getRange(127); + chartColor.b = 128 + rand.getRange(127); + chartColor.a = 255; +} +static bool debugDrawCallback(void * param, int x, int y, Vector3::Arg, Vector3::Arg, Vector3::Arg, float area) +{ + Image * image = (Image *)param; + + if (area > 0.0) { + Color32 c = image->pixel(x, y); + c.r = chartColor.r; + c.g = chartColor.g; + c.b = chartColor.b; + c.a += U8(ftoi_round(0.5f * area * 255)); + image->pixel(x, y) = c; + } + + return true; +} + +void AtlasPacker::addChart(const Chart * chart, int w, int h, int x, int y, int r, Image * debugOutput) +{ + nvDebugCheck(r == 0 || r == 1); + + nvDebugCheck(debugOutput != NULL); + selectRandomColor(m_rand); + + Vector2 extents = Vector2(float(w), float(h)); + Vector2 offset = Vector2(float(x), float(y)) + Vector2(0.5); + + // Rasterize chart faces, set bits. + const uint faceCount = chart->faceCount(); + for (uint f = 0; f < faceCount; f++) + { + const HalfEdge::Face * face = chart->chartMesh()->faceAt(f); + + Vector2 vertices[4]; + + uint edgeCount = 0; + for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance()) + { + if (edgeCount < 4) + { + Vector2 t = it.vertex()->tex; + if (r == 1) swap(t.x, t.y); + vertices[edgeCount] = t + offset; + } + edgeCount++; + } + + if (edgeCount == 3) + { + Raster::drawTriangle(Raster::Mode_Antialiased, extents, /*enableScissors=*/true, vertices, debugDrawCallback, debugOutput); + } + else + { + Raster::drawQuad(Raster::Mode_Antialiased, extents, /*enableScissors=*/true, vertices, debugDrawCallback, debugOutput); + } + } +} + + +void AtlasPacker::addChart(const BitMap * bitmap, int atlas_w, int atlas_h, int offset_x, int offset_y, int r, Image * debugOutput) +{ + nvDebugCheck(r == 0 || r == 1); + + // Check whether the two bitmaps overlap. + + const int w = bitmap->width(); + const int h = bitmap->height(); + + if (debugOutput != NULL) { + selectRandomColor(m_rand); + } + + if (r == 0) { + for (int y = 0; y < h; y++) { + int yy = y + offset_y; + if (yy >= 0) { + for (int x = 0; x < w; x++) { + int xx = x + offset_x; + if (xx >= 0) { + if (bitmap->bitAt(x, y)) { + if (xx < atlas_w && yy < atlas_h) { + if (debugOutput) debugOutput->pixel(xx, yy) = chartColor; + else { + nvDebugCheck(m_bitmap.bitAt(xx, yy) == false); + m_bitmap.setBitAt(xx, yy); + } + } + } + } + } + } + } + } + else if (r == 1) { + for (int y = 0; y < h; y++) { + int xx = y + offset_x; + if (xx >= 0) { + for (int x = 0; x < w; x++) { + int yy = x + offset_y; + if (yy >= 0) { + if (bitmap->bitAt(x, y)) { + if (xx < atlas_w && yy < atlas_h) { + if (debugOutput) debugOutput->pixel(xx, yy) = chartColor; + else { + nvDebugCheck(m_bitmap.bitAt(xx, yy) == false); + m_bitmap.setBitAt(xx, yy); + } + } + } + } + } + } + } + } +} + + + +/*static*/ bool AtlasPacker::checkBitsCallback(void * param, int x, int y, Vector3::Arg, Vector3::Arg, Vector3::Arg, float) +{ + BitMap * bitmap = (BitMap * )param; + + nvDebugCheck(bitmap->bitAt(x, y) == false); + + return true; +} + +/*static*/ bool AtlasPacker::setBitsCallback(void * param, int x, int y, Vector3::Arg, Vector3::Arg, Vector3::Arg, float area) +{ + BitMap * bitmap = (BitMap * )param; + + if (area > 0.0) { + bitmap->setBitAt(x, y); + } + + return true; +} + + + +float AtlasPacker::computeAtlasUtilization() const { + const uint w = m_width; + const uint h = m_height; + nvDebugCheck(w <= m_bitmap.width()); + nvDebugCheck(h <= m_bitmap.height()); + + uint count = 0; + for (uint y = 0; y < h; y++) { + for (uint x = 0; x < w; x++) { + count += m_bitmap.bitAt(x, y); + } + } + + return float(count) / (w * h); +} |