scummvm/engines/saga2/gamerate.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 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.
 *
 * You should have received a copy of the GNU General Public License
 * aint32 with this program; if not, write to the Free Software
 *
 *
 * Based on the original sources
 *   Faery Tale II -- The Halls of the Dead
 *   (c) 1993-1996 The Wyrmkeep Entertainment Co.
 */

#ifndef SAGA2_GAMERATE_H
#define SAGA2_GAMERATE_H

namespace Saga2 {

enum {
	grFramesPerSecond = 0
};

class frameCounter {
	uint32 ticksPerSecond;
	uint32 lastTime;

protected:
	uint32 frames;
	float instantFrameCount;

public:
	frameCounter(uint32 perSec, uint32 now) {
		ticksPerSecond = perSec;
		frames = 0;
		lastTime = now;
		instantFrameCount = 0;
	}

	virtual ~frameCounter() {}

	virtual void updateFrameCount() {
		int32 frameTime = gameTime - lastTime;
		lastTime = gameTime;
		frames++;
		instantFrameCount = frameTime ? ticksPerSecond / frameTime : 100;
	}

	virtual float frameStat(int statID = grFramesPerSecond) {
		return instantFrameCount;
	}

	virtual void whatDoYouKnow(char *buf) {
		sprintf(buf, "FPS: %02.2f", frameStat());
	}

};


enum {
	grFramesPerKilosecond   = 1,
	grFPKS1SecAvgNewest     = 2,
	grFPKS1SecAvgNew        = 3,
	grFPKS1SecAvg           = 4,
	grFPKS1SecAvgOld        = 5,
	grFPKS1SecAvgOldest     = 6,
	grFPKS5SecAvg           = 7,
	grFPKSAvg1SecAvg        = 8,
	grFPKS1SecVarNewest     = 9,
	grFPKS1SecVarNew        = 10,
	grFPKS1SecVar           = 11,
	grFPKS1SecVarOld        = 12,
	grFPKS1SecVarOldest     = 13,
	grFPKS5SecVar           = 14,
	grFPKSVar1SecAvg        = 15
};

class frameSmoother: public frameCounter {
	float desiredFPS;

	uint32 historySize;
	float *frameHistory;

	float avg1Sec[5];
	float avg5Sec;
	float secAvg;
	float dif1Sec[5];
	float dif5Sec;
	float secDif;

	float ksHistory(int32 i) {
		return 1000.0 * frameHistory[i];
	}

	void calculateAverages() {
		// clear averages
		for (int i = 0; i < 5; i++)
			avg1Sec[i] = 0;

		avg5Sec = 0;

		// get totals
		for (uint i = 0; i < historySize; i++)
			avg1Sec[i / int(desiredFPS)] += ksHistory(i);

		// get averages
		for (uint i = 0; i < 5; i++) {
			avg5Sec += avg1Sec[i];
			avg1Sec[i] /= desiredFPS;
		}

		// get broad averages
		secAvg = avg5Sec / 5;
		avg5Sec /= (5 * desiredFPS);
	}

	void calculateVariance() {
		// clear variances
		for (int i = 0; i < 5; i++)
			dif1Sec[i] = 0;

		dif5Sec = 0;

		// get variance totals
		for (uint i = 0; i < historySize; i++) {
			dif1Sec[i / int(desiredFPS)] += ABS(ksHistory(i) - avg1Sec[i / int(desiredFPS)]);
			dif5Sec += ABS(ksHistory(i) - avg5Sec);
		}

		// get average variances
		for (uint i = 0; i < 5; i++) {
			secDif += avg1Sec[i] - secAvg;
			dif1Sec[i] /= desiredFPS;
		}

		// get broad variance
		dif5Sec /= (5 * desiredFPS);
	}


public:
	frameSmoother(int32 fps, uint32 perSec, uint32 now);


	virtual ~frameSmoother() {
		if (frameHistory)
			delete[] frameHistory;

		frameHistory = nullptr;
	}

	virtual void updateFrameCount() {
		frameCounter::updateFrameCount();
		frameHistory[frames % historySize] = instantFrameCount;
		if (0 == (frames % int(desiredFPS))) {
			calculateAverages();
			calculateVariance();
		}
	}

	virtual float frameStat(int statID = grFramesPerSecond) {
		int oldestOffset = (frames % historySize) / desiredFPS;
		switch (statID) {
		case grFramesPerKilosecond  :
			return 1000 * instantFrameCount;
		case grFPKS1SecAvgNewest    :
			return avg1Sec[4 + oldestOffset];
		case grFPKS1SecAvgNew       :
			return avg1Sec[3 + oldestOffset];
		case grFPKS1SecAvg          :
			return avg1Sec[2 + oldestOffset];
		case grFPKS1SecAvgOld       :
			return avg1Sec[1 + oldestOffset];
		case grFPKS1SecAvgOldest    :
			return avg1Sec[0 + oldestOffset];
		case grFPKS5SecAvg          :
			return avg5Sec;
		case grFPKSAvg1SecAvg       :
			return secAvg;
		case grFPKS1SecVarNewest    :
			return dif1Sec[4 + oldestOffset];
		case grFPKS1SecVarNew       :
			return dif1Sec[3 + oldestOffset];
		case grFPKS1SecVar          :
			return dif1Sec[2 + oldestOffset];
		case grFPKS1SecVarOld       :
			return dif1Sec[1 + oldestOffset];
		case grFPKS1SecVarOldest    :
			return dif1Sec[0 + oldestOffset];
		case grFPKS5SecVar          :
			return dif5Sec;
		case grFPKSVar1SecAvg       :
			return secDif;
		default:
			return frameCounter::frameStat(statID);
		}
	}

	virtual void whatDoYouKnow(char *buf) {
		float f[15];
		for (int i = 0; i < 15; i++) {
			f[i] = MAX((float) -99, MIN((float)99, (float)(((float) frameStat(i + 1)) / ((float) 1000))));
		}
		sprintf(buf, "Imm: %02.2f  1 Sec %02.2f | %02.2f  5 Sec %02.2f | %02.2f"
		        //"  -(%2.2f  %2.2f  %2.2f,%2.2f,%2.2f,%2.2f,%2.2f)",
		        , f[0],  f[1], f[8], f[6], f[13]);
		//, f[3], f[4], f[5],
		//                  f[13],f[14], f[8],f[9],f[10],f[11],f[12]);
	}
};

frameSmoother::frameSmoother(int32 fps, uint32 perSec, uint32 now)
	: frameCounter(perSec, now) {
	assert(fps);
	desiredFPS = fps;
	historySize = fps * 5;
	frameHistory = new float[historySize];

	for (uint32 i = 0; i < historySize; i++)
		frameHistory[i] = 0;

	for (int i = 0; i < 5; i++)
		dif1Sec[i] = avg1Sec[i] = 0;

	dif5Sec = 0;
	avg5Sec = 0;
	secDif = 0;
	secAvg = 0;
}

} // end of namespace Saga2

#endif