summaryrefslogtreecommitdiffstats
path: root/src/vehicles/Transmission.cpp
blob: d500d004feab12e2a1ee46437d17b941d972b7af (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
#include "common.h"
#include "patcher.h"
#include "Timer.h"
#include "HandlingMgr.h"
#include "Transmission.h"

void
cTransmission::InitGearRatios(void)
{
	static tGear *pGearRatio0 = nil;
	static tGear *pGearRatio1 = nil;
	int i;
	float velocityDiff;

	memset(Gears, 0, sizeof(Gears));

	for(i = 1; i <= nNumberOfGears; i++){
		pGearRatio0 = &Gears[i-1];
		pGearRatio1 = &Gears[i];

		pGearRatio1->fMaxVelocity = (float)i / nNumberOfGears * fMaxVelocity;

		velocityDiff = pGearRatio1->fMaxVelocity - pGearRatio0->fMaxVelocity;

		if(i >= nNumberOfGears){
			pGearRatio1->fShiftUpVelocity = fMaxVelocity;
		}else{
			Gears[i+1].fShiftDownVelocity = velocityDiff*0.42f + pGearRatio0->fMaxVelocity;
			pGearRatio1->fShiftUpVelocity = velocityDiff*0.6667f + pGearRatio0->fMaxVelocity;
		}
	}

	// Reverse gear
	Gears[0].fMaxVelocity = fMaxReverseVelocity;
	Gears[0].fShiftUpVelocity = -0.01f;
	Gears[0].fShiftDownVelocity = fMaxReverseVelocity;

	Gears[1].fShiftDownVelocity = -0.01f;
}

void
cTransmission::CalculateGearForSimpleCar(float speed, uint8 &gear)
{
	static tGear *pGearRatio;

	pGearRatio = &Gears[gear];
	fCurVelocity = speed;
	if(speed > pGearRatio->fShiftUpVelocity)
		gear++;
	else if(speed < pGearRatio->fShiftDownVelocity){
		if(gear - 1 < 0)
			gear = 0;
		else
			gear--;
	}
}

float
cTransmission::CalculateDriveAcceleration(const float &gasPedal, uint8 &gear, float &time, const float &velocity, bool cheat)
{
	static float fAcceleration = 0.0f;
	static float fVelocity;
	static float fCheat;
	static tGear *pGearRatio;

	fVelocity = velocity;
	if(fVelocity < fMaxReverseVelocity){
		fVelocity = fMaxReverseVelocity;
		return 0.0f;
	}
	if(fVelocity > fMaxVelocity){
		fVelocity = fMaxVelocity;
		return 0.0f;
	}
	fCurVelocity = fVelocity;

	assert(gear <= nNumberOfGears);

	pGearRatio = &Gears[gear];
	if(fVelocity > pGearRatio->fShiftUpVelocity){
		if(gear != 0 || gasPedal > 0.0f){
			gear++;
			time = 0.0f;
			return CalculateDriveAcceleration(gasPedal, gear, time, fVelocity, false);
		}
	}else if(fVelocity < pGearRatio->fShiftDownVelocity && gear != 0){
		if(gear != 1 || gasPedal < 0.0f){
			gear--;
			time = 0.0f;
			return CalculateDriveAcceleration(gasPedal, gear, time, fVelocity, false);
		}
	}

	if(time > 0.0f){
		// changing gears currently, can't accelerate
		fAcceleration = 0.0f;
		time -= CTimer::GetTimeStepInSeconds();
	}else{
		float speedMul, accelMul;

		if(gear < 1){
			// going reverse
			accelMul = (Flags & HANDLING_2G_BOOST) ? 2.0f : 1.0f;
			speedMul = -1.0f;
		}else if(nNumberOfGears == 1){
			accelMul = 1.0f;
			speedMul = 1.0f;
		}else{
			// BUG or not? this is 1.0 normally but 0.0 in the highest gear
			float f = 1.0f - (gear-1)/(nNumberOfGears-1);
			speedMul = 3.0f*sq(f) + 1.0f;
			// This is pretty ugly, could be written more clearly
			if(Flags & HANDLING_2G_BOOST){
				if(gear == 1)
					accelMul = (Flags & HANDLING_1G_BOOST) ? 3.0f : 2.0f;
				else if(gear == 2)
					accelMul = 1.3f;
				else
					accelMul = 1.0f;
			}else if(Flags & HANDLING_1G_BOOST && gear == 1){
				accelMul = 3.0f;
			}else
				accelMul = 1.0f;
		}

		if(cheat)
			fCheat = 1.2f;
		else
			fCheat = 1.0f;
		float targetVelocity = Gears[gear].fMaxVelocity*speedMul*fCheat;
		float accel = fEngineAcceleration*accelMul * (targetVelocity - fVelocity)/Abs(targetVelocity);
		if(Abs(fVelocity) < Abs(Gears[gear].fMaxVelocity*fCheat))
			fAcceleration = gasPedal * accel * CTimer::GetTimeStep();
		else
			fAcceleration = 0.0f;
	}
	return fAcceleration;
}

STARTPATCHES
	InjectHook(0x550A00, &cTransmission::CalculateGearForSimpleCar, PATCH_JUMP);
	InjectHook(0x5506B0, &cTransmission::CalculateDriveAcceleration, PATCH_JUMP);
ENDPATCHES