Remove PowerScaledCoordinates and rename PowerScaledSphere to Sphere (closes #4)

src/util/sphere.cpp

@@ -0,0 +1,206 @@
+/*****************************************************************************************
+ *                                                                                       *
+ * OpenSpace                                                                             *
+ *                                                                                       *
+ * Copyright (c) 2014-2019                                                               *
+ *                                                                                       *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
+ * software and associated documentation files (the "Software"), to deal in the Software *
+ * without restriction, including without limitation the rights to use, copy, modify,    *
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
+ * permit persons to whom the Software is furnished to do so, subject to the following   *
+ * conditions:                                                                           *
+ *                                                                                       *
+ * The above copyright notice and this permission notice shall be included in all copies *
+ * or substantial portions of the Software.                                              *
+ *                                                                                       *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
+ ****************************************************************************************/
+
+#include <openspace/util/sphere.h>
+
+#include <ghoul/logging/logmanager.h>
+#include <cstring>
+
+namespace {
+    constexpr const char* _loggerCat = "PowerScaledSphere";
+} // namespace
+
+namespace openspace {
+
+Sphere::Sphere(float radius, int segments)
+    : Sphere(glm::vec3(radius), segments)
+{}
+
+// Alternative Constructor for using accurate triaxial ellipsoid
+Sphere::Sphere(glm::vec3 radius, int segments)
+    : _isize(6 * segments * segments)
+    , _vsize((segments + 1) * (segments + 1))
+    , _varray(new Vertex[_vsize])
+    , _iarray(new int[_isize])
+{
+    int nr = 0;
+    const float fsegments = static_cast<float>(segments);
+
+    for (int i = 0; i <= segments; i++) {
+        // define an extra vertex around the y-axis due to texture mapping
+        for (int j = 0; j <= segments; j++) {
+            const float fi = static_cast<float>(i);
+            const float fj = static_cast<float>(j);
+            // inclination angle (north to south)
+            const float theta = fi * glm::pi<float>() / fsegments;  // 0 -> PI
+            // azimuth angle (east to west)
+            const float phi = fj * glm::pi<float>() * 2.f / fsegments;  // 0 -> 2*PI
+
+            // Spherical coordinates based on ISO standard.
+            // https://en.wikipedia.org/wiki/Spherical_coordinate_system
+
+            const float x = radius[0] * sin(theta) * cos(phi);
+            const float y = radius[1] * sin(theta) * sin(phi);
+            const float z = radius[2] * cos(theta); // Z points towards pole (theta = 0)
+
+            _varray[nr].location[0] = x;
+            _varray[nr].location[1] = y;
+            _varray[nr].location[2] = z;
+            _varray[nr].location[3] = 0.0;
+
+            glm::vec3 normal = glm::vec3(x, y, z);
+            if (!(x == 0.f && y == 0.f && z == 0.f)) {
+                normal = glm::normalize(normal);
+            }
+
+            _varray[nr].normal[0] = normal[0];
+            _varray[nr].normal[1] = normal[1];
+            _varray[nr].normal[2] = normal[2];
+
+            const float t1 = fj / fsegments;
+            const float t2 = 1.f - (fi / fsegments);
+
+            _varray[nr].tex[0] = t1;
+            _varray[nr].tex[1] = t2;
+            ++nr;
+        }
+    }
+
+    nr = 0;
+    // define indices for all triangles
+    for (int i = 1; i <= segments; ++i) {
+        for (int j = 0; j < segments; ++j) {
+            const int t = segments + 1;
+            _iarray[nr] = t * (i - 1) + j + 0; //1
+            ++nr;
+            _iarray[nr] = t * (i + 0) + j + 0; //2
+            ++nr;
+            _iarray[nr] = t * (i + 0) + j + 1; //3
+            ++nr;
+
+            _iarray[nr] = t * (i - 1) + j + 0; //4
+            ++nr;
+            _iarray[nr] = t * (i + 0) + j + 1; //5
+            ++nr;
+            _iarray[nr] = t * (i - 1) + j + 1; //6
+            ++nr;
+        }
+    }
+}
+
+Sphere::Sphere(const Sphere& cpy)
+    : _vaoID(cpy._vaoID)
+    , _vBufferID(cpy._vBufferID)
+    , _iBufferID(cpy._iBufferID)
+    , _isize(cpy._isize)
+    , _vsize(cpy._vsize)
+    , _varray(new Vertex[_vsize])
+    , _iarray(new int[_isize])
+{
+    // @TODO This needs to be tested ---abock
+
+    std::memcpy(_varray, cpy._varray, _vsize * sizeof(Vertex));
+    std::memcpy(_iarray, cpy._iarray, _isize * sizeof(int));
+}
+
+Sphere::~Sphere() {
+    delete[] _varray;
+    delete[] _iarray;
+
+    _varray = nullptr;
+    _iarray = nullptr;
+
+    glDeleteBuffers(1, &_vBufferID);
+    glDeleteBuffers(1, &_iBufferID);
+    glDeleteVertexArrays(1, &_vaoID);
+}
+
+bool Sphere::initialize() {
+    // Initialize and upload to graphics card
+    if (_vaoID == 0) {
+        glGenVertexArrays(1, &_vaoID);
+    }
+
+    if (_vBufferID == 0) {
+        glGenBuffers(1, &_vBufferID);
+
+        if (_vBufferID == 0) {
+            LERROR("Could not create vertex buffer");
+            return false;
+        }
+    }
+
+    if (_iBufferID == 0) {
+        glGenBuffers(1, &_iBufferID);
+
+        if (_iBufferID == 0) {
+            LERROR("Could not create index buffer");
+            return false;
+        }
+    }
+
+    // First VAO setup
+    glBindVertexArray(_vaoID);
+
+    glBindBuffer(GL_ARRAY_BUFFER, _vBufferID);
+    glBufferData(GL_ARRAY_BUFFER, _vsize * sizeof(Vertex), _varray, GL_STATIC_DRAW);
+
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(Vertex), nullptr);
+
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(
+        1,
+        2,
+        GL_FLOAT,
+        GL_FALSE,
+        sizeof(Vertex),
+        reinterpret_cast<const GLvoid*>(offsetof(Vertex, tex)) // NOLINT
+    );
+
+    glEnableVertexAttribArray(2);
+    glVertexAttribPointer(
+        2,
+        3,
+        GL_FLOAT,
+        GL_FALSE,
+        sizeof(Vertex),
+        reinterpret_cast<const GLvoid*>(offsetof(Vertex, normal)) // NOLINT
+    );
+
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _iBufferID);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, _isize * sizeof(int), _iarray, GL_STATIC_DRAW);
+
+    glBindVertexArray(0);
+    return true;
+}
+
+void Sphere::render() {
+    glBindVertexArray(_vaoID);  // select first VAO
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _iBufferID);
+    glDrawElements(GL_TRIANGLES, _isize, GL_UNSIGNED_INT, nullptr);
+    glBindVertexArray(0);
+}
+
+}  // namespace openspace