/* This file is part of the Spring engine (GPL v2 or later), see LICENSE.html */


#include "SmokeProjectile2.h"

#include "Game/Camera.h"
#include "Game/GlobalUnsynced.h"
#include "Map/Ground.h"
#include "Rendering/GlobalRendering.h"
#include "Rendering/ProjectileDrawer.h"
#include "Rendering/GL/VertexArray.h"
#include "Rendering/Textures/TextureAtlas.h"
#include "Sim/Misc/Wind.h"

CR_BIND_DERIVED(CSmokeProjectile2, CProjectile, );

CR_REG_METADATA(CSmokeProjectile2,
(
	CR_MEMBER_BEGINFLAG(CM_Config),
		CR_MEMBER(color),
		CR_MEMBER(ageSpeed),
		CR_MEMBER(size),
		CR_MEMBER(startSize),
		CR_MEMBER(sizeExpansion),
		CR_MEMBER(wantedPos),
		CR_MEMBER(glowFalloff),
	CR_MEMBER_ENDFLAG(CM_Config),
	CR_MEMBER(age),
	CR_MEMBER(textureNum),
	CR_RESERVED(8)
));

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CSmokeProjectile2::CSmokeProjectile2():
	CProjectile(),
	color(0.5f),
	age(0.0f),
	ageSpeed(1.0f),
	size(0.0f),
	startSize(0.0f),
	sizeExpansion(0.0f),
	textureNum(0),
	glowFalloff(0.0f)
{
	deleteMe = false;
	checkCol = false;
}

CSmokeProjectile2::CSmokeProjectile2(
	CUnit* owner,
	const float3& pos,
	const float3& wantedPos,
	const float3& speed,
	float ttl,
	float startSize,
	float sizeExpansion,
	float color)
: CProjectile(pos, speed, owner, false, false, false),
	color(color),
	age(0),
	size(0),
	startSize(startSize),
	sizeExpansion(sizeExpansion),
	wantedPos(wantedPos)
{
	ageSpeed = 1 / ttl;
	checkCol = false;
	castShadow = true;
	if ((pos.y - CGround::GetApproximateHeight(pos.x, pos.z, false)) > 10) {
		useAirLos = true;
	}
	glowFalloff = 4.5f + gu->RandFloat() * 6;
	textureNum = (int)(gu->RandInt() % projectileDrawer->smoketex.size());
}



void CSmokeProjectile2::Init(CUnit* owner, const float3& offset)
{
	textureNum = (int) (gu->RandInt() % projectileDrawer->smoketex.size());

	if (offset.y - CGround::GetApproximateHeight(offset.x, offset.z, false) > 10) {
		useAirLos = true;
	}

	if (!owner) {
		alwaysVisible = true;
	}

	wantedPos += offset;

	CProjectile::Init(owner, offset);
}

void CSmokeProjectile2::Update()
{
	wantedPos += speed;
	wantedPos += wind.GetCurrentWind() * age * 0.05f;

	pos.x += (wantedPos.x - pos.x) * 0.07f;
	pos.y += (wantedPos.y - pos.y) * 0.02f;
	pos.z += (wantedPos.z - pos.z) * 0.07f;
	age += ageSpeed;
	size += sizeExpansion;
	if (size < startSize) {
		size += (startSize - size) * 0.2f;
	}
	SetRadiusAndHeight(size, 0.0f);
	if (age > 1) {
		age = 1;
		deleteMe = true;
	}
}

void CSmokeProjectile2::Draw()
{
	inArray = true;
	const float interAge = std::min(1.0f, age + ageSpeed * globalRendering->timeOffset);
	unsigned char col[4];
	unsigned char alpha;
	if (interAge < 0.05f) {
		alpha = (unsigned char) (interAge * 19 * 127);
	} else {
		alpha = (unsigned char) ((1 - interAge) * 127);
	}
	const float rglow = std::max(0.f, (1 - (interAge * glowFalloff))        * 127);
	const float gglow = std::max(0.f, (1 - (interAge * glowFalloff * 2.5f)) * 127);
	col[0] = (unsigned char) (color * alpha + rglow);
	col[1] = (unsigned char) (color * alpha + gglow);
	col[2] = (unsigned char) std::max(0.f, color * alpha - gglow * 0.5f);
	col[3] = alpha/*-alphaFalloff*globalRendering->timeOffset*/;

	const float3 interPos = pos + (wantedPos + speed * globalRendering->timeOffset - pos) * 0.1f * globalRendering->timeOffset;
	const float interSize = size + sizeExpansion * globalRendering->timeOffset;
	const float3 pos1 ((camera->right - camera->up) * interSize);
	const float3 pos2 ((camera->right + camera->up) * interSize);

	#define st projectileDrawer->smoketex[textureNum]
	va->AddVertexTC(interPos - pos2, st->xstart, st->ystart, col);
	va->AddVertexTC(interPos + pos1, st->xend,   st->ystart, col);
	va->AddVertexTC(interPos + pos2, st->xend,   st->yend,   col);
	va->AddVertexTC(interPos - pos1, st->xstart, st->yend,   col);
	#undef st
}
