Added the bulk of the algorithm for GPU accelerated 2D vector curve...

core/cross/gpu2d/path_cache.h

+/*
+ * Copyright 2010, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef O3D_CORE_CROSS_GPU2D_PATH_CACHE_H_
+#define O3D_CORE_CROSS_GPU2D_PATH_CACHE_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace o3d {
+namespace gpu2d {
+
+// A cache of the processed triangle mesh for a given path. Because
+// these might be expensive to allocate (using malloc/free
+// internally), it is recommended to try to reuse them when possible.
+
+// Uncomment the following to obtain debugging information for the edges facing
+// the interior region of the mesh.
+// #define O3D_CORE_CROSS_GPU2D_PATH_CACHE_DEBUG_INTERIOR_EDGES
+
+class PathCache {
+ public:
+  PathCache() {
+  }
+
+  // The number of vertices in the mesh.
+  unsigned int num_vertices() const;
+
+  // Get the base pointer to the vertex information. There are two
+  // coordinates per vertex. This pointer is valid until the cache is
+  // cleared or another vertex is added. Returns NULL if there are no
+  // vertices in the mesh.
+  const float* vertices() const;
+
+  // Get the base pointer to the texture coordinate information. There
+  // are three coordinates per vertex. This pointer is valid until the
+  // cache is cleared or another vertex is added. Returns NULL if
+  // there are no vertices in the mesh.
+  const float* texcoords() const;
+
+  // Adds a vertex's information to the cache. The first two arguments
+  // are the x and y coordinates of the vertex on the plane; the last
+  // three arguments are the cubic texture coordinates associated with
+  // this vertex.
+  void AddVertex(float x, float y,
+                 float k, float l, float m);
+
+  // The number of interior vertices.
+  unsigned int num_interior_vertices() const;
+  // Base pointer to the interior vertices; two coordinates per
+  // vertex, which can be drawn as GL_TRIANGLES. Returns NULL if there
+  // are no interior vertices in the mesh.
+  const float* interior_vertices() const;
+  // Adds an interior vertex to the cache.
+  void AddInteriorVertex(float x, float y);
+
+  // Clears all of the stored vertex information in this cache.
+  void Clear();
+
+#ifdef O3D_CORE_CROSS_GPU2D_PATH_CACHE_DEBUG_INTERIOR_EDGES
+  // The number of interior edge vertices
+  unsigned int num_interior_edge_vertices() const;
+  // Base pointer to the interior vertices; two coordinates per
+  // vertex, which can be drawn as GL_LINES. Returns NULL if there are
+  // no interior edge vertices in the mesh.
+  const float* interior_edge_vertices() const;
+  void AddInteriorEdgeVertex(float x, float y);
+#endif  // O3D_CORE_CROSS_GPU2D_PATH_CACHE_DEBUG_INTERIOR_EDGES
+
+ private:
+  // The two-dimensional vertices of the triangle mesh.
+  std::vector<float> vertices_;
+
+  // The three-dimensional cubic texture coordinates.
+  std::vector<float> texcoords_;
+
+  std::vector<float> interior_vertices_;
+
+#ifdef O3D_CORE_CROSS_GPU2D_PATH_CACHE_DEBUG_INTERIOR_EDGES
+  // The following is only for debugging
+  std::vector<float> interior_edge_vertices_;
+#endif  // O3D_CORE_CROSS_GPU2D_PATH_CACHE_DEBUG_INTERIOR_EDGES
+
+  DISALLOW_COPY_AND_ASSIGN(PathCache);
+};
+
+}  // namespace gpu2d
+}  // namespace o3d
+
+#endif  // O3D_CORE_CROSS_GPU2D_PATH_CACHE_H_
+