OpenSubdiv/opensubdiv/osd/cpuGLVertexBuffer.cpp
David G Yu f3f28995a5 Enabled internal GL API loader as GLEW alternative
At build time, the preprocessor symbols: OSD_USES_GLEW or
OSD_USES_INTERNAL_GLAPILOADER determine the GL API loader
that will be used by the OSD library.
2020-03-06 11:37:55 -08:00

124 lines
3.2 KiB
C++

//
// Copyright 2013 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
// names, trademarks, service marks, or product names of the Licensor
// and its affiliates, except as required to comply with Section 4(c) of
// the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
#include "glLoader.h"
#include "../osd/cpuGLVertexBuffer.h"
#include <string.h>
namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {
namespace Osd {
CpuGLVertexBuffer::CpuGLVertexBuffer(int numElements, int numVertices)
: _numElements(numElements), _numVertices(numVertices),
_vbo(0), _cpuBuffer(0), _dataDirty(true) {
// Initialize internal OpenGL loader library if necessary
OpenSubdiv::internal::GLLoader::libraryInitializeGL();
}
CpuGLVertexBuffer::~CpuGLVertexBuffer() {
delete[] _cpuBuffer;
if (_vbo) {
glDeleteBuffers(1, &_vbo);
}
}
CpuGLVertexBuffer *
CpuGLVertexBuffer::Create(int numElements, int numVertices, void *) {
CpuGLVertexBuffer *instance =
new CpuGLVertexBuffer(numElements, numVertices);
if (instance->allocate()) return instance;
delete instance;
return NULL;
}
void
CpuGLVertexBuffer::UpdateData(const float *src,
int startVertex, int numVertices,
void * /*deviceContext*/) {
memcpy(_cpuBuffer + startVertex * GetNumElements(), src,
GetNumElements() * numVertices * sizeof(float));
_dataDirty = true;
}
int
CpuGLVertexBuffer::GetNumElements() const {
return _numElements;
}
int
CpuGLVertexBuffer::GetNumVertices() const {
return _numVertices;
}
float*
CpuGLVertexBuffer::BindCpuBuffer() {
_dataDirty = true; // caller might modify data
return _cpuBuffer;
}
GLuint
CpuGLVertexBuffer::BindVBO(void * /*deviceContext*/) {
if (! _dataDirty)
return _vbo;
int size = GetNumElements() * GetNumVertices() * sizeof(float);
if (! _vbo) {
glGenBuffers(1, &_vbo);
}
glBindBuffer(GL_ARRAY_BUFFER, _vbo);
glBufferData(GL_ARRAY_BUFFER, size, _cpuBuffer, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
_dataDirty = false;
return _vbo;
}
bool
CpuGLVertexBuffer::allocate() {
_cpuBuffer = new float[GetNumElements() * GetNumVertices()];
_dataDirty = true;
return true;
}
} // end namespace Osd
} // end namespace OPENSUBDIV_VERSION
} // end namespace OpenSubdiv