NazaraEngine/src/Nazara/Renderer/OcclusionQuery.cpp

103 lines
1.9 KiB
C++

// Copyright (C) 2012 Jérôme Leclercq
// This file is part of the "Nazara Engine".
// For conditions of distribution and use, see copyright notice in Config.hpp
#include <Nazara/Renderer/OpenGL.hpp>
#include <Nazara/Renderer/OcclusionQuery.hpp>
#include <Nazara/Core/Error.hpp>
#include <Nazara/Renderer/Config.hpp>
#include <Nazara/Renderer/Context.hpp>
#include <Nazara/Renderer/Renderer.hpp>
#include <stdexcept>
#include <Nazara/Renderer/Debug.hpp>
NzOcclusionQuery::NzOcclusionQuery() :
m_id(0)
{
#if NAZARA_RENDERER_SAFE
if (IsSupported())
{
#endif
NzContext::EnsureContext();
glGenQueries(1, reinterpret_cast<GLuint*>(&m_id));
#if NAZARA_RENDERER_SAFE
}
else
{
NazaraError("Occlusion queries not supported");
return;
}
#endif
#ifdef NAZARA_DEBUG
if (!m_id)
{
NazaraError("Failed to create occlusion query");
throw std::runtime_error("Constructor failed");
}
#endif
}
NzOcclusionQuery::~NzOcclusionQuery()
{
if (m_id)
{
NzContext::EnsureContext();
GLuint query = static_cast<GLuint>(m_id);
glDeleteQueries(1, &query);
}
}
void NzOcclusionQuery::Begin()
{
#ifdef NAZARA_DEBUG
if (NzContext::GetCurrent() == nullptr)
{
NazaraError("No active context");
return;
}
#endif
glBeginQuery(GL_SAMPLES_PASSED, m_id);
}
void NzOcclusionQuery::End()
{
#ifdef NAZARA_DEBUG
if (NzContext::GetCurrent() == nullptr)
{
NazaraError("No active context");
return;
}
#endif
glEndQuery(GL_SAMPLES_PASSED);
}
unsigned int NzOcclusionQuery::GetResult() const
{
NzContext::EnsureContext();
GLuint result;
glGetQueryObjectuiv(m_id, GL_QUERY_RESULT, &result);
return result;
}
bool NzOcclusionQuery::IsResultAvailable() const
{
NzContext::EnsureContext();
GLint available;
glGetQueryObjectiv(m_id, GL_QUERY_RESULT_AVAILABLE, &available);
return available == GL_TRUE;
}
bool NzOcclusionQuery::IsSupported()
{
return NazaraRenderer->HasCapability(nzRendererCap_OcclusionQuery);
}