first commit

ios/include/filament/Frustum.h

@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//! \file
+
+#ifndef TNT_FILAMENT_FRUSTUM_H
+#define TNT_FILAMENT_FRUSTUM_H
+
+#include <utils/compiler.h>
+
+#include <math/mat4.h>
+#include <math/vec3.h>
+
+#include <utils/unwindows.h> // Because we define NEAR and FAR in the Plane enum.
+
+namespace filament {
+
+class Box;
+class Culler;
+
+/**
+ * A frustum defined by six planes
+ */
+class UTILS_PUBLIC Frustum {
+public:
+    enum class Plane : uint8_t {
+        LEFT,
+        RIGHT,
+        BOTTOM,
+        TOP,
+        FAR,
+        NEAR
+    };
+
+    Frustum() = default;
+    Frustum(const Frustum& rhs) = default;
+    Frustum(Frustum&& rhs) noexcept = default;
+    Frustum& operator=(const Frustum& rhs) = default;
+    Frustum& operator=(Frustum&& rhs) noexcept = default;
+
+    /**
+     * Creates a frustum from a projection matrix (usually the projection * view matrix)
+     * @param pv a 4x4 projection matrix
+     */
+    explicit Frustum(const math::mat4f& pv);
+
+    /**
+     * Creates a frustum from 8 corner coordinates.
+     * @param corners the corners of the frustum
+     *
+     * The corners should be specified in this order:
+     * 0. far bottom left
+     * 1. far bottom right
+     * 2. far top left
+     * 3. far top right
+     * 4. near bottom left
+     * 5. near bottom right
+     * 6. near top left
+     * 7. near top right
+     *
+     *     2----3
+     *    /|   /|
+     *   6----7 |
+     *   | 0--|-1      far
+     *   |/   |/       /
+     *   4----5      near
+     *
+     */
+    explicit Frustum(const math::float3 corners[8]);
+
+    /**
+     * Sets the frustum from the given projection matrix
+     * @param pv a 4x4 projection matrix
+     */
+    void setProjection(const math::mat4f& pv);
+
+    /**
+     * Returns the plane equation parameters with normalized normals
+     * @param plane Identifier of the plane to retrieve the equation of
+     * @return A plane equation encoded a float4 R such as R.x*x + R.y*y + R.z*z + R.w = 0
+     */
+    math::float4 getNormalizedPlane(Plane plane) const noexcept;
+
+    /**
+     * Returns a copy of all six frustum planes in left, right, bottom, top, far, near order
+     * @param planes six plane equations encoded as in getNormalizedPlane() in
+     *              left, right, bottom, top, far, near order
+     */
+    void getNormalizedPlanes(math::float4 planes[6]) const noexcept;
+
+    /**
+     * Returns all six frustum planes in left, right, bottom, top, far, near order
+     * @return six plane equations encoded as in getNormalizedPlane() in
+     *              left, right, bottom, top, far, near order
+     */
+    math::float4 const* getNormalizedPlanes() const noexcept { return mPlanes; }
+
+    /**
+     * Returns whether a box intersects the frustum (i.e. is visible)
+     * @param box The box to test against the frustum
+     * @return true if the box may intersects the frustum, false otherwise. In some situations
+     * a box that doesn't intersect the frustum might be reported as though it does. However,
+     * a box that does intersect the frustum is always reported correctly (true).
+     */
+    bool intersects(const Box& box) const noexcept;
+
+    /**
+     * Returns whether a sphere intersects the frustum (i.e. is visible)
+     * @param sphere A sphere encoded as a center + radius.
+     * @return true if the sphere may intersects the frustum, false otherwise. In some situations
+     * a sphere that doesn't intersect the frustum might be reported as though it does. However,
+     * a sphere that does intersect the frustum is always reported correctly (true).
+     */
+    bool intersects(const math::float4& sphere) const noexcept;
+
+    /**
+     * Returns whether the frustum contains a given point.
+     * @param p the point to test
+     * @return the maximum signed distance to the frustum. Negative if p is inside.
+     */
+    float contains(math::float3 p) const noexcept;
+
+private:
+    friend class Culler;
+    math::float4 mPlanes[6];
+};
+
+
+} // namespace filament
+
+#endif // TNT_FILAMENT_FRUSTUM_H