#include "adapter_texture.h"
#include <SDL3/SDL_opengl.h>

#include "device/dvc_render_target.h"
#include "math/dvc_math_util.h"

AdapterTexture::AdapterTexture()
	: m_canvasTexture(0)
	, m_canvasWidth(0)
	, m_canvasHeight(0)
	, m_textureWidth(0)
	, m_textureHeight(0)
	, m_textureBuff(nullptr)
{
}

AdapterTexture::~AdapterTexture()
{
	if (m_textureBuff != nullptr)
	{
		delete[] m_textureBuff;
		m_textureBuff = nullptr;
	}
}

void AdapterTexture::init(int32_t canvasWidth, int32_t canvasHeight)
{
	// load and create a texture 
	glGenTextures(1, &m_canvasTexture);
	glBindTexture(GL_TEXTURE_2D, m_canvasTexture);

	// set texture filtering parameters
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	//create texture buff
	resize(canvasWidth, canvasHeight);
}

void AdapterTexture::resize(int32_t canvasWidth, int32_t canvasHeight)
{
	m_canvasWidth = canvasWidth;
	m_canvasHeight = canvasHeight;

	//upbound to 4
	int32_t textureWidth = canvasWidth;
	if ((textureWidth & 3) != 0) {
		textureWidth = (textureWidth & (~3)) + 4;
	}
	int32_t textureHeight = canvasHeight;
	if ((textureHeight & 3) != 0) {
		textureHeight = (textureHeight & (~3)) + 4;
	}

	//same texture size?
	if (m_textureWidth == textureWidth && m_textureHeight == textureHeight)
	{
		return;
	}
	m_textureWidth = textureWidth;
	m_textureHeight = textureHeight;

	if (m_textureBuff != nullptr)
	{
		delete[] m_textureBuff;
	}

	//alloc new texture memory buf
	m_textureBuff = new uint8_t[textureWidth * textureHeight * 3];
	memset(m_textureBuff, 0, textureWidth * textureHeight * 3);
}

void AdapterTexture::updateTexture(void)
{
	if (m_textureBuff == nullptr || m_textureWidth == 0 || m_textureHeight == 0)
	{
		//not ready?
		return;
	}

	//fill as blank texture
	const int32_t BLOCK_SIZE = 10;
	for (int32_t i = 0; i < m_canvasHeight; i++)
	{
		uint8_t* p = m_textureBuff + i * m_textureWidth * 3;
		for (int32_t j = 0; j < m_canvasWidth; j++)
		{
			int ii = i / BLOCK_SIZE;
			int jj = j / BLOCK_SIZE;
			bool i_odd = (ii & 1) != 0;
			bool j_odd = (jj & 1) != 0;

			if (i_odd != j_odd)
			{
				*p++ = (uint8_t)(1 * 255);
				*p++ = (uint8_t)(1 * 255);
				*p++ = (uint8_t)(1 * 255);
			}
			else
			{
				*p++ = (uint8_t)(1 * 220);
				*p++ = (uint8_t)(1 * 220);
				*p++ = (uint8_t)(1 * 220);
			}
		}
	}

	glBindTexture(GL_TEXTURE_2D, m_canvasTexture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, m_textureWidth, m_textureHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, m_textureBuff);
}

void AdapterTexture::updateTexture(int32_t start_x, int32_t start_y, const davinci::PixelBuffer<davinci::fVector4>& buffer)
{
	int32_t width = buffer.getWidth();
	int32_t height = buffer.getHeight();

	for (int32_t i = 0; i < height; i++)
	{
		int32_t y = start_y + i;
		if (y >= m_canvasHeight) break;

		uint8_t* ps = m_textureBuff + y * m_textureWidth * 3;
		for (int32_t j = 0; j < width; j++)
		{
			int32_t x = start_x + j;
			if (x >= m_canvasWidth) break;

			uint8_t* p = ps + 3 * x;

			const davinci::fVector4 color = buffer.getPixel(j, i);

			*p++ = (uint8_t)(255 * color.x);
			*p++ = (uint8_t)(255 * color.y);
			*p++ = (uint8_t)(255 * color.z);
		}
		
	}
	glBindTexture(GL_TEXTURE_2D, m_canvasTexture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, m_textureWidth, m_textureHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, m_textureBuff);
}

void AdapterTexture::updateTexture(int32_t start_x, int32_t start_y, const davinci::PixelBuffer<float32_t>& buffer)
{
	int32_t width = buffer.getWidth();
	int32_t height = buffer.getHeight();

	for (int32_t i = 0; i < height; i++)
	{
		int32_t y = start_y + i;
		if (y >= m_canvasHeight) break;

		uint8_t* ps = m_textureBuff + y * m_textureWidth * 3;
		for (int32_t j = 0; j < width; j++)
		{
			int32_t x = start_x + j;
			if (x >= m_canvasWidth) break;

			uint8_t* p = ps + 3 * x;

			const float32_t color = davinci::MathUtil::saturate(buffer.getPixel(j, i));

			*p++ = (uint8_t)(255 * color);
			*p++ = (uint8_t)(255 * color);
			*p++ = (uint8_t)(255 * color);
		}

	}
	glBindTexture(GL_TEXTURE_2D, m_canvasTexture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, m_textureWidth, m_textureHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, m_textureBuff);
}

void AdapterTexture::draw(void)
{
	glBindTexture(GL_TEXTURE_2D, getTextureID());
	glBegin(GL_QUADS);

	float top_pos = (float)m_textureHeight*2.0f / (float)m_canvasHeight-1.0f;
	float right_pos = (float)m_textureWidth*2.0f / (float)m_canvasWidth-1.0f;

	glTexCoord2f(0.0, 0.0); glVertex3f(-1.0f,		-1.0f,		0);
	glTexCoord2f(1.0, 0.0); glVertex3f(right_pos,	-1.0f,		0);
	glTexCoord2f(1.0, 1.0); glVertex3f(right_pos,	top_pos,	0);
	glTexCoord2f(0.0, 1.0); glVertex3f(-1.0f,		top_pos,	0);
	glEnd();
}