WIP BSP Tree for 3D Layer Sorting

cc/output/bsp_tree_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "cc/base/scoped_ptr_deque.h"
+#include "cc/base/scoped_ptr_vector.h"
+#include "cc/output/bsp_tree.h"
+#include "cc/output/bsp_walk_action.h"
+#include "cc/quads/draw_polygon.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+#define EXPECT_SORTED_LISTS_EQ(polygon_list, compare_list)        \
+  do {                                                            \
+    EXPECT_EQ(polygon_list.size(), compare_list.size());          \
+    for (unsigned int i = 0; i < polygon_list.size(); i++) {      \
+      EXPECT_EQ(polygon_list[i]->order_index(), compare_list[i]); \
+    }                                                             \
+  } while (false);
+
+#define INT_VECTOR_FROM_ARRAY(array) \
+  std::vector<int>(array, array + arraysize(array))
+
+#define CREATE_DRAW_POLYGON(vertex_vector, normal, polygon_id) \
+  new DrawPolygon(NULL, vertex_vector, normal, polygon_id)
+
+class BspTreeTest {
+ public:
+  static void RunTest(ScopedPtrDeque<DrawPolygon>* test_polygons,
+                      const std::vector<int>& compare_list) {
+    BspTree bsp_tree(test_polygons);
+
+    std::vector<DrawPolygon*> sorted_list;
+    BspWalkActionToVector action_handler(&sorted_list);
+    bsp_tree.TraverseWithActionHandler(&action_handler);
+
+    EXPECT_SORTED_LISTS_EQ(sorted_list, compare_list);
+    EXPECT_TRUE(VerifySidedness(bsp_tree.root()));
+  }
+
+  static bool VerifySidedness(const scoped_ptr<BspNode>& node) {
+    // We check if both the front and back child nodes have geometry that is
+    // completely on the expected side of the current node.
+    bool front_ok = true;
+    bool back_ok = true;
+    if (node->back_child) {
+      // Make sure the back child lies entirely behind this node.
+      BspCompareResult result = DrawPolygon::SideCompare(
+          *(node->back_child->node_data), *(node->node_data));
+      if (result != BSP_BACK) {
+        return false;
+      }
+      back_ok = VerifySidedness(node->back_child);
+    }
+    // Make sure the front child lies entirely in front of this node.
+    if (node->front_child) {
+      BspCompareResult result = DrawPolygon::SideCompare(
+          *(node->front_child->node_data), *(node->node_data));
+      if (result != BSP_FRONT) {
+        return false;
+      }
+      front_ok = VerifySidedness(node->front_child);
+    }
+    if (!back_ok || !front_ok) {
+      return false;
+    }
+
+    // Now we need to make sure our coplanar geometry is all actually coplanar.
+    for (size_t i = 0; i < node->coplanars_front.size(); i++) {
+      BspCompareResult result = DrawPolygon::SideCompare(
+          *(node->coplanars_front[i]), *(node->node_data));
+      if (result != BSP_COPLANAR_FRONT) {
+        return false;
+      }
+    }
+    for (size_t i = 0; i < node->coplanars_back.size(); i++) {
+      BspCompareResult result = DrawPolygon::SideCompare(
+          *(node->coplanars_back[i]), *(node->node_data));
+      if (result != BSP_COPLANAR_BACK) {
+        return false;
+      }
+    }
+    return true;
+  }
+};
+
+// Simple standing quads all parallel with each other, causing no splits.
+TEST(BspTreeTest, NoSplit) {
+  std::vector<gfx::Point3F> vertices_a;
+  vertices_a.push_back(gfx::Point3F(0.0f, 10.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(0.0f, 0.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(10.0f, 0.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(10.0f, 10.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_b;
+  vertices_b.push_back(gfx::Point3F(0.0f, 10.0f, -5.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, 0.0f, -5.0f));
+  vertices_b.push_back(gfx::Point3F(10.0f, 0.0f, -5.0f));
+  vertices_b.push_back(gfx::Point3F(10.0f, 10.0f, -5.0f));
+  std::vector<gfx::Point3F> vertices_c;
+  vertices_c.push_back(gfx::Point3F(0.0f, 10.0f, 5.0f));
+  vertices_c.push_back(gfx::Point3F(0.0f, 0.0f, 5.0f));
+  vertices_c.push_back(gfx::Point3F(10.0f, 0.0f, 5.0f));
+  vertices_c.push_back(gfx::Point3F(10.0f, 10.0f, 5.0f));
+
+  scoped_ptr<DrawPolygon> polygon_a(
+      CREATE_DRAW_POLYGON(vertices_a, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 0));
+  scoped_ptr<DrawPolygon> polygon_b(
+      CREATE_DRAW_POLYGON(vertices_b, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 1));
+  scoped_ptr<DrawPolygon> polygon_c(
+      CREATE_DRAW_POLYGON(vertices_c, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 2));
+
+  ScopedPtrDeque<DrawPolygon> polygon_list;
+  polygon_list.push_back(polygon_a.Pass());
+  polygon_list.push_back(polygon_b.Pass());
+  polygon_list.push_back(polygon_c.Pass());
+
+  int compare_ids[] = {1, 0, 2};
+  std::vector<int> compare_list = INT_VECTOR_FROM_ARRAY(compare_ids);
+  BspTreeTest::RunTest(&polygon_list, compare_list);
+}
+
+// Basic two polygon split, can be viewed as a + from above.
+TEST(BspTreeTest, BasicSplit) {
+  std::vector<gfx::Point3F> vertices_a;
+  vertices_a.push_back(gfx::Point3F(-5.0f, -5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(-5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, -5.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_b;
+  vertices_b.push_back(gfx::Point3F(0.0f, -5.0f, -5.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, 5.0f, -5.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, 5.0f, 5.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, -5.0f, 5.0f));
+
+  scoped_ptr<DrawPolygon> polygon_a(
+      CREATE_DRAW_POLYGON(vertices_a, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 0));
+  scoped_ptr<DrawPolygon> polygon_b(
+      CREATE_DRAW_POLYGON(vertices_b, gfx::Vector3dF(-1.0f, 0.0f, 0.0f), 1));
+
+  ScopedPtrDeque<DrawPolygon> polygon_list;
+  polygon_list.push_back(polygon_a.Pass());
+  polygon_list.push_back(polygon_b.Pass());
+
+  int compare_ids[] = {1, 0, 1};
+  std::vector<int> compare_list = INT_VECTOR_FROM_ARRAY(compare_ids);
+  BspTreeTest::RunTest(&polygon_list, compare_list);
+}
+
+// Same as above with the second quad offset so it doesn't intersect. One quad
+// should be very clearly on one side of the other, and no splitting should
+// occur.
+TEST(BspTreeTest, QuadOffset) {
+  std::vector<gfx::Point3F> vertices_a;
+  vertices_a.push_back(gfx::Point3F(-5.0f, -5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(-5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, -5.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_b;
+  vertices_b.push_back(gfx::Point3F(0.0f, 5.0f, -15.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, -5.0f, -15.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, -5.0f, -10.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, 5.0f, -10.0f));
+
+  scoped_ptr<DrawPolygon> polygon_a(
+      CREATE_DRAW_POLYGON(vertices_a, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 0));
+  scoped_ptr<DrawPolygon> polygon_b(
+      CREATE_DRAW_POLYGON(vertices_b, gfx::Vector3dF(-1.0f, 0.0f, 0.0f), 1));
+
+  ScopedPtrDeque<DrawPolygon> polygon_list;
+  polygon_list.push_back(polygon_a.Pass());
+  polygon_list.push_back(polygon_b.Pass());
+
+  int compare_ids[] = {1, 0};
+  std::vector<int> compare_list = INT_VECTOR_FROM_ARRAY(compare_ids);
+  BspTreeTest::RunTest(&polygon_list, compare_list);
+}
+
+// Same as above, but this time we change the order in which the quads are
+// inserted into the tree, causing one to actually cross the plane of the other
+// and cause a split.
+TEST(BspTreeTest, QuadOffsetSplit) {
+  std::vector<gfx::Point3F> vertices_a;
+  vertices_a.push_back(gfx::Point3F(-5.0f, -5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(-5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, -5.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_b;
+  vertices_b.push_back(gfx::Point3F(0.0f, -5.0f, -15.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, 5.0f, -15.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, 5.0f, -10.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, -5.0f, -10.0f));
+
+  scoped_ptr<DrawPolygon> polygon_a(
+      CREATE_DRAW_POLYGON(vertices_a, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 0));
+  scoped_ptr<DrawPolygon> polygon_b(
+      CREATE_DRAW_POLYGON(vertices_b, gfx::Vector3dF(-1.0f, 0.0f, 0.0f), 1));
+
+  ScopedPtrDeque<DrawPolygon> polygon_list;
+  polygon_list.push_back(polygon_b.Pass());
+  polygon_list.push_back(polygon_a.Pass());
+
+  int compare_ids[] = {0, 1, 0};
+  std::vector<int> compare_list = INT_VECTOR_FROM_ARRAY(compare_ids);
+  BspTreeTest::RunTest(&polygon_list, compare_list);
+}
+
+// In addition to what can be viewed as a + from above, another piece of
+// geometry is inserted to cut these pieces right in the middle, viewed as
+// a quad from overhead.
+TEST(BspTreeTest, ThreeWaySplit) {
+  std::vector<gfx::Point3F> vertices_a;
+  vertices_a.push_back(gfx::Point3F(-5.0f, -5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(-5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, -5.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_b;
+  vertices_b.push_back(gfx::Point3F(0.0f, -5.0f, -5.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, 5.0f, -5.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, 5.0f, 5.0f));
+  vertices_b.push_back(gfx::Point3F(0.0f, -5.0f, 5.0f));
+  std::vector<gfx::Point3F> vertices_c;
+  vertices_c.push_back(gfx::Point3F(-5.0f, 0.0f, -5.0f));
+  vertices_c.push_back(gfx::Point3F(-5.0f, 0.0f, 5.0f));
+  vertices_c.push_back(gfx::Point3F(5.0f, 0.0f, 5.0f));
+  vertices_c.push_back(gfx::Point3F(5.0f, 0.0f, -5.0f));
+
+  scoped_ptr<DrawPolygon> polygon_a(
+      CREATE_DRAW_POLYGON(vertices_a, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 0));
+  scoped_ptr<DrawPolygon> polygon_b(
+      CREATE_DRAW_POLYGON(vertices_b, gfx::Vector3dF(-1.0f, 0.0f, 0.0f), 1));
+  scoped_ptr<DrawPolygon> polygon_c(
+      CREATE_DRAW_POLYGON(vertices_c, gfx::Vector3dF(0.0f, 1.0f, 0.0f), 2));
+
+  ScopedPtrDeque<DrawPolygon> polygon_list;
+  polygon_list.push_back(polygon_a.Pass());
+  polygon_list.push_back(polygon_b.Pass());
+  polygon_list.push_back(polygon_c.Pass());
+
+  int compare_ids[] = {2, 1, 2, 0, 2, 1, 2};
+  std::vector<int> compare_list = INT_VECTOR_FROM_ARRAY(compare_ids);
+  BspTreeTest::RunTest(&polygon_list, compare_list);
+}
+
+// This test checks whether coplanar geometry, when inserted into the tree in
+// order, comes back in the same order as it should.
+TEST(BspTreeTest, Coplanar) {
+  std::vector<gfx::Point3F> vertices_a;
+  vertices_a.push_back(gfx::Point3F(-5.0f, -5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(-5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, -5.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_b;
+  vertices_b.push_back(gfx::Point3F(-4.0f, -4.0f, 0.0f));
+  vertices_b.push_back(gfx::Point3F(-4.0f, 4.0f, 0.0f));
+  vertices_b.push_back(gfx::Point3F(4.0f, 4.0f, 0.0f));
+  vertices_b.push_back(gfx::Point3F(4.0f, -4.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_c;
+  vertices_c.push_back(gfx::Point3F(-3.0f, -3.0f, 0.0f));
+  vertices_c.push_back(gfx::Point3F(-3.0f, 3.0f, 0.0f));
+  vertices_c.push_back(gfx::Point3F(3.0f, 3.0f, 0.0f));
+  vertices_c.push_back(gfx::Point3F(3.0f, -3.0f, 0.0f));
+
+  scoped_ptr<DrawPolygon> polygon_a(
+      CREATE_DRAW_POLYGON(vertices_a, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 0));
+  scoped_ptr<DrawPolygon> polygon_b(
+      CREATE_DRAW_POLYGON(vertices_b, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 1));
+  scoped_ptr<DrawPolygon> polygon_c(
+      CREATE_DRAW_POLYGON(vertices_c, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 2));
+
+  scoped_ptr<DrawPolygon> polygon_d = polygon_a->CreateCopy();
+  scoped_ptr<DrawPolygon> polygon_e = polygon_b->CreateCopy();
+  scoped_ptr<DrawPolygon> polygon_f = polygon_c->CreateCopy();
+
+  {
+    ScopedPtrDeque<DrawPolygon> polygon_list;
+    polygon_list.push_back(polygon_a.Pass());
+    polygon_list.push_back(polygon_b.Pass());
+    polygon_list.push_back(polygon_c.Pass());
+
+    int compare_ids[] = {0, 1, 2};
+    std::vector<int> compare_list = INT_VECTOR_FROM_ARRAY(compare_ids);
+    BspTreeTest::RunTest(&polygon_list, compare_list);
+  }
+
+  // Now check a different order and ensure we get that back as well
+  {
+    ScopedPtrDeque<DrawPolygon> polygon_list;
+    polygon_list.push_back(polygon_f.Pass());
+    polygon_list.push_back(polygon_d.Pass());
+    polygon_list.push_back(polygon_e.Pass());
+
+    int compare_ids[] = {0, 1, 2};
+    std::vector<int> compare_list = INT_VECTOR_FROM_ARRAY(compare_ids);
+    BspTreeTest::RunTest(&polygon_list, compare_list);
+  }
+}
+
+// A bunch of coplanar geometry should end up sharing a single node, and
+// result in the final piece of geometry splitting into just two pieces on
+// either side of the shared plane.
+TEST(BspTreeTest, CoplanarSplit) {
+  std::vector<gfx::Point3F> vertices_a;
+  vertices_a.push_back(gfx::Point3F(-5.0f, -5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(-5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, 5.0f, 0.0f));
+  vertices_a.push_back(gfx::Point3F(5.0f, -5.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_b;
+  vertices_b.push_back(gfx::Point3F(-4.0f, -4.0f, 0.0f));
+  vertices_b.push_back(gfx::Point3F(-4.0f, 4.0f, 0.0f));
+  vertices_b.push_back(gfx::Point3F(4.0f, 4.0f, 0.0f));
+  vertices_b.push_back(gfx::Point3F(4.0f, -4.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_c;
+  vertices_c.push_back(gfx::Point3F(-3.0f, -3.0f, 0.0f));
+  vertices_c.push_back(gfx::Point3F(-3.0f, 3.0f, 0.0f));
+  vertices_c.push_back(gfx::Point3F(3.0f, 3.0f, 0.0f));
+  vertices_c.push_back(gfx::Point3F(3.0f, -3.0f, 0.0f));
+  std::vector<gfx::Point3F> vertices_d;
+  vertices_d.push_back(gfx::Point3F(0.0f, -15.0f, -15.0f));
+  vertices_d.push_back(gfx::Point3F(0.0f, 15.0f, -15.0f));
+  vertices_d.push_back(gfx::Point3F(0.0f, 15.0f, 15.0f));
+  vertices_d.push_back(gfx::Point3F(0.0f, -15.0f, 15.0f));
+
+  scoped_ptr<DrawPolygon> polygon_a(
+      CREATE_DRAW_POLYGON(vertices_a, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 0));
+  scoped_ptr<DrawPolygon> polygon_b(
+      CREATE_DRAW_POLYGON(vertices_b, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 1));
+  scoped_ptr<DrawPolygon> polygon_c(
+      CREATE_DRAW_POLYGON(vertices_c, gfx::Vector3dF(0.0f, 0.0f, 1.0f), 2));
+  scoped_ptr<DrawPolygon> polygon_d(
+      CREATE_DRAW_POLYGON(vertices_d, gfx::Vector3dF(-1.0f, 0.0f, 0.0f), 3));
+
+  ScopedPtrDeque<DrawPolygon> polygon_list;
+  polygon_list.push_back(polygon_a.Pass());
+  polygon_list.push_back(polygon_b.Pass());
+  polygon_list.push_back(polygon_c.Pass());
+  polygon_list.push_back(polygon_d.Pass());
+
+  int compare_ids[] = {3, 0, 1, 2, 3};
+  std::vector<int> compare_list = INT_VECTOR_FROM_ARRAY(compare_ids);
+  BspTreeTest::RunTest(&polygon_list, compare_list);
+}
+
+}  // namespace
+}  // namespace cc