Fixed point gamedev

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WebFeb 22, 2024 · I understand that floating point math is not consistent from CPU to CPU, so saving inputs with frame counters won't give you stable replays. I saw someone mention that fixed point math is a possible solution, so I'm currently working on a C++ engine using Libfixmath fix16_t datatypes in place of anything that would be a floating point. Webfixed-point: [adjective] involving or being a mathematical notation (as in a decimal system) in which the point separating whole numbers and fractions is fixed — compare floating …

C++11 Fixed Point Arithmetic Library - Embedded Artistry

WebMar 29, 2008 · GameDev.net is your resource for game development with forums, tutorials, blogs, projects, portfolios, news, and more. ... When using fixed-point number one frame took cca 15ms and when using floats one frame took cca 25ms, so there is a difference, but on PC the difference was negligible. Also, compiling with fixed-point numbers the code … WebMar 13, 2013 · Fixed Point data still might have its uses to minimize memory storage space. As long as the conversions are not done constantly (and obviously one or two bytes are enough of a range for the values needed.) Example - for bone animations angles being applied with individual bones getting target angles and rates/time periods to Tween … check large images plugin wordpress

Fixed-Point VS. Floating point - Math and Physics - GameDev.net

WebJan 11, 2011 · C++ conversion from a floating point type to a integral type is well-defined as long as the value in the floating point type fits inside the range of the integral type: it always truncates (discards the fractional part). If the value doesn't fit inside the range of the integral type the behavior is undefined. WebJun 30, 2024 · It's is possible to simulate floating- or fixed-point math, you just have to write all logic yourself (or use library). The only limits are your creativity and resulting … check largest files windows

$Determinism with fixed point math : gamedev - reddit$

Does anyone use fixed point math anymore? - GameDev.net

WebMar 29, 2008 · GameDev.net is your resource for game development with forums, tutorials, blogs, projects, portfolios, news, and more. IMHO the fixed-point operations would be slower on today's computers because floats are now really fast. Or there will be almost no difference. It is not worth the trouble with overflows and underflows.It could be useful on ... WebI need fixed-point math because I'd like to have deterministic results, for reproducibility purposes, and high portability, because I expect my game to be highly portable for … check large files windowsWebJul 7, 2004 · I'm not trying to figure out the arctan of a fixed point, but rather trying to develop a function to find the arc tangent of y/x much like the C function in the Math.h library atan2(y,x). I am developing this function using fixed point arithmetic, ie. no decimals (floating point values). fl assignee\u0027s

"WebDec 18, 2006 · Fixed Point or Integer, doesnt matter. A double precision value has 53 bits of mantissa (52 actual, 1 implied), not 58. The x87 class FPU performs calculations with 80-bit "extended double precision" which has a 64-bit mantissa (63 actual, 1 implied) unless you play with the FPU rounding state. " - Fixed point gamedev

Fixed point gamedev

WebMar 20, 2004 · How to do fixed point math. 1) Choose where the decimal should be. Remember, computers work in binary, so this should always be a power of two. 2) To convert a float to a fixed point number, mulitply by #1. 3) Since you picked a power of two, there is a shortcut for converting ints to fixed point numbers. WebNov 18, 2013 · translation.applyTo (pointToRotate) pointToRotate.rotate (angle) translation *= -1. translation.applyTo (pointToRotate) This would result in rotating around a fixed point but i want to change the radius of rotation, in this case the radius would be distance from a given point to the point with respect to which the object is rotating. Thanks all ...

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WebMar 12, 2013 · Fixed-point is more natural for certain situations, like representing the position of an object in a huge world You dont even need fixed point for this. Just never store vertices in world space. Keep your models each in their own coordinate system near 0,0,0. No, that will not solve the issue. WebOct 11, 2024 · To rotate it with timestep dt, you would do: angle += dt * angular_velocity body.up.x = cosf ( angle ) body.up.y = sinf ( angle ) body.pos.x = centre.x + radius * body.up.x body.pos.y = centre.y + radius * body.up.y. Note that instead of defining the body's rotation with an up-vector, you could use an x-vector, or even just an angle, which …

Web2. C++ Fast-track for Games Programming Part 14: Fixed Point. In part Part 9 you worked with colours and were introduced to the noble art of bitmagic. Here’s a quick refresher: … WebMar 24, 2024 · Add a comment. -1. move_towards_point makes the object move towards a particular point - as its name implies. If the object is at coordinates 200,200 and you do move_towards_point (x, -y, 10) then …

WebOct 25, 2003 · I''m trying to do a square root operation on a 8.8 16-bit value. (ie. top byte is 2^7 .. 2^0 and bottomn byte is 2^-1 .. 2^-8) I have a function to do a SQRT on an integer. … WebWith the regular authoritative server model, the game server simulates the game and sends state updates to clients. This becomes infeasible if you have many entities. However, with the lockstep technique each client …

WebJul 7, 2004 · The context in which you need such advanced math in fixed point and the bits of precision required would help. Anyway there are 4 tracks that might guide you : - lut (look up tables) can surely boost fixed point since many muls and divs are not welcome. - Taylor series or Newton-Raphson like technics (based on limited developments).

WebI need fixed-point math because I'd like to have deterministic results, for reproducibility purposes, and high portability, because I expect my game to be highly portable for devices such as mobile phones or portable gaming consoles without floating point units. physics physics-engine Share Improve this question Follow asked Feb 15, 2011 at 22:00 flassh photo booth softwareWebAug 26, 2024 · I recently stumbled across a C ++11 fixed_point header-only library that supports fixed-point mathematical operations. The library introduces a fixed_point … check largest folder size windowsWebChanging fixed point representations is commonly called 'scaling'. If you can do this with a class with no performance penalty, then that's the way to go. It depends heavily on the … flass houseWebJul 22, 2024 · Jul 24, 2024 at 3:27. @bobuhito: There are options for making long double be 80-bit in C with GCC, I think, but you'd need a way to get an fsqrt instruction inlined, … flassh s2 watch onlineWebJun 14, 2006 · Another practical use for fixed point is when data must be synchronized on multiple machines across a network. Say you're doing a multiplayer game and each machine broadcasts a set of values over the network and then every other machine needs to compute the exact same derived values from them. check larosa\\u0027s gift card balanceWebEven the tiniest differences would accumulate over time and cause problems. Unfortunately, achieving full cross-platform determinism is not easy. Read the full article to learn how I went on to solve the problem … flass house durhamWebOct 14, 1999 · Your choice of fixed point formats is restricted by your choice of programming language. If you pick a 32 bit fixed point format like 16.16 then you need to be able to multiply two 32 bit numbers, get a 64 bit result, and then shift the result right to get it back into the original fixed point format. flass house maulds meaburn