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


#include "DirtProjectile.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"

CR_BIND_DERIVED(CDirtProjectile, CProjectile, );

CR_REG_METADATA(CDirtProjectile,
(
	CR_MEMBER_BEGINFLAG(CM_Config),
		CR_MEMBER(alpha),
		CR_MEMBER(alphaFalloff),
		CR_MEMBER(size),
		CR_MEMBER(sizeExpansion),
		CR_MEMBER(slowdown),
		CR_MEMBER(color),
		CR_MEMBER(texture),
	CR_MEMBER_ENDFLAG(CM_Config),
	CR_RESERVED(8)
));

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

CDirtProjectile::CDirtProjectile(
	CUnit* owner,
	const float3& pos,
	const float3& speed,
	const float ttl,
	const float size,
	const float expansion,
	float slowdown,
	const float3& color
):
	CProjectile(pos, speed, owner, false, false, false),

	alpha(255),
	size(size),
	sizeExpansion(expansion),
	slowdown(slowdown),
	color(color)
{
	checkCol = false;
	alphaFalloff = 255 / ttl;
	texture = projectileDrawer->randdotstex;
}

CDirtProjectile::CDirtProjectile() :
	CProjectile(),
	alpha(255.0f),
	alphaFalloff(10.0f),
	size(10.0f),
	sizeExpansion(0.0f),
	slowdown(1.0f)
{
	checkCol = false;
	texture = projectileDrawer->randdotstex;
}

CDirtProjectile::~CDirtProjectile()
{}

void CDirtProjectile::Update()
{
	SetVelocityAndSpeed((speed * slowdown) + (UpVector * mygravity));
	SetPosition(pos + speed);

	alpha = std::max(alpha - alphaFalloff, 0.0f);
	size += sizeExpansion;

	if (ground->GetApproximateHeight(pos.x, pos.z, false) - 40.0f > pos.y) {
		deleteMe = true;
	}
	if (alpha <= 0.0f) {
		deleteMe = true;
	}
}

void CDirtProjectile::Draw()
{
	float partAbove = (pos.y / (size * camera->up.y));
	if (partAbove < -1) {
		return;
	} else if (partAbove > 1) {
		partAbove = 1;
	}
	inArray = true;
	unsigned char col[4];
	col[0] = (unsigned char) (color.x * alpha);
	col[1] = (unsigned char) (color.y * alpha);
	col[2] = (unsigned char) (color.z * alpha);
	col[3] = (unsigned char) (alpha)/*- (globalRendering->timeOffset * alphaFalloff)*/;

	const float interSize = size + globalRendering->timeOffset * sizeExpansion;
	const float texx = texture->xstart + (texture->xend - texture->xstart) * ((1.0f - partAbove) * 0.5f);

	va->AddVertexTC(drawPos - camera->right * interSize - camera->up * interSize * partAbove, texx,          texture->ystart, col);
	va->AddVertexTC(drawPos + camera->right * interSize - camera->up * interSize * partAbove, texx,          texture->yend,   col);
	va->AddVertexTC(drawPos + camera->right * interSize + camera->up * interSize,             texture->xend, texture->yend,   col);
	va->AddVertexTC(drawPos - camera->right * interSize + camera->up * interSize,             texture->xend, texture->ystart, col);
}
