#include "dvr_canvas.h"

#include <array>

#define SDL_MAIN_USE_CALLBACKS 1  /* use the callbacks instead of main() */
#include <SDL3/SDL.h>

void Canvas::reset(int32_t width, int32_t height)
{
	m_width = width;
	m_height = height;
	m_pixels.resize(m_width * m_height);

	for (int32_t i = 0; i < m_width * m_height; i++)
	{
		m_pixels[i].fragementID = -1;
		m_pixels[i].mask = 0;
		m_pixels[i].color = davinci::fVector3::BLACK;
	}

	m_fragementArray.clear();
}

void Canvas::_insertTriangle(const Triangle& triangle)
{
	for (size_t i = 0; i < triangle.m_pixels.size(); i++)
	{
		const Triangle::Pixel trianglePixel = triangle.m_pixels[i];
		Pixel& pixel = m_pixels[trianglePixel.y * m_width + trianglePixel.x];

		Fragement newFragement;
		newFragement.id = (int32_t)m_fragementArray.size();
		newFragement.color = triangle.m_pixelColor;
		newFragement.mask = trianglePixel.mask;
		newFragement.next = pixel.fragementID;

		pixel.fragementID = newFragement.id;
		m_fragementArray.push_back(newFragement);
	}
}

void Canvas::_update_without_AA()
{
	for (size_t i = 0; i < m_pixels.size(); i++)
	{
		Pixel& pixel = m_pixels[i];
		if (pixel.fragementID < 0) continue;

		const Fragement& fragement = m_fragementArray[pixel.fragementID];
		pixel.mask = fragement.mask;
		pixel.color = fragement.color;
		pixel.alpha = 1.f;
	}
}

void Canvas::update(davinci::AntiAliasingTech aaTech, const TriangleArray& triangleArray, const Triangle* pActionTriangle)
{
	reset(m_width, m_height);

	for (size_t i = 0; i < triangleArray.size(); i++)
	{
		const Triangle& triangle = triangleArray[i];
		_insertTriangle(triangle);
	}

	if (pActionTriangle != nullptr)
	{
		_insertTriangle(*pActionTriangle);
	}

	if (aaTech == davinci::AntiAliasingTech::AA_None)
	{
		_update_without_AA();
	}
	else if (aaTech == davinci::AntiAliasingTech::AA_MSAA_2X2)
	{
		_update_with_AA<4>();
	}
	else if ( aaTech == davinci::AntiAliasingTech::AA_MSAA_4X4)
	{
		_update_with_AA<16>();
	}
}