// Copyright (C) 2009-2015, Panagiotis Christopoulos Charitos.
// All rights reserved.
// Code licensed under the BSD License.
// http://www.anki3d.org/LICENSE

#include "anki/renderer/Renderer.h"
#include "anki/scene/Camera.h"
#include "anki/scene/SceneGraph.h"
#include "anki/core/Counters.h"
#include "anki/misc/ConfigSet.h"

#include "anki/renderer/Ms.h"
#include "anki/renderer/Is.h"
#include "anki/renderer/Pps.h"
#include "anki/renderer/Fs.h"
#include "anki/renderer/Lf.h"
#include "anki/renderer/Dbg.h"
#include "anki/renderer/Tiler.h"

namespace anki {

//==============================================================================
Renderer::Renderer()
	: m_sceneDrawer(this)
{}

//==============================================================================
Renderer::~Renderer()
{}

//==============================================================================
Error Renderer::init(
	ThreadPool* threadpool,
	ResourceManager* resources,
	GrManager* gl,
	HeapAllocator<U8> alloc,
	StackAllocator<U8> frameAlloc,
	const ConfigSet& config,
	const Timestamp* globalTimestamp,
	TexturePtr reflections)
{
	m_globalTimestamp = globalTimestamp;
	m_threadpool = threadpool;
	m_resources = resources;
	m_gr = gl;
	m_alloc = alloc;
	m_frameAlloc = frameAlloc;
	m_reflectionsCubemapArr = reflections;

	Error err = initInternal(config);
	if(err)
	{
		ANKI_LOGE("Failed to initialize the renderer");
	}

	return err;
}

//==============================================================================
Error Renderer::initInternal(const ConfigSet& config)
{
	// Set from the config
	m_width = getAlignedRoundDown(TILE_SIZE, U(config.getNumber("width")));
	m_height = getAlignedRoundDown(TILE_SIZE, U(config.getNumber("height")));
	m_lodDistance = config.getNumber("lodDistance");
	m_framesNum = 0;
	m_samples = config.getNumber("samples");
	m_tileCountXY.x() = m_width / TILE_SIZE;
	m_tileCountXY.y() = m_height / TILE_SIZE;
	m_tileCount = m_tileCountXY.x() * m_tileCountXY.y();

	m_clusterer.init(getAllocator(), m_tileCountXY.x(), m_tileCountXY.y(),
		config.getNumber("clusterSizeZ"));

	m_tessellation = config.getNumber("tessellation");

	// A few sanity checks
	if(m_samples != 1 && m_samples != 4 && m_samples != 8 && m_samples != 16
		&& m_samples != 32)
	{
		ANKI_LOGE("Incorrect samples");
		return ErrorCode::USER_DATA;
	}

	if(m_width < 10 || m_height < 10)
	{
		ANKI_LOGE("Incorrect sizes");
		return ErrorCode::USER_DATA;
	}

	if(m_width % m_tileCountXY.x() != 0)
	{
		ANKI_LOGE("Width is not multiple of tile width");
		return ErrorCode::USER_DATA;
	}

	if(m_height % m_tileCountXY.y() != 0)
	{
		ANKI_LOGE("Height is not multiple of tile height");
		return ErrorCode::USER_DATA;
	}

	// quad setup
	ANKI_CHECK(
		m_resources->loadResource("shaders/Quad.vert.glsl", m_drawQuadVert));

	// Init the stages. Careful with the order!!!!!!!!!!
	m_ms.reset(m_alloc.newInstance<Ms>(this));
	ANKI_CHECK(m_ms->init(config));

	m_tiler.reset(m_alloc.newInstance<Tiler>(this));
	ANKI_CHECK(m_tiler->init());

	m_is.reset(m_alloc.newInstance<Is>(this));
	ANKI_CHECK(m_is->init(config));

	m_fs.reset(m_alloc.newInstance<Fs>(this));
	ANKI_CHECK(m_fs->init(config));

	m_lf.reset(m_alloc.newInstance<Lf>(this));
	ANKI_CHECK(m_lf->init(config));

	m_pps.reset(m_alloc.newInstance<Pps>(this));
	ANKI_CHECK(m_pps->init(config));

	m_dbg.reset(m_alloc.newInstance<Dbg>(this));
	ANKI_CHECK(m_dbg->init(config));

	return ErrorCode::NONE;
}

//==============================================================================
Error Renderer::render(SceneNode& frustumableNode, U frustumIdx,
	Array<CommandBufferPtr, RENDERER_COMMAND_BUFFERS_COUNT>& cmdb)
{
	m_frc = nullptr;
	Error err = frustumableNode.iterateComponentsOfType<FrustumComponent>(
		[&](FrustumComponent& frc) -> Error
	{
		if(frustumIdx == 0)
		{
			m_frc = &frc;
		}
		else
		{
			--frustumIdx;
		}

		return ErrorCode::NONE;
	});
	(void)err;
	ANKI_ASSERT(m_frc && "Not enough frustum components");

	m_frameAlloc.getMemoryPool().reset();

	// Calc a few vars
	//
	if(m_frc->getProjectionParameters() != m_projectionParams)
	{
		m_projectionParams = m_frc->getProjectionParameters();
		m_projectionParamsUpdateTimestamp = getGlobalTimestamp();
	}

	ANKI_ASSERT(m_frc->getFrustum().getType() == Frustum::Type::PERSPECTIVE);
	m_clusterer.prepare(getThreadPool(), frustumableNode);

	ANKI_COUNTER_START_TIMER(RENDERER_MS_TIME);
	ANKI_CHECK(m_ms->run(cmdb[0]));
	ANKI_COUNTER_STOP_TIMER_INC(RENDERER_MS_TIME);

	m_lf->runOcclusionTests(cmdb[0]);

	m_ms->generateMipmaps(cmdb[0]);

	m_tiler->run(cmdb[0]);

	ANKI_COUNTER_START_TIMER(RENDERER_IS_TIME);
	ANKI_CHECK(m_is->run(cmdb[1]));
	ANKI_COUNTER_STOP_TIMER_INC(RENDERER_IS_TIME);

	ANKI_CHECK(m_fs->run(cmdb[1]));
	m_lf->run(cmdb[1]);

	ANKI_COUNTER_START_TIMER(RENDERER_PPS_TIME);
	if(m_pps->getEnabled())
	{
		m_pps->run(cmdb[1]);
	}
	ANKI_COUNTER_STOP_TIMER_INC(RENDERER_PPS_TIME);

	if(m_dbg->getEnabled())
	{
		ANKI_CHECK(m_dbg->run(cmdb[1]));
	}

	++m_framesNum;

	return ErrorCode::NONE;
}

//==============================================================================
Vec3 Renderer::unproject(const Vec3& windowCoords, const Mat4& modelViewMat,
	const Mat4& projectionMat, const int view[4])
{
	Mat4 invPm = projectionMat * modelViewMat;
	invPm.invert();

	// the vec is in NDC space meaning: -1<=vec.x<=1 -1<=vec.y<=1 -1<=vec.z<=1
	Vec4 vec;
	vec.x() = (2.0 * (windowCoords.x() - view[0])) / view[2] - 1.0;
	vec.y() = (2.0 * (windowCoords.y() - view[1])) / view[3] - 1.0;
	vec.z() = 2.0 * windowCoords.z() - 1.0;
	vec.w() = 1.0;

	Vec4 out = invPm * vec;
	out /= out.w();
	return out.xyz();
}

//==============================================================================
void Renderer::createRenderTarget(U32 w, U32 h, const PixelFormat& format,
	U32 samples, SamplingFilter filter, U mipsCount, TexturePtr& rt)
{
	// Not very important but keep the resolution of render targets aligned to
	// 16
	if(0)
	{
		ANKI_ASSERT(isAligned(16, w));
		ANKI_ASSERT(isAligned(16, h));
	}

	TextureInitializer init;

	init.m_width = w;
	init.m_height = h;
	init.m_depth = 0;
	init.m_type = TextureType::_2D;
	init.m_format = format;
	init.m_mipmapsCount = mipsCount;
	init.m_samples = samples;
	init.m_sampling.m_minMagFilter = filter;
	if(mipsCount > 1)
	{
		init.m_sampling.m_mipmapFilter = filter;
	}
	else
	{
		init.m_sampling.m_mipmapFilter = SamplingFilter::BASE;
	}
	init.m_sampling.m_repeat = false;
	init.m_sampling.m_anisotropyLevel = 0;

	rt = m_gr->newInstance<Texture>(init);
}

//==============================================================================
void Renderer::createDrawQuadPipeline(
	ShaderPtr frag, const ColorStateInfo& colorState,
	PipelinePtr& ppline)
{
	PipelineInitializer init;

	init.m_inputAssembler.m_topology = PrimitiveTopology::TRIANGLE_STRIP;

	init.m_depthStencil.m_depthWriteEnabled = false;
	init.m_depthStencil.m_depthCompareFunction = CompareOperation::ALWAYS;

	init.m_color = colorState;

	init.m_shaders[U(ShaderType::VERTEX)] = m_drawQuadVert->getGrShader();
	init.m_shaders[U(ShaderType::FRAGMENT)] = frag;
	ppline = m_gr->newInstance<Pipeline>(init);
}

//==============================================================================
void Renderer::prepareForVisibilityTests(const SceneNode& cam)
{
	m_tiler->prepareForVisibilityTests(cam);
}

//==============================================================================
Bool Renderer::doGpuVisibilityTest(const CollisionShape& cs,
	const Aabb& aabb) const
{
	return m_tiler->test(cs, aabb);
}

} // end namespace anki