Commit 7a15454e authored by Philip Trettner's avatar Philip Trettner
parents 27681b36 82883478
MIT License
Copyright (c) 2017 Visual Computing Institute
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 "UVSphere.hh"
using namespace glow::geometry;
#pragma once
#include <glm/vec2.hpp>
#include <glm/vec3.hpp>
#include <glm/geometric.hpp>
#include <glm/common.hpp>
#include <glow/common/shared.hh>
#include <glow/objects/VertexArray.hh>
#include <glow/objects/ArrayBuffer.hh>
#include <glow/objects/ElementArrayBuffer.hh>
#include <fstream>
namespace glow
{
namespace geometry
{
/// Default type for Cube vertices
struct UVSphereVertex
{
glm::vec3 pos;
glm::vec3 normal;
glm::vec3 tangent;
glm::vec2 texCoord;
static std::vector<ArrayBufferAttribute> attributes()
{
return {
{&UVSphereVertex::pos, "aPosition"}, //
{&UVSphereVertex::normal, "aNormal"}, //
{&UVSphereVertex::tangent, "aTangent"}, //
{&UVSphereVertex::texCoord, "aTexCoord"},
};
}
};
/// Builder for a UVSphere
/// VertexT needs a c'tor that can be called with
/// (glm::vec3 position, glm::vec3 normal, glm::vec3 tangent, glm::vec2 texCoord)
///
/// Supported built-in types:
/// UVSphereVertex
///
/// If you use your custom vertex struct you have 2 options:
/// A: specify all attributes in UVSphere(...) ctor
/// B: implement the following function in your VertexT:
/// static std::vector<ArrayBufferAttribute> attributes();
template <typename VertexT = UVSphereVertex>
class UVSphere
{
public:
/// List of cube attributes
std::vector<ArrayBufferAttribute> attributes;
/// Number of segments
int32_t segments;
/// Number of rings
int32_t rings;
/// Sphere radius
float radius;
public: // default vertex creator
static VertexT createVertex(glm::vec3 position, glm::vec3 normal, glm::vec3 tangent, glm::vec2 texCoord)
{
return {position, normal, tangent, texCoord};
}
public:
UVSphere(std::vector<ArrayBufferAttribute> const& attrs = attributesOf((VertexT*)0),
int32_t segments = 32,
int32_t rings = 16,
float radius = 1.0f)
: attributes(attrs), segments(segments), rings(rings), radius(radius)
{
if (segments < 3)
{
this->segments = 3;
glow::info() << "Clamping sphere segments to 3.";
}
if (rings < 3)
{
this->rings = 3;
glow::info() << "Clamping sphere segments to 3.";
}
}
/**
* @brief generates a Vertex Array with AB and EAB
*/
template <typename VertexCreator = decltype(createVertex)>
SharedVertexArray generate(VertexCreator&& gen = createVertex) const
{
auto ab = ArrayBuffer::create();
auto eab = ElementArrayBuffer::create();
ab->defineAttributes(attributes);
// For texturing, we need a vertical cut and may not wrap around
std::vector<VertexT> vertices((rings + 1 ) * (segments + 1));
// rings * segments quads (each consisting of 2 * 3 vertices)
std::vector<uint32_t> indices(3 * (rings * segments * 2));
// Vertex attributes
auto vi = 0u;
for (int r = 0; r < rings + 1; ++r)
for (int s = 0; s < segments + 1; ++s)
{
float theta = M_PI / rings * r;
float phi = 2 * M_PI / segments * s;
glm::vec3 position = {std::cos(phi) * std::sin(theta) * radius, std::cos(theta) * radius, std::sin(phi) * std::sin(theta) * radius};
glm::vec3 normal = glm::normalize(position);
glm::vec3 tangent = {sin(phi), 0, cos(phi)};
glm::vec2 texcoord = {static_cast<float>(s) / segments, static_cast<float>(r) / rings};
vertices[vi++] = gen(position, normal, tangent, texcoord);
}
// Indices
auto ii = 0u;
for (int r = 0; r < rings; ++r)
for (int s = 0; s < segments; ++s)
{
uint32_t startIdxTop = (segments+1) * r;
uint32_t startIdxBot = (segments+1) * (r + 1);
indices[ii++] = startIdxTop + s;
indices[ii++] = startIdxTop + ((s + 1) );
indices[ii++] = startIdxBot + s;
indices[ii++] = startIdxBot + s;
indices[ii++] = startIdxTop + ((s + 1) );
indices[ii++] = startIdxBot + ((s + 1) );
}
ab->bind().setData(vertices);
eab->bind().setIndices(indices);
return VertexArray::create(ab, eab, GL_TRIANGLES);
}
public: // Predefined attributes
static std::vector<ArrayBufferAttribute> attributesOf(void*) { return VertexT::attributes(); }
};
}
}
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