// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id: c01565ae511c254df8db3526602645257508024c $
//
// Copyright (C) 1993-1996 by id Software, Inc.
// Copyright (C) 2006-2026 by The Odamex Team.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//		Functions to draw patches (by post) directly to screen->
//		Functions to blit a block to the screen->
//
//-----------------------------------------------------------------------------


#include "odamex.h"

#include <assert.h>
#include <cmath>

#include "i_system.h"
#include "i_time.h"
#include "i_video.h"
#include "r_local.h"
#include "r_draw.h"
#include "r_state.h"

#include "d_main.h"

#include "c_console.h"

#include "m_argv.h"
#include "m_bbox.h"

#include "v_video.h"
#include "v_text.h"

#include "w_wad.h"
#include "z_zone.h"

#include "c_dispatch.h"
#include "cmdlib.h"

#include "f_wipe.h"

IMPLEMENT_CLASS (DCanvas, DObject)

argb_t Col2RGB8[65][256];
palindex_t RGB32k[32][32][32];

// [RH] The framebuffer is no longer a mere byte array.
// There's also only one, not four.
DCanvas *screen;

static DBoundingBox dirtybox;

static bool V_DoSetResolution();
static void BuildTransTable(const argb_t* palette_colors);

// flag to indicate that V_AdjustVideoMode should try to change the video mode
static bool setmodeneeded = false;


//
//	V_ForceVideoModeAdjustment
//
// Tells the video subsystem to change the video mode and recalculate any
// lookup tables dependent on the video mode prior to drawing the next frame.
//
void V_ForceVideoModeAdjustment()
{
	setmodeneeded = true;
}


//
// V_AdjustVideoMode
//
// Checks if the video mode needs to be changed and calls several video mode
// dependent initialization routines if it does. This should be called at the
// start of drawing a video frame.
//
void V_AdjustVideoMode()
{
	if (setmodeneeded)
	{
		setmodeneeded = false;

		// [SL] surface buffer address will be changing
		// so just end the screen-wipe
		Wipe_Stop();

		// Change screen mode.
		if (!V_DoSetResolution())
			I_FatalError("Could not change screen mode");

		// Refresh the console.
		C_NewModeAdjust();

		// Recalculate various view parameters.
		R_ForceViewWindowResize();
	}
}


EXTERN_CVAR(vid_defwidth)
EXTERN_CVAR(vid_defheight)
EXTERN_CVAR(vid_32bpp)
EXTERN_CVAR(vid_fullscreen)
EXTERN_CVAR(vid_filter)
EXTERN_CVAR(vid_widescreen)
EXTERN_CVAR(sv_allowwidescreen)
EXTERN_CVAR(vid_vsync)
EXTERN_CVAR(vid_pillarbox)
EXTERN_CVAR(vid_displayfps)
EXTERN_CVAR(vid_640x400)
EXTERN_CVAR(vid_320x200)

static int vid_pillarbox_old = -1;
static int vid_widescreen_old = -1;


static IVideoMode V_GetRequestedVideoMode()
{
	const int surface_bpp = vid_32bpp ? 32 : 8;
	const EWindowMode window_mode = (EWindowMode)vid_fullscreen.asInt();
	const bool vsync = (vid_vsync != 0.0f);
	const std::string& stretch_mode(vid_filter);

	return IVideoMode(vid_defwidth.asInt(), vid_defheight.asInt(), surface_bpp, window_mode, vsync, stretch_mode);
}


bool V_CheckModeAdjustment()
{
	const IWindow* window = I_GetWindow();
	if (!window)
		return false;

	if (V_GetRequestedVideoMode() != window->getVideoMode())
		return true;

	const bool allow_widescreen = sv_allowwidescreen != 0.0f;
	if (vid_widescreen.asInt() > 0 && allow_widescreen != I_IsWideResolution())
		return true;

	if (vid_widescreen.asInt() != vid_widescreen_old)
	{
		vid_widescreen_old = vid_widescreen.asInt();
		return true;
	}

	if (vid_pillarbox_old != vid_pillarbox)
	{
		vid_pillarbox_old = vid_pillarbox;
		return true;
	}

	return false;
}


CVAR_FUNC_IMPL(vid_defwidth)
{
	if (var < 320 || var > MAXWIDTH)
		var.RestoreDefault();

	if (gamestate != GS_STARTUP && V_CheckModeAdjustment())
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_defheight)
{
	if (var < 200 || var > MAXHEIGHT)
		var.RestoreDefault();

	if (gamestate != GS_STARTUP && V_CheckModeAdjustment())
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_fullscreen)
{
	if (gamestate != GS_STARTUP && V_CheckModeAdjustment())
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_filter)
{
	if (gamestate != GS_STARTUP && V_CheckModeAdjustment())
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_32bpp)
{
	if (gamestate != GS_STARTUP && V_CheckModeAdjustment())
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_vsync)
{
	if (gamestate != GS_STARTUP && V_CheckModeAdjustment())
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_overscan)
{
	if (gamestate != GS_STARTUP)
		V_ForceVideoModeAdjustment();
}

CVAR_FUNC_IMPL(vid_320x200)
{
	// vid_320x200 and vid_640x400 cannot both be enabled
	if (var == 1)
		vid_640x400.Set(0.0);
	if (gamestate != GS_STARTUP)
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_640x400)
{
	// vid_320x200 and vid_640x400 cannot both be enabled
	if (var == 1)
		vid_320x200.Set(0.0);
	if (gamestate != GS_STARTUP)
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL (vid_widescreen)
{
	if (var < 0 || var > 5)
		var.RestoreDefault();

	if (gamestate != GS_STARTUP && V_CheckModeAdjustment())
		V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_pillarbox)
{
	if (gamestate != GS_STARTUP && V_CheckModeAdjustment())
		V_ForceVideoModeAdjustment();
}

//
// Only checks to see if the widescreen mode is proper compared to sv_allowwidescreen.
//
// Doing a full check on Windows results in strange flashing behavior in fullscreen
// because there's an 32-bit surface being rendered to as 8-bit.
//
static bool CheckWideModeAdjustment()
{
	const bool using_widescreen = I_IsWideResolution();
	const bool allow_widescreen = sv_allowwidescreen != 0.0f;
	if (vid_widescreen.asInt() > 0 && allow_widescreen != using_widescreen)
		return true;

	if ((vid_widescreen.asInt() > 0) != using_widescreen)
		return true;

	return false;
}

CVAR_FUNC_IMPL (sv_allowwidescreen)
{
	if (!I_VideoInitialized() || gamestate == GS_STARTUP)
		return;

	if (!CheckWideModeAdjustment())
		return;

	V_ForceVideoModeAdjustment();
}


CVAR_FUNC_IMPL(vid_maxfps)
{
	if (var == 0)
	{
		capfps = false;
		maxfps = 99999.0f;
	}
	else
	{
		if (var < 35.0f)
			var.Set(35.0f);
		else
		{
			capfps = true;
			maxfps = var;
		}
	}
}


//
// vid_listmodes
//
// Prints a list of all supported video modes, highlighting the current
// video mode. Requires I_VideoInitialized() to be true.
//
BEGIN_COMMAND(vid_listmodes)
{
	for (const auto& mode : *I_GetVideoCapabilities()->getSupportedVideoModes())
	{
		if (mode == I_GetWindow()->getVideoMode())
			PrintFmt_Bold("{}\n", I_GetVideoModeString(mode));
		else
			PrintFmt(PRINT_HIGH, "{}\n", I_GetVideoModeString(mode));
	}
}
END_COMMAND(vid_listmodes)


//
// vid_currentmode
//
// Prints the current video mode. Requires I_VideoInitialized() to be true.
//
BEGIN_COMMAND(vid_currentmode)
{
	std::string pixel_string;

	const PixelFormat* format = I_GetWindow()->getPrimarySurface()->getPixelFormat();
	if (format->getBitsPerPixel() == 8)
	{
		pixel_string = "palettized";
	}
	else
	{
		char temp_str[9] = { 0 };
		argb_t* d1 = (argb_t*)temp_str;
		argb_t* d2 = (argb_t*)temp_str + 1;

		d1->seta('A'); d1->setr('R'); d1->setg('G'); d1->setb('B');
		d2->seta('0' + format->getABits()); d2->setr('0' + format->getRBits());
		d2->setg('0' + format->getGBits()); d2->setb('0' + format->getBBits());

		pixel_string = std::string(temp_str);
	}

	const IVideoMode& mode = I_GetWindow()->getVideoMode();
	PrintFmt(PRINT_HIGH, "{} {} surface\n",
			I_GetVideoModeString(mode), pixel_string);
}
END_COMMAND(vid_currentmode)


BEGIN_COMMAND(checkres)
{
	PrintFmt(PRINT_HIGH, "{}x{}\n", I_GetVideoWidth(), I_GetVideoHeight());
}
END_COMMAND(checkres)


//
// vid_setmode
//
// Sets the video mode resolution.
// The actual change of resolution will take place at the start of the next frame.
//
BEGIN_COMMAND(vid_setmode)
{
	int width = 0, height = 0;

	// No arguments
	if (argc == 1)
	{
		PrintFmt(PRINT_HIGH, "Usage: vid_setmode <width> <height>\n");
		return;
	}

	// Width
	if (argc > 1)
		width = atoi(argv[1]);

	// Height (optional)
	if (argc > 2)
		height = atoi(argv[2]);
	if (height == 0)
		height = vid_defheight;

	if (width < 320 || height < 200)
	{
		PrintFmt(PRINT_WARNING, "{}x{} is too small.  Minimum resolution is 320x200.\n", width, height);
		return;
	}

	if (width > MAXWIDTH || height > MAXHEIGHT)
	{
		PrintFmt(PRINT_WARNING, "{}x{} is too large.  Maximum resolution is {}x{}.\n", width, height, MAXWIDTH, MAXHEIGHT);
		return;
	}

	vid_defwidth.Set(width);
	vid_defheight.Set(height);
}
END_COMMAND (vid_setmode)

//
// V_UseWidescreen
//
//
bool V_UseWidescreen()
{
	const int width = I_GetVideoWidth(), height = I_GetVideoHeight();

	if (width == 0 || height == 0)
		return false;

	if (I_IsProtectedResolution(width, height))
		return false;

	if (vid_320x200 || vid_640x400)
		return true;

	return (vid_widescreen.asInt() > 0 && (serverside || sv_allowwidescreen));
}


//
// V_DoSetResolution
//
// Changes the video resolution to the given dimensions. This should only
// be called at the begining of drawing a frame (or during startup)!
//
static bool V_DoSetResolution()
{
	const IVideoMode requested_mode = V_GetRequestedVideoMode();

	I_SetVideoMode(requested_mode);
	if (!I_VideoInitialized())
		return false;

	V_Init();

	return true;
}



//
// V_Close
//
void STACK_ARGS V_Close()
{
	R_ShutdownColormaps();
}


//
// V_Init
//
void V_Init()
{
	if (!I_VideoInitialized())
	{
		int video_width = M_GetParmValue("-width");
		int video_height = M_GetParmValue("-height");
		int video_bpp = M_GetParmValue("-bits");

		// ensure the width & height cvars are sane
		if (vid_defwidth.asInt() <= 0 || vid_defheight.asInt() <= 0)
		{
			vid_defwidth.RestoreDefault();
			vid_defheight.RestoreDefault();
		}

		if (video_width == 0 && video_height == 0)
		{
			video_width = vid_defwidth.asInt();
			video_height = vid_defheight.asInt();
		}
		else if (video_width == 0)
		{
			video_width = video_height * 4 / 3;
		}
		else if (video_height == 0)
		{
			video_height = video_width * 3 / 4;
		}

		vid_defwidth.Set(video_width);
		vid_defheight.Set(video_height);

		if (video_bpp == 0 || (video_bpp != 8 && video_bpp != 32))
			video_bpp = vid_32bpp ? 32 : 8;
		vid_32bpp.Set(video_bpp == 32);

		V_DoSetResolution();

		PrintFmt(PRINT_HIGH, "V_Init: using {} video driver.\n", I_GetVideoDriverName());
	}

	if (!I_VideoInitialized())
		I_FatalError("Failed to initialize display");

	V_InitPalette("PLAYPAL");

	if (realcolormaps.colormap)
		Z_Free(realcolormaps.colormap);
	if (realcolormaps.shademap)
		Z_Free(realcolormaps.shademap);

	R_InitColormaps();

	const int surface_width = I_GetSurfaceWidth(), surface_height = I_GetSurfaceHeight();

	// This uses the smaller of the two results. It's still not ideal but at least
	// this allows hud_scaletext to have some purpose...
	CleanXfac = CleanYfac = std::max(1, std::min(surface_width / 320, surface_height / 200));

	R_InitColumnDrawers();

	I_SetWindowCaption(D_GetTitleString());
	I_SetWindowIcon();

	// notify the console of changes in the screen resolution
	C_NewModeAdjust();

	BuildTransTable(V_GetDefaultPalette()->basecolors);

	vid_pillarbox_old = vid_pillarbox;
	vid_widescreen_old = vid_widescreen.asInt();
}


//
// V_MarkRect
//
void V_MarkRect(int x, int y, int width, int height)
{
	dirtybox.AddToBox(x, y);
	dirtybox.AddToBox(x + width - 1, y + height - 1);
}

constexpr int GRAPH_WIDTH = 140;
constexpr int GRAPH_HEIGHT = 80;
constexpr double GRAPH_BASELINE = 1000 / 60.0;
constexpr double GRAPH_CAPPED_BASELINE = 1000 / 35.0;

struct frametimeGraph_t
{
	double data[256];
	size_t tail; // Next insert location.
	double minimum;
	double maximum;

	frametimeGraph_t() : tail(0), minimum(::GRAPH_BASELINE), maximum(::GRAPH_BASELINE)
	{
		ArrayInit(data, ::GRAPH_BASELINE);
	}

	void clear()
	{
		ArrayInit(data, ::GRAPH_BASELINE);
		tail = 0;
		minimum = ::GRAPH_BASELINE;
		maximum = ::GRAPH_BASELINE;
	}

	void refit()
	{
		double newmin = data[0];
		double newmax = data[0];

		for (size_t i = 0; i < ARRAY_LENGTH(data); i++)
		{
			if (data[i] < newmin)
				newmin = data[i];
			if (data[i] > newmax)
				newmax = data[i];
		}

		// Round to nearest power of two.
		if (newmin <= 0.0)
		{
			minimum = 0.0;
		}
		else
		{
			double low = ::GRAPH_BASELINE;
			while (low > newmin)
				low /= 2;
			minimum = low;
		}

		if (newmax >= 1000.0)
		{
			newmax = 1000.0;
		}
		else
		{
			double hi = ::GRAPH_BASELINE;
			while (hi < newmax)
				hi *= 2;
			maximum = hi;
		}
	}

	void push(const double val)
	{
		if (val < minimum)
			minimum = val;
		if (val > maximum)
			maximum = val;

		data[tail] = val;
		tail = (tail + 1) & 0xFF;
	}

	double getTail(const size_t i) const
	{
		const size_t idx = (tail - 1 - i) & 0xFF;
		return data[idx];
	}

	double normalize(const double n) const
	{
		return (n - minimum) / (maximum - minimum);
	}
} g_GraphData;

//
// V_DrawFPSWidget
//
void V_DrawFPSWidget()
{
	static const dtime_t ONE_SECOND = I_ConvertTimeFromMs(1000);

	static dtime_t last_time = I_GetTime();
	static dtime_t time_accum = 0;
	static unsigned int frame_count = 0;

	const dtime_t current_time = I_GetTime();
	const dtime_t delta_time = current_time - last_time;
	last_time = current_time;
	frame_count++;

	if (delta_time > ONE_SECOND || delta_time <= 0)
	{
		// Just turned on or re-enabled the graph.
		::g_GraphData.clear();
	}
	else if (vid_displayfps.asInt() == FPS_FULL)
	{
		static std::string buffer;
		static double last_fps = 0.0;
		const double delta_time_ms = 1000.0 * double(delta_time) / ONE_SECOND;

		::g_GraphData.push(delta_time_ms);

		const rectInt_t graphBox =
		    M_RectFromDimensions(v2int_t(8, I_GetSurfaceHeight() / 2 + 16),
		                         v2int_t(::GRAPH_WIDTH, ::GRAPH_HEIGHT));

		// Data
		for (int count = 1; count < ::GRAPH_WIDTH - 2; count++)
		{
			const double start = ::g_GraphData.getTail(count - 1);
			const double end = ::g_GraphData.getTail(count);

			const int startoff = ::g_GraphData.normalize(start) * (::GRAPH_HEIGHT - 2);
			const int endoff = ::g_GraphData.normalize(end) * (::GRAPH_HEIGHT - 2);

			const v2int_t startvec(graphBox.max.x - count, graphBox.max.y - startoff);
			const v2int_t endvec(graphBox.max.x - count - 1, graphBox.max.y - endoff);

			screen->Line(startvec, endvec, argb_t(255, 255, 255));
		}

		// 35fps baseline
		const int baseY35 =
		    ::g_GraphData.normalize(::GRAPH_CAPPED_BASELINE) * (::GRAPH_HEIGHT - 2);
		const int offY35 = graphBox.max.y - baseY35;
		if (offY35 > graphBox.min.y && offY35 < graphBox.max.y)
		{
			screen->Line(v2int_t(graphBox.min.x, offY35), v2int_t(graphBox.max.x, offY35),
			             argb_t(0x00, 0x00, 0xff));
		}

		// 60fps Baseline
		const int baseY60 =
		    ::g_GraphData.normalize(::GRAPH_BASELINE) * (::GRAPH_HEIGHT - 2);
		const int offY60 = graphBox.max.y - baseY60;
		if (offY60 > graphBox.min.y && offY60 < graphBox.max.y)
		{
			screen->Line(v2int_t(graphBox.min.x, offY60), v2int_t(graphBox.max.x, offY60),
			             argb_t(0x00, 0xff, 0x00));
		}

		// Box
		screen->Box(graphBox, argb_t(0xcb, 0xcb, 0xcb));

		// Box Shadow
		screen->Line(v2int_t(graphBox.min.x + 1, graphBox.max.y + 1),
		             v2int_t(graphBox.max.x + 1, graphBox.max.y + 1),
		             argb_t(0x13, 0x13, 0x13));
		screen->Line(v2int_t(graphBox.max.x + 1, graphBox.min.y + 1),
		             v2int_t(graphBox.max.x + 1, graphBox.max.y + 1),
		             argb_t(0x13, 0x13, 0x13));

		// Min
		buffer = fmt::sprintf("%4.1f", ::g_GraphData.minimum);
		screen->PrintStr(graphBox.max.x, graphBox.max.y - 3, buffer.c_str());

		// Max
		buffer = fmt::sprintf("%4.1f", ::g_GraphData.maximum);
		screen->PrintStr(graphBox.max.x, graphBox.min.y - 3, buffer.c_str());

		// Actual
		buffer = fmt::sprintf("%4.1f", delta_time_ms);
		screen->PrintStr(graphBox.max.x, graphBox.min.y + (::GRAPH_HEIGHT / 2) - 3,
		                 buffer.c_str());

		// Name
		screen->PrintStr(graphBox.min.x, graphBox.min.y - 8, "Frametime (ms)");

		time_accum += delta_time;

		// calculate last_fps every 1000ms
		if (time_accum > ONE_SECOND)
		{
			last_fps = double(ONE_SECOND * frame_count) / time_accum;
			time_accum = 0;
			frame_count = 0;

			// Refit graph on next tic.
			::g_GraphData.refit();
		}

		// FPS counter
		buffer = fmt::sprintf("FPS %5.1f", last_fps);
		screen->PrintStr(graphBox.min.x, graphBox.max.y + 1, buffer.c_str());
	}
	else if (vid_displayfps.asInt() == FPS_COUNTER)
	{
		static double last_fps = 0.0;
		const v2int_t topleft(8, I_GetSurfaceHeight() / 2 + 16);
		const v2int_t botleft(topleft.x, topleft.y + ::GRAPH_HEIGHT);

		time_accum += delta_time;

		// calculate last_fps every 1000ms
		if (time_accum > ONE_SECOND)
		{
			last_fps = double(ONE_SECOND * frame_count) / time_accum;
			time_accum = 0;
			frame_count = 0;
		}

		// FPS counter
		std::string buffer;
		buffer = fmt::sprintf("FPS %5.1f", last_fps);
		screen->PrintStr(botleft.x, botleft.y + 1, buffer.c_str());
	}
}



//
// V_DrawTickerDot
//
// Templated helper function for V_DrawFPSTicker. It draws a single dot for
// the vanilla Doom FPS ticker, scaled to make the dot roughly the same size
// as it would be in 320x200 video modes.
//
template <typename PIXEL_T>
static void V_DrawTickerDot(IWindowSurface* surface, int n, PIXEL_T color)
{
	const int dot_width = CleanXfac, dot_height = CleanYfac;
	const int pitch_in_pixels = surface->getPitchInPixels();

	PIXEL_T* dest = (PIXEL_T*)surface->getBuffer() +
			(surface->getHeight() - 1 - dot_height) * pitch_in_pixels +
			2 * n * dot_width;

	for (int y = 0; y < dot_height; y++)
	{
		for (int x = 0; x < dot_width; x++)
			dest[x] = color;
		dest += pitch_in_pixels;
	}
}


//
// V_DrawFPSTicker
//
void V_DrawFPSTicker()
{
	const int current_tic = int(I_GetTime() * TICRATE / I_ConvertTimeFromMs(1000));
	static int last_tic = current_tic;

	const int tics = clamp(current_tic - last_tic, 0, 20);
	last_tic = current_tic;

	if (I_GetPrimarySurface()->getBitsPerPixel() == 8)
	{
		static constexpr palindex_t oncolor = 255;
		static constexpr palindex_t offcolor = 0;

		int n = 0;
		for (n = 0; n < tics; n++)
			V_DrawTickerDot<palindex_t>(I_GetPrimarySurface(), n, oncolor);
		for ( ; n < 20; n++)
			V_DrawTickerDot<palindex_t>(I_GetPrimarySurface(), n, offcolor);
	}
	else
	{
		const argb_t oncolor(255, 255, 255);
		const argb_t offcolor(0, 0, 0);

		int n = 0;
		for (n = 0; n < tics; n++)
			V_DrawTickerDot<argb_t>(I_GetPrimarySurface(), n, oncolor);
		for ( ; n < 20; n++)
			V_DrawTickerDot<argb_t>(I_GetPrimarySurface(), n, offcolor);
	}
}


//
// V_FindTransformedFlatPixel
//
// Determines the flat pixel to use
// when given an x/y coordinate.
// Doesn't take scaling into account. (Good todo)
//
// A flat is a 4096 byte chunk of data
// Representing a 64x64 square
//
// Each pixel is 1 byte.
//
// So we square root the lump size to get dimensions
// and put it in "flatlength"
//
// There's no posts or columns in flats; the entire
// thing is one big chunk of data assumed to be 64x64
//
// Even if the width is dynamic, a flat pixel
// will always be 1 byte, and a flat length
// will always sqrt to its height and width
// (the same number)

const byte* V_FindTransformedFlatPixel(int x, int y, unsigned int width, const byte* src)
{
	float pixelcountx = x / static_cast<float>(width);
	float pixelcounty = y / static_cast<float>(width);

	float wholex, wholey = 0;

	float flatxfrac = modff(pixelcountx, &wholex);
	float flatyfrac = modff(pixelcounty, &wholey);

	int flatx = 0;
	int flaty = 0;

	if (flatxfrac > 0)
	{
		flatx = width * flatxfrac;
	}
	else
	{
		flatx = 0;
	}

	if (flatyfrac > 0)
	{
		flaty = width * flatyfrac;
	}
	else
	{
		flaty = 0;
	}

	// Now turn these coordinates into a pixel pointer
	// Remember that flats are long unbroken buckets of data
	// So we need to transform flat x/y into a
	// lump length sized pointer array coordinate
	return src + (flatx + (flaty * width));
}

//
// DCanvas::getCleanX
//
// Returns the real screen x coordinate given the virtual 320x200 x coordinate.
//
int DCanvas::getCleanX(int x) const
{
	return (x - 160) * CleanXfac + mSurface->getWidth() / 2;
}


//
// DCanvas::getCleanY
//
// Returns the real screen y coordinate given the virtual 320x200 y coordinate.
//
int DCanvas::getCleanY(int y) const
{
	return (y - 100) * CleanYfac + mSurface->getHeight() / 2;
}


// [RH] Fill an area with an dynamic dimensions flat
// right and bottom are one pixel *past* the boundaries they describe.
//
// Rewritten to handle high resolution flats
void DCanvas::FlatFill(int left, int top, int right, int bottom, unsigned int flatlength, const byte* src) const
{
	const int surface_advance = mSurface->getPitchInPixels() - right + left;

	int width = std::sqrt(flatlength);

	if (mSurface->getBitsPerPixel() == 8)
	{
		palindex_t* dest = (palindex_t*)mSurface->getBuffer() + top * mSurface->getPitchInPixels() + left;

		for (int y = top; y < bottom; y++)
		{
			for (int x = left; x < right; x++)
			{
				const byte* pixel = V_FindTransformedFlatPixel(x, y, width, src);
				*dest++ = *pixel;
			}

			dest += surface_advance;
		}
	}
	else
	{
		argb_t* dest = (argb_t*)mSurface->getBuffer() + top * mSurface->getPitchInPixels() + left;

		for (int y = top; y < bottom; y++)
		{
			for (int x = left; x < right; x++)
			{
				const byte* pixel = V_FindTransformedFlatPixel(x, y, width, src);
				*dest++ = V_Palette.shade(*pixel);
			}

			dest += surface_advance;
		}
	}
}


// [SL] Stretches a patch to fill the full-screen while maintaining a 4:3
// aspect ratio. Pillarboxing is used in widescreen resolutions.
void DCanvas::DrawPatchFullScreen(const patch_t* patch, bool clear) const
{
	if (clear)
		mSurface->clear();

	const int surface_width = mSurface->getWidth(), surface_height = mSurface->getHeight();

	int destw, desth;

	if (I_IsProtectedResolution(I_GetVideoWidth(), I_GetVideoHeight()))
	{
		destw = surface_width;
		desth = surface_height;
	}
	else if (surface_width * 3 >= surface_height * 4)
	{
		destw = surface_height * 4 / 3;
		desth = surface_height;
	}
	else
	{
		destw = surface_width;
		desth = surface_width * 3 / 4;
	}

	const int width = patch->width();

	if (width > 320)
		destw = surface_width;

	const int x = (surface_width - destw) / 2;
	const int y = (surface_height - desth) / 2;

	// Dim everything before drawing the patch.
	mSurface->getDefaultCanvas()->Dim(0, 0, I_GetVideoWidth(), I_GetVideoHeight());

	DrawPatchStretched(patch, x, y, destw, desth);
}


// [RH] Set an area to a specified color
void DCanvas::Clear(int left, int top, int right, int bottom, argb_t color) const
{
	const int surface_pitch_pixels = mSurface->getPitchInPixels();

	if (mSurface->getBitsPerPixel() == 8)
	{
		const palindex_t color_index = V_BestColor(V_GetDefaultPalette()->basecolors, color);
		palindex_t* dest = (palindex_t*)mSurface->getBuffer() + top * surface_pitch_pixels + left;

		const int line_length = (right - left) * sizeof(palindex_t);
		for (int y = top; y < bottom; y++)
		{
			memset(dest, color_index, line_length);
			dest += surface_pitch_pixels;
		}
	}
	else
	{
		color = V_GammaCorrect(color);
		argb_t* dest = (argb_t*)mSurface->getBuffer() + top * surface_pitch_pixels + left;

		for (int y = top; y < bottom; y++)
		{
			for (int x = 0; x < right - left; x++)
				dest[x] = color;
			dest += surface_pitch_pixels;
		}
	}
}

/**
 * @brief Draw a line between two points.
 *
 * @detail Yet another implementation of Bresenham.
 *
 * @param src Source point.
 * @param dst Destination point.
 * @param color Color to paint the line.
*/
void DCanvas::Line(const v2int_t src, const v2int_t dst, argb_t color) const
{
	const palindex_t pal_color = V_BestColor(V_GetDefaultPalette()->basecolors, color);
	const argb_t full_color = V_GammaCorrect(color);

	const int dx = abs(dst.x - src.x), sx = src.x < dst.x ? 1 : -1;
	const int dy = -abs(dst.y - src.y), sy = src.y < dst.y ? 1 : -1;

	int err = dx + dy;

	v2int_t cur(src);

	for (;;)
	{
		if (mSurface->getBitsPerPixel() == 8)
		{
			palindex_t* dest = (palindex_t*)mSurface->getBuffer(cur.x, cur.y);
			*dest = pal_color;
		}
		else
		{
			argb_t* dest = (argb_t*)mSurface->getBuffer(cur.x, cur.y);
			*dest = full_color;
		}

		if (cur.x == dst.x && cur.y == dst.y)
			break;

		const int e2 = 2 * err;
		if (e2 >= dy)
		{
			err += dy;
			cur.x += sx;
		}

		if (e2 <= dx)
		{
			err += dx;
			cur.y += sy;
		}
	}
}

/**
 * @brief Draw an empty box according to a rectangle.
 *
 * @param bounds Boundary of the rectangle, inclusive.
 * @param color Color of the rectangle.
 */
void DCanvas::Box(const rectInt_t& bounds, const argb_t color) const
{
	const v2int_t topRight(bounds.max.x, bounds.min.y);
	const v2int_t botLeft(bounds.min.x, bounds.max.y);
	Line(bounds.min, topRight, color);
	Line(topRight, bounds.max, color);
	Line(bounds.min, botLeft, color);
	Line(botLeft, bounds.max, color);
}

EXTERN_CVAR (ui_dimamount)
EXTERN_CVAR (ui_dimcolor)

void DCanvas::Dim(int x1, int y1, int w, int h, const char* color_str, float famount) const
{
	const int surface_width = mSurface->getWidth(), surface_height = mSurface->getHeight();
	const int surface_pitch_pixels = mSurface->getPitchInPixels();

	if (x1 < 0 || x1 + w > surface_width || y1 < 0 || y1 + h > surface_height)
		return;

	if (famount <= 0.0f)
		return;
	else if (famount > 1.0f)
		famount = 1.0f;

	if (mSurface->getBitsPerPixel() == 8)
	{
		int bg;
		int x, y;

		const int amount = (int)(famount * 64.0f);
		const argb_t *fg2rgb = Col2RGB8[amount];
		const argb_t *bg2rgb = Col2RGB8[64-amount];

		const argb_t color = V_GetColorFromString(color_str);
		const unsigned int fg = fg2rgb[V_BestColor(V_GetDefaultPalette()->basecolors, color)];

		palindex_t* dest = (palindex_t*)mSurface->getBuffer() + y1 * surface_pitch_pixels + x1;
		const int advance = surface_pitch_pixels - w;

		const int xcount = w / 4;
		const int xcount_remainder = w % 4;

		for (y = h; y > 0; y--)
		{
			for (x = xcount; x > 0; x--)
			{
				// Unroll the loop for a speed improvement
				bg = bg2rgb[*dest];
				bg = (fg+bg) | 0x1f07c1f;
				*dest++ = RGB32k[0][0][bg&(bg>>15)];

				bg = bg2rgb[*dest];
				bg = (fg+bg) | 0x1f07c1f;
				*dest++ = RGB32k[0][0][bg&(bg>>15)];

				bg = bg2rgb[*dest];
				bg = (fg+bg) | 0x1f07c1f;
				*dest++ = RGB32k[0][0][bg&(bg>>15)];

				bg = bg2rgb[*dest];
				bg = (fg+bg) | 0x1f07c1f;
				*dest++ = RGB32k[0][0][bg&(bg>>15)];
			}
			for (x = xcount_remainder; x > 0; x--)
			{
				// account for widths that aren't multiples of 4
				bg = bg2rgb[*dest];
				bg = (fg+bg) | 0x1f07c1f;
				*dest++ = RGB32k[0][0][bg&(bg>>15)];
			}
			dest += advance;
		}
	}
	else
	{
		const argb_t color = V_GammaCorrect(V_GetColorFromString(color_str));

		r_dimpatchD(mSurface, color, (int)(famount * 256.0f), x1, y1, w, h);
	}
}

void DCanvas::Dim(int x1, int y1, int w, int h) const
{
	if (ui_dimamount < 0.0f)
		ui_dimamount.Set (0.0f);
	else if (ui_dimamount > 1.0f)
		ui_dimamount.Set (1.0f);

	if (ui_dimamount == 0.0f)
		return;

	Dim(x1, y1, w, h, ui_dimcolor.cstring(), ui_dimamount);
}

// Build the tables necessary for translucency
static void BuildTransTable(const argb_t* palette_colors)
{
	// create the small RGB table
	for (int r = 0; r < 32; r++)
		for (int g = 0; g < 32; g++)
			for (int b = 0; b < 32; b++)
				RGB32k[r][g][b] = V_BestColor(palette_colors, (r<<3)|(r>>2), (g<<3)|(g>>2), (b<<3)|(b>>2));

	for (int x = 0; x < 65; x++)
		for (int y = 0; y < 256; y++)
			Col2RGB8[x][y] = (((palette_colors[y].getr() * x) >> 4) << 20)  |
							  ((palette_colors[y].getg() * x )>> 4) |
							 (((palette_colors[y].getb() * x) >> 4) << 10);
}


VERSION_CONTROL (v_video_cpp, "$Id: c01565ae511c254df8db3526602645257508024c $")
