Examples with AABB org.jbox2d.collision.AABB used on opensource projects

Example 1 with AABB

use of org.jbox2d.collision.AABB in project libgdx by libgdx.

the class DynamicTree method raycast.

@Override
public void raycast(TreeRayCastCallback callback, RayCastInput input) {
    final Vec2 p1 = input.p1;
    final Vec2 p2 = input.p2;
    float p1x = p1.x, p2x = p2.x, p1y = p1.y, p2y = p2.y;
    float vx, vy;
    float rx, ry;
    float absVx, absVy;
    float cx, cy;
    float hx, hy;
    float tempx, tempy;
    r.x = p2x - p1x;
    r.y = p2y - p1y;
    assert ((r.x * r.x + r.y * r.y) > 0f);
    r.normalize();
    rx = r.x;
    ry = r.y;
    // v is perpendicular to the segment.
    vx = -1f * ry;
    vy = 1f * rx;
    absVx = MathUtils.abs(vx);
    absVy = MathUtils.abs(vy);
    // Separating axis for segment (Gino, p80).
    // |dot(v, p1 - c)| > dot(|v|, h)
    float maxFraction = input.maxFraction;
    // Build a bounding box for the segment.
    final AABB segAABB = aabb;
    // Vec2 t = p1 + maxFraction * (p2 - p1);
    // before inline
    // temp.set(p2).subLocal(p1).mulLocal(maxFraction).addLocal(p1);
    // Vec2.minToOut(p1, temp, segAABB.lowerBound);
    // Vec2.maxToOut(p1, temp, segAABB.upperBound);
    tempx = (p2x - p1x) * maxFraction + p1x;
    tempy = (p2y - p1y) * maxFraction + p1y;
    segAABB.lowerBound.x = p1x < tempx ? p1x : tempx;
    segAABB.lowerBound.y = p1y < tempy ? p1y : tempy;
    segAABB.upperBound.x = p1x > tempx ? p1x : tempx;
    segAABB.upperBound.y = p1y > tempy ? p1y : tempy;
    // end inline
    nodeStackIndex = 0;
    nodeStack[nodeStackIndex++] = m_root;
    while (nodeStackIndex > 0) {
        final DynamicTreeNode node = nodeStack[--nodeStackIndex];
        if (node == null) {
            continue;
        }
        final AABB nodeAABB = node.aabb;
        if (!AABB.testOverlap(nodeAABB, segAABB)) {
            continue;
        }
        // Separating axis for segment (Gino, p80).
        // |dot(v, p1 - c)| > dot(|v|, h)
        // node.aabb.getCenterToOut(c);
        // node.aabb.getExtentsToOut(h);
        cx = (nodeAABB.lowerBound.x + nodeAABB.upperBound.x) * .5f;
        cy = (nodeAABB.lowerBound.y + nodeAABB.upperBound.y) * .5f;
        hx = (nodeAABB.upperBound.x - nodeAABB.lowerBound.x) * .5f;
        hy = (nodeAABB.upperBound.y - nodeAABB.lowerBound.y) * .5f;
        tempx = p1x - cx;
        tempy = p1y - cy;
        float separation = MathUtils.abs(vx * tempx + vy * tempy) - (absVx * hx + absVy * hy);
        if (separation > 0.0f) {
            continue;
        }
        if (node.child1 == null) {
            subInput.p1.x = p1x;
            subInput.p1.y = p1y;
            subInput.p2.x = p2x;
            subInput.p2.y = p2y;
            subInput.maxFraction = maxFraction;
            float value = callback.raycastCallback(subInput, node.id);
            if (value == 0.0f) {
                // The client has terminated the ray cast.
                return;
            }
            if (value > 0.0f) {
                // Update segment bounding box.
                maxFraction = value;
                // temp.set(p2).subLocal(p1).mulLocal(maxFraction).addLocal(p1);
                // Vec2.minToOut(p1, temp, segAABB.lowerBound);
                // Vec2.maxToOut(p1, temp, segAABB.upperBound);
                tempx = (p2x - p1x) * maxFraction + p1x;
                tempy = (p2y - p1y) * maxFraction + p1y;
                segAABB.lowerBound.x = p1x < tempx ? p1x : tempx;
                segAABB.lowerBound.y = p1y < tempy ? p1y : tempy;
                segAABB.upperBound.x = p1x > tempx ? p1x : tempx;
                segAABB.upperBound.y = p1y > tempy ? p1y : tempy;
            }
        } else {
            if (nodeStack.length - nodeStackIndex - 2 <= 0) {
                DynamicTreeNode[] newBuffer = new DynamicTreeNode[nodeStack.length * 2];
                System.arraycopy(nodeStack, 0, newBuffer, 0, nodeStack.length);
                nodeStack = newBuffer;
            }
            nodeStack[nodeStackIndex++] = node.child1;
            nodeStack[nodeStackIndex++] = node.child2;
        }
    }
}

Example 2 with AABB

use of org.jbox2d.collision.AABB in project libgdx by libgdx.

the class DynamicTree method rebuildBottomUp.

/**
   * Build an optimal tree. Very expensive. For testing.
   */
public void rebuildBottomUp() {
    int[] nodes = new int[m_nodeCount];
    int count = 0;
    // Build array of leaves. Free the rest.
    for (int i = 0; i < m_nodeCapacity; ++i) {
        if (m_nodes[i].height < 0) {
            // free node in pool
            continue;
        }
        DynamicTreeNode node = m_nodes[i];
        if (node.child1 == null) {
            node.parent = null;
            nodes[count] = i;
            ++count;
        } else {
            freeNode(node);
        }
    }
    AABB b = new AABB();
    while (count > 1) {
        float minCost = Float.MAX_VALUE;
        int iMin = -1, jMin = -1;
        for (int i = 0; i < count; ++i) {
            AABB aabbi = m_nodes[nodes[i]].aabb;
            for (int j = i + 1; j < count; ++j) {
                AABB aabbj = m_nodes[nodes[j]].aabb;
                b.combine(aabbi, aabbj);
                float cost = b.getPerimeter();
                if (cost < minCost) {
                    iMin = i;
                    jMin = j;
                    minCost = cost;
                }
            }
        }
        int index1 = nodes[iMin];
        int index2 = nodes[jMin];
        DynamicTreeNode child1 = m_nodes[index1];
        DynamicTreeNode child2 = m_nodes[index2];
        DynamicTreeNode parent = allocateNode();
        parent.child1 = child1;
        parent.child2 = child2;
        parent.height = 1 + MathUtils.max(child1.height, child2.height);
        parent.aabb.combine(child1.aabb, child2.aabb);
        parent.parent = null;
        child1.parent = parent;
        child2.parent = parent;
        nodes[jMin] = nodes[count - 1];
        nodes[iMin] = parent.id;
        --count;
    }
    m_root = m_nodes[nodes[0]];
    validate();
}

Example 3 with AABB

use of org.jbox2d.collision.AABB in project libgdx by libgdx.

the class DynamicTreeFlatNodes method createProxy.

@Override
public final int createProxy(final AABB aabb, Object userData) {
    final int node = allocateNode();
    // Fatten the aabb
    final AABB nodeAABB = m_aabb[node];
    nodeAABB.lowerBound.x = aabb.lowerBound.x - Settings.aabbExtension;
    nodeAABB.lowerBound.y = aabb.lowerBound.y - Settings.aabbExtension;
    nodeAABB.upperBound.x = aabb.upperBound.x + Settings.aabbExtension;
    nodeAABB.upperBound.y = aabb.upperBound.y + Settings.aabbExtension;
    m_userData[node] = userData;
    insertLeaf(node);
    return node;
}

Example 4 with AABB

use of org.jbox2d.collision.AABB in project libgdx by libgdx.

the class DynamicTreeFlatNodes method insertLeaf.

private final void insertLeaf(int leaf) {
    if (m_root == NULL_NODE) {
        m_root = leaf;
        m_parent[m_root] = NULL_NODE;
        return;
    }
    // find the best sibling
    AABB leafAABB = m_aabb[leaf];
    int index = m_root;
    while (m_child1[index] != NULL_NODE) {
        final int node = index;
        int child1 = m_child1[node];
        int child2 = m_child2[node];
        final AABB nodeAABB = m_aabb[node];
        float area = nodeAABB.getPerimeter();
        combinedAABB.combine(nodeAABB, leafAABB);
        float combinedArea = combinedAABB.getPerimeter();
        // Cost of creating a new parent for this node and the new leaf
        float cost = 2.0f * combinedArea;
        // Minimum cost of pushing the leaf further down the tree
        float inheritanceCost = 2.0f * (combinedArea - area);
        // Cost of descending into child1
        float cost1;
        AABB child1AABB = m_aabb[child1];
        if (m_child1[child1] == NULL_NODE) {
            combinedAABB.combine(leafAABB, child1AABB);
            cost1 = combinedAABB.getPerimeter() + inheritanceCost;
        } else {
            combinedAABB.combine(leafAABB, child1AABB);
            float oldArea = child1AABB.getPerimeter();
            float newArea = combinedAABB.getPerimeter();
            cost1 = (newArea - oldArea) + inheritanceCost;
        }
        // Cost of descending into child2
        float cost2;
        AABB child2AABB = m_aabb[child2];
        if (m_child1[child2] == NULL_NODE) {
            combinedAABB.combine(leafAABB, child2AABB);
            cost2 = combinedAABB.getPerimeter() + inheritanceCost;
        } else {
            combinedAABB.combine(leafAABB, child2AABB);
            float oldArea = child2AABB.getPerimeter();
            float newArea = combinedAABB.getPerimeter();
            cost2 = newArea - oldArea + inheritanceCost;
        }
        // Descend according to the minimum cost.
        if (cost < cost1 && cost < cost2) {
            break;
        }
        // Descend
        if (cost1 < cost2) {
            index = child1;
        } else {
            index = child2;
        }
    }
    int sibling = index;
    int oldParent = m_parent[sibling];
    final int newParent = allocateNode();
    m_parent[newParent] = oldParent;
    m_userData[newParent] = null;
    m_aabb[newParent].combine(leafAABB, m_aabb[sibling]);
    m_height[newParent] = m_height[sibling] + 1;
    if (oldParent != NULL_NODE) {
        // The sibling was not the root.
        if (m_child1[oldParent] == sibling) {
            m_child1[oldParent] = newParent;
        } else {
            m_child2[oldParent] = newParent;
        }
        m_child1[newParent] = sibling;
        m_child2[newParent] = leaf;
        m_parent[sibling] = newParent;
        m_parent[leaf] = newParent;
    } else {
        // The sibling was the root.
        m_child1[newParent] = sibling;
        m_child2[newParent] = leaf;
        m_parent[sibling] = newParent;
        m_parent[leaf] = newParent;
        m_root = newParent;
    }
    // Walk back up the tree fixing heights and AABBs
    index = m_parent[leaf];
    while (index != NULL_NODE) {
        index = balance(index);
        int child1 = m_child1[index];
        int child2 = m_child2[index];
        assert (child1 != NULL_NODE);
        assert (child2 != NULL_NODE);
        m_height[index] = 1 + MathUtils.max(m_height[child1], m_height[child2]);
        m_aabb[index].combine(m_aabb[child1], m_aabb[child2]);
        index = m_parent[index];
    }
// validate();
}

Example 5 with AABB

use of org.jbox2d.collision.AABB in project libgdx by libgdx.

the class DynamicTreeFlatNodes method expandBuffers.

private void expandBuffers(int oldSize, int newSize) {
    m_aabb = BufferUtils.reallocateBuffer(AABB.class, m_aabb, oldSize, newSize);
    m_userData = BufferUtils.reallocateBuffer(Object.class, m_userData, oldSize, newSize);
    m_parent = BufferUtils.reallocateBuffer(m_parent, oldSize, newSize);
    m_child1 = BufferUtils.reallocateBuffer(m_child1, oldSize, newSize);
    m_child2 = BufferUtils.reallocateBuffer(m_child2, oldSize, newSize);
    m_height = BufferUtils.reallocateBuffer(m_height, oldSize, newSize);
    // Build a linked list for the free list.
    for (int i = oldSize; i < newSize; i++) {
        m_aabb[i] = new AABB();
        m_parent[i] = (i == newSize - 1) ? NULL_NODE : i + 1;
        m_height[i] = -1;
        m_child1[i] = -1;
        m_child2[i] = -1;
    }
    m_freeList = oldSize;
}