//video.c
// 08/13/03 Josh Holtrop
// Modified: 11/12/03


//Initialized the video mode information block video_mode and allocated double-buffer memory for graphics display
void video_init(ModeInfoBlock *mib)
{
	video_mode = *mib;

	//Get a buffer region in memory for double-buffering video memory in 32bpp
	vid_Buffer = mm_palloc((4*video_mode.XResolution*video_mode.YResolution)/4096+1, PID_KERNEL);
	if ((dword)vid_Buffer == 0)
	{
		printf("ERROR - COULD NOT ALLOCATE MEMORY FOR VIDEO DOUBLE-BUFFER!!\n");
		halt();
	}
	dword tot = ((video_mode.XResolution) * (video_mode.YResolution));
	int a;
	for (a = 0; a < tot; a++)
	{
		if (a < (tot / 4))
			vid_Buffer[a] = 0x00FF0000;
		else if (a < (tot / 2))
			vid_Buffer[a] = 0x0000FF00;
		else if (a < ((tot * 3) / 4))
			vid_Buffer[a] = 0x000000FF;
		else
			vid_Buffer[a] = 0x00FFFFFF;
	}

	int VXR = video_mode.XResolution;
	int VYR = video_mode.YResolution;

	video_rectf(VXR*3/11, 0, VXR*4/11, VYR-1, 0x00000088);      		//test rectangles, draws "HOS"
	video_rectf(VXR*7/11, 0, VXR*8/11, VYR-1, 0x00000088);
	video_rectf(VXR/11, 0, VXR*2/11, VYR*2/5, 0x00000088);
	video_rectf(VXR/11, VYR*3/5, VXR*2/11, VYR-1, 0x00000088);
	video_rectf(VXR*5/11, VYR/5, VXR*6/11, VYR*4/5, 0x00000088);
	video_rectf(VXR*9/11, VYR/5, VXR-1, VYR*2/5, 0x00000088);
	video_rectf(VXR*8/11, VYR*3/5, VXR*10/11, VYR*4/5, 0x00000088);

	
	int b;
	for (a = 0; a < 256; a++)
	{
		for (b = 0; b < 256; b++)
		{
			video_pset(a+5, b+30, (a<<16)|(b<<8));
			video_pset(a+270, b+30, (a<<8)|(b));
			video_pset(a+535, b+30, (a<<16)|(b));

			video_pset(a+5, b+290, (a<<16)|(b<<8)|0x000000ff);
			video_pset(a+270, b+290, (a<<8)|(b)|0x00ff0000);
			video_pset(a+535, b+290, (a<<16)|(b)|0x0000ff00);
		}
	}
	
	int fx;
	int fy = 25;
	int fc;
	int fr;
	for (fr = 0; fr < 16; fr++)
	{
		fx = 15;
		for (fc = 0; fc < 16; fc++)
		{
			video_renderChar(fx, fy, fr*16+fc, 0xFFFFFF);
			fx += 8;
		}
		fy += 10;
	}

	video_copyBuffer();
}

//Renders a character using stdfont[] as a bitmask
void video_renderChar(int x, int y, int character, dword color)
{
	int charpos = (character & 0xFF) * 8;
	int row;
	int col;
	for (row = 0; row < 8; row++)
	{
		for (col = 0; col < 5; col++)
		{
			if ((stdfont[charpos+row] >> (col+3)) & 0x01)
				video_pset(x+(5-col), y+row, color);
		}
	}
}

//Draws a horizontal line
void video_horiz(int y, int x1, int x2, dword color)
{
	if (x1 > x2)
	{
		int tmp = x2;
		x2 = x1;
		x1 = tmp;		//x2 >= x1 now
	}
	if (x2 < 0)
		return;
	if (x1 > video_mode.XResolution)
		return;
	if (x1 < 0)
		x1 = 0;
	if (x2 > video_mode.XResolution)
		x2 = video_mode.XResolution;
	int pixel = y*video_mode.XResolution+x1;
	for (; x1 <= x2; x1++)
	{
		vid_Buffer[pixel++] = color;
	}
}

//Draws a vertical line
void video_vert(int x, int y1, int y2, dword color)
{
	if (y1 > y2)
	{
		int tmp = y2;
		y2 = y1;
		y1 = tmp;		//y2 >= y1 now
	}
	if (y2 < 0)
		return;
	if (y1 > video_mode.YResolution)
		return;
	if (y1 < 0)
		y1 = 0;
	if (y2 > video_mode.YResolution)
		y2 = video_mode.YResolution;
	int pixel = y1*video_mode.XResolution+x;
	for (; y1 <= y2; y1++)
	{
		vid_Buffer[pixel] = color;
		pixel+=video_mode.XResolution;
	}
}

//Draws a rectangle
void video_rect(int x1, int y1, int x2, int y2, dword color)
{
	video_horiz(y1, x1, x2, color);
	video_horiz(y2, x1, x2, color);
	video_vert(x1, y1, y2, color);
	video_vert(x2, y1, y2, color);
}

//Draws a filled rectangle
void video_rectf(int x1, int y1, int x2, int y2, dword color)
{
	if (y2 < y1)
	{
		int tmp = y2;
		y2 = y1;
		y1 = tmp;
	}
	for (; y1 <= y2; y1++)
		video_horiz(y1, x1, x2, color);
}

//Draws a single pixel
inline void video_pset(int x, int y, dword color)
{
	if ((x < 0) || (x > video_mode.XResolution) || (y < 0) || (y > video_mode.YResolution))
		return;
	vid_Buffer[y*video_mode.XResolution+x] = color;
}

//Copies double-buffer to VESA Linear Frame Buffer
void video_copyBuffer()
{
 	switch (video_mode.BitsPerPixel)
	{
		case 32:
			video_copyBuffer32((dword)vid_Buffer, video_mode.PhysBasePtr, video_mode.XResolution*video_mode.YResolution);
			break;
		case 24:
			video_copyBuffer24((dword)vid_Buffer, video_mode.PhysBasePtr, video_mode.XResolution*video_mode.YResolution);
			break;
		case 16:
			video_copyBuffer16((dword)vid_Buffer, video_mode.PhysBasePtr, video_mode.XResolution*video_mode.YResolution);
			break;
	}
 	/*int pixel;
 	dword color;
 	for (pixel = 0; pixel < video_mode.XResolution*video_mode.YResolution; pixel++)
 	{
		switch(video_mode.BitsPerPixel)
		{
		case 16:
			color = vid_Buffer[pixel];
			((word *)video_mode.PhysBasePtr)[pixel] = ((color&0xFF)>>3) | ((((color>>8)&0xFF)>>2)<<5) | ((((color>>16)&0xFF)>>3)<<11);
			//vid_ptr16[pixel] = ((color&0xFF)>>3) | ((((color>>8)&0xFF)>>3)<<5) | ((((color>>16)&0xFF)>>3)<<10); //15 bit mode?
			break;
		case 24:
			color = vid_Buffer[pixel];
			((byte *)video_mode.PhysBasePtr)[pixel*3] = color & 0xFF;
			((byte *)video_mode.PhysBasePtr)[pixel*3+1] = (color>>8) & 0xFF;
			((byte *)video_mode.PhysBasePtr)[pixel*3+2] = (color>>16) & 0xFF;
			break;
		case 32:
			color = vid_Buffer[pixel];
			((dword *)video_mode.PhysBasePtr)[pixel] = color;
		}
	 }    */
}