Import thekla_atlas

As requested by reduz, an import of thekla_atlas into thirdparty/

1 files changed, 1379 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..f2156899ae
--- /dev/null
+++ b/thirdparty/thekla_atlas/nvmesh/param/AtlasPacker.cpp
@@ -0,0 +1,1379 @@
+// 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 void 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;
+    
+    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
+}
+
+
+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;
+            computeBoundingBox(chart, &majorAxis, &minorAxis, &origin, &end);
+
+            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);
+}