/******************************************************************************
 * Spine Runtimes License Agreement
 * Last updated January 1, 2020. Replaces all prior versions.
 *
 * Copyright (c) 2013-2020, Esoteric Software LLC
 *
 * Integration of the Spine Runtimes into software or otherwise creating
 * derivative works of the Spine Runtimes is permitted under the terms and
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 *
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 * or otherwise create derivative works of the Spine Runtimes (collectively,
 * "Products"), provided that each user of the Products must obtain their own
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#include <spine/spine-cocos2dx.h>
#if COCOS2D_VERSION >= 0x00040000

#include <spine/Extension.h>
#include <algorithm>

USING_NS_CC;
#define EVENT_AFTER_DRAW_RESET_POSITION "director_after_draw"
using std::max;
#define INITIAL_SIZE (10000)

#include "renderer/ccShaders.h"
#include "renderer/backend/Device.h"
#include "renderer/backend/Types.h"

namespace spine {

static SkeletonBatch* instance = nullptr;

SkeletonBatch* SkeletonBatch::getInstance () {
	if (!instance) instance = new SkeletonBatch();
	return instance;
}

void SkeletonBatch::destroyInstance () {
	if (instance) {
		delete instance;
		instance = nullptr;
	}
}

SkeletonBatch::SkeletonBatch () {

    auto program = backend::Program::getBuiltinProgram(backend::ProgramType::POSITION_TEXTURE_COLOR);
	_programState = new backend::ProgramState(program); // new default program state
    for (unsigned int i = 0; i < INITIAL_SIZE; i++) {
        _commandsPool.push_back(newCommand());
    }
    reset();
    // callback after drawing is finished so we can clear out the batch state
    // for the next frame
    Director::getInstance()->getEventDispatcher()->addCustomEventListener(EVENT_AFTER_DRAW_RESET_POSITION, [this](EventCustom* eventCustom) {
        this->update(0);
        });;
}

SkeletonBatch::~SkeletonBatch () {
	Director::getInstance()->getEventDispatcher()->removeCustomEventListeners(EVENT_AFTER_DRAW_RESET_POSITION);

	for (unsigned int i = 0; i < _commandsPool.size(); i++) {
        CC_SAFE_RELEASE(_commandsPool[i]->getPipelineDescriptor().programState);
		delete _commandsPool[i];
		_commandsPool[i] = nullptr;
	}
	CC_SAFE_RELEASE(_programState);
}

backend::ProgramState* SkeletonBatch::updateCommandPipelinePS(SkeletonCommand* command, backend::ProgramState* programState)
{
	auto& currentState = command->getPipelineDescriptor().programState;
#if defined(AXIS_VERSION)
	if(currentState == nullptr || currentState->getProgram() != programState->getProgram() || currentState->getUniformID() != programState->getUniformID()) {
#else
	if(currentState == nullptr || currentState->getProgram() != programState->getProgram()) {
#endif
		CC_SAFE_RELEASE(currentState);
		currentState = programState->clone();
		
		auto vertexLayout = currentState->getVertexLayout();
        auto locPosition  = currentState->getAttributeLocation(backend::ATTRIBUTE_NAME_POSITION);
        auto locTexcoord  = currentState->getAttributeLocation(backend::ATTRIBUTE_NAME_TEXCOORD);
        auto locColor     = currentState->getAttributeLocation(backend::ATTRIBUTE_NAME_COLOR);
		vertexLayout->setAttribute(backend::ATTRIBUTE_NAME_POSITION, locPosition, backend::VertexFormat::FLOAT3, offsetof(V3F_C4B_T2F, vertices), false);
		vertexLayout->setAttribute(backend::ATTRIBUTE_NAME_COLOR, locColor, backend::VertexFormat::UBYTE4, offsetof(V3F_C4B_T2F, colors), true);
		vertexLayout->setAttribute(backend::ATTRIBUTE_NAME_TEXCOORD, locTexcoord, backend::VertexFormat::FLOAT2, offsetof(V3F_C4B_T2F, texCoords), false);
		vertexLayout->setLayout(sizeof(_vertices[0]));


		command->_locMVP     = currentState->getUniformLocation(backend::UNIFORM_NAME_MVP_MATRIX);
        command->_locTexture = currentState->getUniformLocation(backend::UNIFORM_NAME_TEXTURE);
	}
	return currentState;
}

void SkeletonBatch::update (float delta) {
	reset();
}

cocos2d::V3F_C4B_T2F* SkeletonBatch::allocateVertices(uint32_t numVertices) {
	if (_vertices.size() - _numVertices < numVertices) {
		cocos2d::V3F_C4B_T2F* oldData = _vertices.data();
		_vertices.resize((_vertices.size() + numVertices) * 2 + 1);
		cocos2d::V3F_C4B_T2F* newData = _vertices.data();
		for (uint32_t i = 0; i < this->_nextFreeCommand; i++) {
			SkeletonCommand* command = _commandsPool[i];
			SkeletonCommand::Triangles& triangles = (SkeletonCommand::Triangles&)command->getTriangles();
			triangles.verts = newData + (triangles.verts - oldData);
		}
	}

	cocos2d::V3F_C4B_T2F* vertices = _vertices.data() + _numVertices;
	_numVertices += numVertices;
	return vertices;
}

void SkeletonBatch::deallocateVertices(uint32_t numVertices) {
	_numVertices -= numVertices;
}


unsigned short* SkeletonBatch::allocateIndices(uint32_t numIndices) {
	if (_indices.getCapacity() - _indices.size() < numIndices) {
		unsigned short* oldData = _indices.buffer();
		int oldSize = _indices.size();
		_indices.ensureCapacity(_indices.size() + numIndices);
		unsigned short* newData = _indices.buffer();
		for (uint32_t i = 0; i < this->_nextFreeCommand; i++) {
			SkeletonCommand* command = _commandsPool[i];
			SkeletonCommand::Triangles& triangles = (SkeletonCommand::Triangles&)command->getTriangles();
			if (triangles.indices >= oldData && triangles.indices < oldData + oldSize) {
				triangles.indices = newData + (triangles.indices - oldData);
			}
		}
	}

	unsigned short* indices = _indices.buffer() + _indices.size();
	_indices.setSize(_indices.size() + numIndices, 0);
	return indices;
}

void SkeletonBatch::deallocateIndices(uint32_t numIndices) {
	_indices.setSize(_indices.size() - numIndices, 0);
}


cocos2d::TrianglesCommand* SkeletonBatch::addCommand(cocos2d::Renderer* renderer, float globalOrder, cocos2d::Texture2D* texture, backend::ProgramState* programState, cocos2d::BlendFunc blendType, const cocos2d::TrianglesCommand::Triangles& triangles, const cocos2d::Mat4& mv, uint32_t flags) {
	SkeletonCommand* command = nextFreeCommand();
    const cocos2d::Mat4& projectionMat = Director::getInstance()->getMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_PROJECTION);    

	if (programState == nullptr)
		programState = _programState;

	CCASSERT(programState, "programState should not be null");

	auto pipelinePS = updateCommandPipelinePS(command, programState);
	
	pipelinePS->setUniform(command->_locMVP, projectionMat.m, sizeof(projectionMat.m));
	pipelinePS->setTexture(command->_locTexture, 0, texture->getBackendTexture());

	command->init(globalOrder, texture, blendType, triangles, mv, flags);
	renderer->addCommand(command);
	return command;
}

void SkeletonBatch::reset() {
	_nextFreeCommand = 0;
	_numVertices = 0;
	_indices.setSize(0, 0);
}

SkeletonCommand* SkeletonBatch::nextFreeCommand() {
    if (_commandsPool.size() <= _nextFreeCommand) {
        unsigned int newSize = _commandsPool.size() * 2 + 1;
        for (int i = _commandsPool.size(); i < newSize; i++) {
            _commandsPool.push_back(newCommand());
        }
    }
    auto* command = _commandsPool[_nextFreeCommand++];
    return command;
}

SkeletonCommand* SkeletonBatch::newCommand() {
    auto* command = new SkeletonCommand();
    return command;
}
}

#endif