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GCC Code Coverage Report

Directory:	src/		Exec	Total	Coverage
File:	src/sdl2gfx/SDL2_framerate.cpp	Lines:	9	35	25.7 %
Date:	2021-03-17	Branches:	2	20	10.0 %


/*

SDL2_framerate.c: framerate manager

Copyright (C) 2012-2014  Andreas Schiffler

This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.

2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.

3. This notice may not be removed or altered from any source
distribution.

Andreas Schiffler -- aschiffler at ferzkopp dot net

Changed for ManaPlus (C) 2013-2017  ManaPlus developers

*/

#include "sdl2gfx/SDL2_framerate.h"

#include "debug.h"

/*!
\brief Internal wrapper to SDL_GetTicks that ensures a non-zero return value.

\return The tick count.
*/
static Uint32 _getTicks()
{
    Uint32 ticks = SDL_GetTicks();

    /*
    * Since baseticks!=0 is used to track initialization
    * we need to ensure that the tick count is always >0
    * since SDL_GetTicks may not have incremented yet and
    * return 0 depending on the timing of the calls.
    */
    if (ticks == 0)
    {
        return 1;
    }
    else
    {
        return ticks;
    }
}

/*!
\brief Initialize the framerate manager.

Initialize the framerate manager, set default framerate of 30Hz and
reset delay interpolation.

\param manager Pointer to the framerate manager.
*/
void SDL_initFramerate(FPSmanager * manager)
{
    /*
    * Store some sane values
    */
    manager->framecount = 0;
    manager->rate = FPS_DEFAULT;
    manager->rateticks = (1000.0F / static_cast<float>(FPS_DEFAULT));
    manager->baseticks = _getTicks();
    manager->lastticks = manager->baseticks;

}

/*!
\brief Set the framerate in Hz

Sets a new framerate for the manager and reset delay interpolation.
Rate values must be between FPS_LOWER_LIMIT and FPS_UPPER_LIMIT inclusive to be accepted.

\param manager Pointer to the framerate manager.
\param rate The new framerate in Hz (frames per second).

\return 0 for sucess and -1 for error.
*/
int SDL_setFramerate(FPSmanager * manager, Uint32 rate)
{
    if ((rate >= FPS_LOWER_LIMIT) && (rate <= FPS_UPPER_LIMIT))
    {
        manager->framecount = 0;
        manager->rate = rate;
        manager->rateticks = (1000.0F / static_cast<float>(rate));
        return (0);
    }
    else
    {
        return (-1);
    }
}

/*!
\brief Return the current target framerate in Hz

Get the currently set framerate of the manager.

\param manager Pointer to the framerate manager.

\return Current framerate in Hz or -1 for error.
*/
int SDL_getFramerate(FPSmanager * manager)
{
    if (manager == nullptr)
    {
        return (-1);
    }
    else
    {
        return (static_cast<int>(manager->rate));
    }
}

/*!
\brief Return the current framecount.

Get the current framecount from the framerate manager.
A frame is counted each time SDL_framerateDelay is called.

\param manager Pointer to the framerate manager.

\return Current frame count or -1 for error.
*/
int SDL_getFramecount(FPSmanager * manager)
{
    if (manager == nullptr)
    {
        return (-1);
    }
    else
    {
        return (static_cast<int>(manager->framecount));
    }
}

/*!
\brief Delay execution to maintain a constant framerate and calculate fps.

Generate a delay to accomodate currently set framerate. Call once in the
graphics/rendering loop. If the computer cannot keep up with the rate (i.e.
drawing too slow), the delay is zero and the delay interpolation is reset.

\param manager Pointer to the framerate manager.

\return The time that passed since the last call to the function in ms. May return 0.
*/
Uint32 SDL_framerateDelay(FPSmanager * manager)
{
    Uint32 current_ticks;
    Uint32 target_ticks;
    Uint32 the_delay;
    Uint32 time_passed = 0;

    /*
    * No manager, no delay
    */
    if (manager == nullptr)
    {
        return 0;
    }

    /*
    * Initialize uninitialized manager
    */
    if (manager->baseticks == 0)
    {
        SDL_initFramerate(manager);
    }

    /*
    * Next frame
    */
    manager->framecount++;

    /*
    * Get/calc ticks
    */
    current_ticks = _getTicks();
    time_passed = current_ticks - manager->lastticks;
    manager->lastticks = current_ticks;
    target_ticks = manager->baseticks + static_cast<Uint32>(static_cast<float>(
        manager->framecount) * manager->rateticks);

    if (current_ticks <= target_ticks)
    {
        the_delay = target_ticks - current_ticks;
        SDL_Delay(the_delay);
    }
    else
    {
        manager->framecount = 0;
        manager->baseticks = _getTicks();
    }

    return time_passed;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/*
2
3			SDL2_framerate.c: framerate manager
4
5			Copyright (C) 2012-2014 Andreas Schiffler
6
7			This software is provided 'as-is', without any express or implied
8			warranty. In no event will the authors be held liable for any damages
9			arising from the use of this software.
10
11			Permission is granted to anyone to use this software for any purpose,
12			including commercial applications, and to alter it and redistribute it
13			freely, subject to the following restrictions:
14
15			1. The origin of this software must not be misrepresented; you must not
16			claim that you wrote the original software. If you use this software
17			in a product, an acknowledgment in the product documentation would be
18			appreciated but is not required.
19
20			2. Altered source versions must be plainly marked as such, and must not be
21			misrepresented as being the original software.
22
23			3. This notice may not be removed or altered from any source
24			distribution.
25
26			Andreas Schiffler -- aschiffler at ferzkopp dot net
27
28			Changed for ManaPlus (C) 2013-2017 ManaPlus developers
29
30			*/
31
32			#include "sdl2gfx/SDL2_framerate.h"
33
34			#include "debug.h"
35
36			/*!
37			\brief Internal wrapper to SDL_GetTicks that ensures a non-zero return value.
38
39			\return The tick count.
40			*/
41			static Uint32 _getTicks()
42			{
43			Uint32 ticks = SDL_GetTicks();
44
45			/*
46			* Since baseticks!=0 is used to track initialization
47			* we need to ensure that the tick count is always >0
48			* since SDL_GetTicks may not have incremented yet and
49			* return 0 depending on the timing of the calls.
50			*/
51			if (ticks == 0)
52			{
53			return 1;
54			}
55			else
56			{
57			return ticks;
58			}
59			}
60
61			/*!
62			\brief Initialize the framerate manager.
63
64			Initialize the framerate manager, set default framerate of 30Hz and
65			reset delay interpolation.
66
67			\param manager Pointer to the framerate manager.
68			*/
69			void SDL_initFramerate(FPSmanager * manager)
70			{
71			/*
72			* Store some sane values
73			*/
74			manager->framecount = 0;
75			manager->rate = FPS_DEFAULT;
76			manager->rateticks = (1000.0F / static_cast<float>(FPS_DEFAULT));
77			manager->baseticks = _getTicks();
78			manager->lastticks = manager->baseticks;
79
80			}
81
82			/*!
83			\brief Set the framerate in Hz
84
85			Sets a new framerate for the manager and reset delay interpolation.
86			Rate values must be between FPS_LOWER_LIMIT and FPS_UPPER_LIMIT inclusive to be accepted.
87
88			\param manager Pointer to the framerate manager.
89			\param rate The new framerate in Hz (frames per second).
90
91			\return 0 for sucess and -1 for error.
92			*/
93		2	int SDL_setFramerate(FPSmanager * manager, Uint32 rate)
94			{
95	✓✗	2	if ((rate >= FPS_LOWER_LIMIT) && (rate <= FPS_UPPER_LIMIT))
96			{
97		2	manager->framecount = 0;
98		2	manager->rate = rate;
99		2	manager->rateticks = (1000.0F / static_cast<float>(rate));
100		2	return (0);
101			}
102			else
103			{
104			return (-1);
105			}
106			}
107
108			/*!
109			\brief Return the current target framerate in Hz
110
111			Get the currently set framerate of the manager.
112
113			\param manager Pointer to the framerate manager.
114
115			\return Current framerate in Hz or -1 for error.
116			*/
117		3	int SDL_getFramerate(FPSmanager * manager)
118			{
119	✓✗	3	if (manager == nullptr)
120			{
121			return (-1);
122			}
123			else
124			{
125		3	return (static_cast<int>(manager->rate));
126			}
127			}
128
129			/*!
130			\brief Return the current framecount.
131
132			Get the current framecount from the framerate manager.
133			A frame is counted each time SDL_framerateDelay is called.
134
135			\param manager Pointer to the framerate manager.
136
137			\return Current frame count or -1 for error.
138			*/
139			int SDL_getFramecount(FPSmanager * manager)
140			{
141			if (manager == nullptr)
142			{
143			return (-1);
144			}
145			else
146			{
147			return (static_cast<int>(manager->framecount));
148			}
149			}
150
151			/*!
152			\brief Delay execution to maintain a constant framerate and calculate fps.
153
154			Generate a delay to accomodate currently set framerate. Call once in the
155			graphics/rendering loop. If the computer cannot keep up with the rate (i.e.
156			drawing too slow), the delay is zero and the delay interpolation is reset.
157
158			\param manager Pointer to the framerate manager.
159
160			\return The time that passed since the last call to the function in ms. May return 0.
161			*/
162			Uint32 SDL_framerateDelay(FPSmanager * manager)
163			{
164			Uint32 current_ticks;
165			Uint32 target_ticks;
166			Uint32 the_delay;
167			Uint32 time_passed = 0;
168
169			/*
170			* No manager, no delay
171			*/
172			if (manager == nullptr)
173			{
174			return 0;
175			}
176
177			/*
178			* Initialize uninitialized manager
179			*/
180			if (manager->baseticks == 0)
181			{
182			SDL_initFramerate(manager);
183			}
184
185			/*
186			* Next frame
187			*/
188			manager->framecount++;
189
190			/*
191			* Get/calc ticks
192			*/
193			current_ticks = _getTicks();
194			time_passed = current_ticks - manager->lastticks;
195			manager->lastticks = current_ticks;
196			target_ticks = manager->baseticks + static_cast<Uint32>(static_cast<float>(
197			manager->framecount) * manager->rateticks);
198
199			if (current_ticks <= target_ticks)
200			{
201			the_delay = target_ticks - current_ticks;
202			SDL_Delay(the_delay);
203			}
204			else
205			{
206			manager->framecount = 0;
207			manager->baseticks = _getTicks();
208			}
209
210			return time_passed;
211			}