#include "Precomp.h"
#include "Texture.h"
#include <stdexcept>

Texture::Texture()
{
}

Texture::~Texture()
{
	// To do: move mTexture to a delete list as this might be called by a finalizer in a different thread
}

void Texture::Set2DImage(int width, int height)
{
	mCubeTexture = false;
	mWidth = width;
	mHeight = height;
}

void Texture::SetCubeImage(int size)
{
	mCubeTexture = true;
	mWidth = size;
	mHeight = size;
}

void Texture::SetPixels(const void* data)
{
	mPixels[0].resize(mWidth * (size_t)mHeight);
	memcpy(mPixels[0].data(), data, sizeof(uint32_t) * mWidth * mHeight);
}

void Texture::SetCubePixels(CubeMapFace face, const void* data)
{
	mPixels[(int)face].resize(mWidth * (size_t)mHeight);
	memcpy(mPixels[(int)face].data(), data, sizeof(uint32_t) * mWidth * mHeight);
}

void Texture::Invalidate()
{
	if (mDepthRenderbuffer) glDeleteRenderbuffers(1, &mDepthRenderbuffer);
	if (mFramebuffer) glDeleteFramebuffers(1, &mFramebuffer);
	if (mFramebufferDepth) glDeleteFramebuffers(1, &mFramebufferDepth);
	if (mTexture) glDeleteTextures(1, &mTexture);
	mDepthRenderbuffer = 0;
	mFramebuffer = 0;
	mFramebufferDepth = 0;
	mTexture = 0;
}

GLuint Texture::GetTexture()
{
	if (mTexture == 0)
	{
		GLint oldActiveTex = GL_TEXTURE0;
		glGetIntegerv(GL_ACTIVE_TEXTURE, &oldActiveTex);
		glActiveTexture(GL_TEXTURE0);

		glGenTextures(1, &mTexture);

		if (!IsCubeTexture())
		{
			GLint oldBinding = 0;
			glGetIntegerv(GL_TEXTURE_BINDING_2D, &oldBinding);

			glBindTexture(GL_TEXTURE_2D, mTexture);
			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, mWidth, mHeight, 0, GL_BGRA, GL_UNSIGNED_BYTE, !mPixels[0].empty() ? mPixels[0].data() : nullptr);
			if (!mPixels[0].empty())
				glGenerateMipmap(GL_TEXTURE_2D);

			glBindTexture(GL_TEXTURE_2D, oldBinding);
		}
		else
		{
			GLint oldBinding = 0;
			glGetIntegerv(GL_TEXTURE_BINDING_CUBE_MAP, &oldBinding);

			glBindTexture(GL_TEXTURE_CUBE_MAP, mTexture);
			glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X, 0, GL_RGBA8, mWidth, mHeight, 0, GL_BGRA, GL_UNSIGNED_BYTE, !mPixels[0].empty() ? mPixels[0].data() : nullptr);
			glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_Y, 0, GL_RGBA8, mWidth, mHeight, 0, GL_BGRA, GL_UNSIGNED_BYTE, !mPixels[1].empty() ? mPixels[1].data() : nullptr);
			glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_Z, 0, GL_RGBA8, mWidth, mHeight, 0, GL_BGRA, GL_UNSIGNED_BYTE, !mPixels[2].empty() ? mPixels[2].data() : nullptr);
			glTexImage2D(GL_TEXTURE_CUBE_MAP_NEGATIVE_X, 0, GL_RGBA8, mWidth, mHeight, 0, GL_BGRA, GL_UNSIGNED_BYTE, !mPixels[3].empty() ? mPixels[3].data() : nullptr);
			glTexImage2D(GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, 0, GL_RGBA8, mWidth, mHeight, 0, GL_BGRA, GL_UNSIGNED_BYTE, !mPixels[4].empty() ? mPixels[4].data() : nullptr);
			glTexImage2D(GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, 0, GL_RGBA8, mWidth, mHeight, 0, GL_BGRA, GL_UNSIGNED_BYTE, !mPixels[5].empty() ? mPixels[5].data() : nullptr);
			if (!mPixels[0].empty())
				glGenerateMipmap(GL_TEXTURE_CUBE_MAP);

			glBindTexture(GL_TEXTURE_CUBE_MAP, oldBinding);
		}

		glActiveTexture(oldActiveTex);
	}
	return mTexture;
}

GLuint Texture::GetFramebuffer(bool usedepthbuffer)
{
	if (!usedepthbuffer)
	{
		if (mFramebuffer == 0)
		{
			GLuint texture = GetTexture();
			glGenFramebuffers(1, &mFramebuffer);
			glBindFramebuffer(GL_FRAMEBUFFER, mFramebuffer);
			glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
			if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
				throw std::runtime_error("glCheckFramebufferStatus did not return GL_FRAMEBUFFER_COMPLETE");
		}
		return mFramebuffer;
	}
	else
	{
		if (mFramebuffer == mFramebufferDepth)
		{
			if (mDepthRenderbuffer == 0)
			{
				glGenRenderbuffers(1, &mDepthRenderbuffer);
				glBindRenderbuffer(GL_RENDERBUFFER, mDepthRenderbuffer);
				glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, mWidth, mHeight);
				glBindRenderbuffer(GL_RENDERBUFFER, 0);
			}

			GLuint texture = GetTexture();
			glGenFramebuffers(1, &mFramebuffer);
			glBindFramebuffer(GL_FRAMEBUFFER, mFramebuffer);
			glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
			glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, mDepthRenderbuffer);
			if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
				throw std::runtime_error("glCheckFramebufferStatus did not return GL_FRAMEBUFFER_COMPLETE");
		}
		return mFramebufferDepth;
	}
}

/////////////////////////////////////////////////////////////////////////////

Texture* Texture_New()
{
	return new Texture();
}

void Texture_Delete(Texture* tex)
{
	//delete tex;
}

void Texture_Set2DImage(Texture* handle, int width, int height)
{
	handle->Set2DImage(width, height);
}

void Texture_SetCubeImage(Texture* handle, int size)
{
	handle->SetCubeImage(size);
}