bspslicer.cpp

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/*
 * @file
 * @brief Based on the BSP_tool from botman's Half-Life BSP utilities
 */
#ifndef ANDROID
#include "bspslicer.h"
#include "../ports/system.h"
#include "../common/common.h"
#include "../shared/images.h"

#define DEPTH 3

static bool SL_CreatePNGFile (const char* filename, unsigned char* buffer, int width, int height)
{
    ScopedFile f;

    /* create the .bmp file... */
    if (FS_OpenFile(filename, &f, FILE_WRITE) == -1)
        return false;

    R_WritePNG(&f, buffer, width, height);

    return true;
}

#define IMAGE_BUFFER_SET_BLACK(buffer, offset) do {int i; for (i = 0; i < DEPTH; i++) {buffer[offset + i] = 0xFF; } } while(0);

static void SL_Bresenham (int x0, int y0, int x1, int y1, int width, int height, bool rotated, unsigned char* outputBuffer)
{
    int dy = y1 - y0;
    int dx = x1 - x0;
    int stepx, stepy;
    int offset;
    const int maxOffset = width * height * DEPTH;

    if (dy < 0) {
        dy = -dy;
        stepy = -1;
    } else {
        stepy = 1;
    }
    if (dx < 0) {
        dx = -dx;
        stepx = -1;
    } else {
        stepx = 1;
    }
    dy *= 2;
    dx *= 2;

    if (rotated)
        offset = x0 * DEPTH * height + y0;
    else
        offset = y0 * width * DEPTH + x0 * DEPTH;

    if (offset >= 0 && offset < maxOffset) {
        IMAGE_BUFFER_SET_BLACK(outputBuffer, offset);
    } else
        return;

    if (dx > dy) {
        int fraction = 2 * dy - (dx >> 1); /* same as 2*dy - dx */
        while (x0 != x1) {
            if (fraction >= 0) {
                y0 += stepy;
                fraction -= dx; /* same as fraction -= 2*dx */
            }
            x0 += stepx;
            fraction += dy; /* same as fraction -= 2*dy */

            if (rotated)
                offset = x0 * DEPTH * height + y0;
            else
                offset = y0 * width * DEPTH + x0 * DEPTH;

            if (offset >= 0 && offset < maxOffset) {
                IMAGE_BUFFER_SET_BLACK(outputBuffer, offset);
            } else
                return;
        }
    } else {
        int fraction = dx - (dy >> 1);
        while (y0 != y1) {
            if (fraction >= 0) {
                x0 += stepx;
                fraction -= dy;
            }
            y0 += stepy;
            fraction += dx;

            if (rotated)
                offset = x0 * DEPTH * height + y0;
            else
                offset = y0 * width * DEPTH + x0 * DEPTH;

            if (offset >= 0 && offset < maxOffset) {
                IMAGE_BUFFER_SET_BLACK(outputBuffer, offset);
            } else
                return;
        }
    }
}

static float SL_DistanceToIntersection (const vec3_t origin, const vec3_t vector, const vec3_t planeOrigin, const vec3_t planeNormal)
{
    const float d = -(DotProduct(planeNormal, planeOrigin));
    const float numerator = DotProduct(planeNormal, origin) + d;
    const float denominator = DotProduct(planeNormal, vector);

    if (fabs(denominator) < 0.00001)
        /* normal is orthogonal to vector, no intersection */
        return -1.0f;

    return -(numerator / denominator);
}

static bool SL_VectorIntersectPlane (const vec3_t origin, const vec3_t vector, const vec3_t planeOrigin, const vec3_t planeNormal, vec3_t intersectPoint)
{
    vec3_t v_temp;
    const float dist = SL_DistanceToIntersection(origin, vector, planeOrigin, planeNormal);
    if (dist < 0)
        return false;

    VectorScale(vector, dist, v_temp);
    VectorAdd(origin, v_temp, intersectPoint);

    return true;
}

static void SL_SliceTheWorld (const TR_TILE_TYPE* tile, const vec3_t mins, const vec3_t maxs, float stepsize, int scale, bool singleFile, bool multipleContour)
{
    vec3_t zDistance = { 0.0f, 0.0f, 0.0f };
    const vec3_t zNormal = { 0.0f, 0.0f, 1.0f };
    vec3_t v[2];
    vec3_t vTemp, intersectPoint;
    float lineX1, lineY1, lineX2, lineY2;
    bool first, both;
    char filename[MAX_QPATH];
    const float minX = mins[0];
    const float maxX = maxs[0];
    const float minY = mins[1];
    const float maxY = maxs[1];
    const float minZ = mins[2];
    const float maxZ = maxs[2];

    const int numberOfSlices = (int) ((maxZ - minZ) / stepsize);
    int width;
    int height;
    bool rotated = false;
    unsigned char* pictureBuffer;

    lineX1 = lineY1 = lineX2 = lineY2 = 0.0f;

    width = (int) (maxX - minX);
    height = (int) (maxY - minY);

    /* is the map higher than it is wide? */
    if (height > width) {
        rotated = true; /* rotate the map 90 degrees */
        width = (int) (maxY - minY); /* swap the width and height */
        height = (int) (maxX - minX);
    }

    height /= scale;
    width /= scale;

    pictureBuffer = Mem_AllocTypeN(unsigned char, width * height * DEPTH);

    for (int sliceIndex = 0; sliceIndex < numberOfSlices; sliceIndex++) {
        const float zHeight = minZ + (sliceIndex * stepsize);
        zDistance[2] = zHeight;

        /* if not doing a contour map then clear the buffer each pass... */
        if (!singleFile && !multipleContour)
            memset(pictureBuffer, 0, width * height * DEPTH);

        /* loop through all the faces of the BSP file... */
        for (int j = 0; j < tile->nummodels; j++) {
            const dBspModel_t* model = &tile->models[j];
            for (int faceIndex = 0; faceIndex < model->numfaces; faceIndex++) {
                const dBspSurface_t* face = &tile->faces[model->firstface + faceIndex];
                const dBspTexinfo_t* texinfo = &tile->texinfo[face->texinfo];
                if (texinfo->surfaceFlags & (SURF_NODRAW|SURF_HINT|SURF_SKIP|SURF_BLEND33|SURF_BLEND66))
                    continue;
                first = true;
                both = false;

                /* for each face, loop though all of the edges, getting the vertexes... */
                for (int edgeIndex = 0; edgeIndex < face->numedges; edgeIndex++) {
                    /* get the coordinates of the vertex of this edge... */
                    int edge = tile->surfedges[face->firstedge + edgeIndex];

                    if (edge < 0) {
                        edge = -edge;
                        const dBspEdge_t* e = &tile->edges[edge];
                        v[0][0] = tile->vertexes[e->v[1]].point[0];
                        v[0][1] = tile->vertexes[e->v[1]].point[1];
                        v[0][2] = tile->vertexes[e->v[1]].point[2];
                    } else {
                        const dBspEdge_t* e = &tile->edges[edge];
                        v[0][0] = tile->vertexes[e->v[0]].point[0];
                        v[0][1] = tile->vertexes[e->v[0]].point[1];
                        v[0][2] = tile->vertexes[e->v[0]].point[2];
                    }

                    /* get the coordinates of the vertex of the next edge... */
                    edge = tile->surfedges[face->firstedge
                            + ((edgeIndex + 1) % face->numedges)];

                    if (edge < 0) {
                        edge = -edge;
                        const dBspEdge_t* e = &tile->edges[edge];
                        v[1][0] = tile->vertexes[e->v[1]].point[0];
                        v[1][1] = tile->vertexes[e->v[1]].point[1];
                        v[1][2] = tile->vertexes[e->v[1]].point[2];
                    } else {
                        const dBspEdge_t* e = &tile->edges[edge];
                        v[1][0] = tile->vertexes[e->v[0]].point[0];
                        v[1][1] = tile->vertexes[e->v[0]].point[1];
                        v[1][2] = tile->vertexes[e->v[0]].point[2];
                    }

                    /* vector from v[0] to v[1] intersect the Z plane? */
                    if (((v[0][2] < zHeight) && (v[1][2] > zHeight))
                            || ((v[1][2] < zHeight) && (v[0][2] > zHeight))) {
                        /* create a normalized vector between the 2 vertexes... */
                        VectorSubtract(v[1], v[0], vTemp);
                        VectorNormalize(vTemp);

                        /* find the point where the vector intersects the Z plane... */
                        SL_VectorIntersectPlane(v[0], vTemp, zDistance,
                                zNormal, intersectPoint);

                        /* is this the first or second Z plane intersection point? */
                        if (first) {
                            first = false;
                            lineX1 = intersectPoint[0];
                            lineY1 = intersectPoint[1];
                        } else {
                            both = true;
                            lineX2 = intersectPoint[0];
                            lineY2 = intersectPoint[1];
                        }
                    }

                    /* move v[1] to v[0] */
                    VectorCopy(v[1], v[0]);
                }

                /* did we find 2 points that intersected the Z plane? */
                if (both) {
                    /* offset by min_x to start at 0 */
                    lineX1 -= minX;
                    lineX2 -= minX;
                    /* offset by min_y to start at 0 */
                    lineY1 -= minY;
                    lineY2 -= minY;

                    lineX1 = lineX1 / scale;
                    lineY1 = lineY1 / scale;
                    lineX2 = lineX2 / scale;
                    lineY2 = lineY2 / scale;

                    /* are these points within the bounding box of the world? */
                    if (lineX1 >= 0 && lineX1 < width && lineY1 >= 0 && lineY1 < height
                            && lineX2 >= 0 && lineX2 < width && lineY2 >= 0 && lineY2 < height) {
                        const int x1 = (int) lineX1;
                        const int y1 = (int) lineY1;
                        const int x2 = (int) lineX2;
                        const int y2 = (int) lineY2;

                        if (rotated)
                            SL_Bresenham(x1, height - y1, x2, height - y2, width, height, rotated, pictureBuffer);
                        else
                            SL_Bresenham(x1, y1, x2, y2, width, height, rotated, pictureBuffer);
                    }
                }
            }
        }

        if (!singleFile) {
            Com_sprintf(filename, sizeof(filename), "out%d.png", sliceIndex + 1);
            Com_Printf("creating %s...\n", filename);
            SL_CreatePNGFile(filename, pictureBuffer, width, height);
        }
    }

    if (singleFile) {
        Q_strncpyz(filename, "out.png", sizeof(filename));
        Com_Printf("creating %s...\n", filename);
        SL_CreatePNGFile(filename, pictureBuffer, width, height);
    }

    Mem_Free(pictureBuffer);
}

void SL_BSPSlice (const TR_TILE_TYPE* model, float thickness, int scale, bool singleFile, bool multipleContour)
{
    vec3_t mins = {-MAX_WORLD_WIDTH, -MAX_WORLD_WIDTH, 0};
    vec3_t maxs = {MAX_WORLD_WIDTH, MAX_WORLD_WIDTH, (PATHFINDING_HEIGHT - 1) * UNIT_HEIGHT};

    if (model == nullptr)
        return;

    for (int i = 0; i < model->nummodels; i++) {
        const dBspModel_t* d = &model->models[i];
        AddPointToBounds(d->dbmBox.mins, mins, maxs);
        AddPointToBounds(d->dbmBox.maxs, mins, maxs);
    }

    /* don't start or end on exact multiples of the Z slice thickness
     * (if you do, it causes "weirdness" in the plane intersect function) */

    /* offset a tiny bit */
    mins[2] = (float) floor(mins[2]) + 0.01f;
    maxs[2] = (float) floor(maxs[2]) + 0.01f;

    SL_SliceTheWorld(model, mins, maxs, thickness, scale, singleFile, multipleContour);
}

#endif