Glsl round float to int. without having to convert the number to a numeric type .

Glsl round float to int Casting from a float to an integer will round the float towards zero. When you have a specialization constant and perform some operation on it In WebGL2 you can pass integer data and do integer math (signed and unsigned) in shaders. Perhaps you mean packing an arbitrary 32-bit value into a float? You can use the builtin intBitsToFloat to copy 32 bits from an int to a float in a bitwise manner. 30 can implicitly convert integers to floats, but it will not implicitly convert floats to ints. Related: Algorithm for finding the smallest power of two that's greater or equal to a given value is a C++ question. First way is floor rounding the float value: float myFloat = 3. Channel could be lowp or mediump. Commented Apr 10, 2018 at 2:01. To get the behavior your expect, try: int n = floor((4. ret round(x) Parameters. round up: number=sign(number)*ceil(abs(number)); round I want the GLSL equivalent of: float f; int i = *(int *)&f; Any way to do this? Prefer std method but dirty hacks OK. If you are sure the numerals have at most two digits and are of moderate magnitude' reading them as double, multiplying by 100, and rounding to the nearest integer will produce the correct result. This function is You cannot typecast in glsl. How to round an decimal Related: Algorithm for finding the smallest power of two that's greater or equal to a given value is a C++ question. I do not want to round to the the nearest number, I simply want to eliminate what is after the integer part. var a = 12. float roundParam_v2(float val, float dir) { union fl_i32{float f; int i;} x, y, d; x. Commented Apr 10, 2018 at I want the GLSL equivalent of: float f; int i = *(int *)&f; Any way to do this? Prefer std method but dirty hacks OK. 255. I need to convert a float number into an int. 7) # 2 Share. Follow edited Apr 23, 2014 at 15:20. f = val; d. – Gnietschow. which would return integers of 25 and 26 respectively. Also The only reason for core 420 was the use of arrays I do not know from which version they added them into GLSL but in that it works so I left it as is This remains valid in GLSL 4. genpfault. Also I tried making an array of floats and using the int as an index but that didn't work either! The exact wording from GL 4. Example: It appears at one point in time Nvidia had an extension that permitted half floating point values for OpenGL 1. I'm trying to write a shader which renders a multitextured geometry wihout rerendering the geometry with each texture. johnkslang added bug HLSL labels Mar 20, 2017. x happens to be a float number, the value comes from the mouse X coordinates and well the rest is a vec3. Otherwise, the bit-level representation is preserved. 5'::numeric::integer AS num2. Improve this question . Cast the new value to a new int variable so the unwanted float bits are discarded. Reinterpret bits cast float ->int in GLSL. answered Jun 21, 2014 at 15:06. You could also 'bump' the literal number, to ensure that it won't get truncated (eg. Note though that for an IEEE754 double, all values over the 52nd power of 2 are integral values!A corollary of that is that your I tried Arjans solution, but it returned invalid values for 0, 1, 2, 4. trunc. C++20 introduced std:bit_ceil which lets the compiler do whatever's optimal for the target system, but nothing equivalent is yet available in portable ISO C for bit-scan, popcount or other common bit operations that most CPUs have. i = x. See Also GLSL intBitsToFloat man page GLSL 4. So if I want to get 34 back exactly in my shader, can I trust either of int X1 = round(X255. 5 = 12. I've tried converting the returned float to an int using parsteInt, Math. Then, you can associate that buffer object with the MyBlock uniform block. Ask Question Asked 9 years, 10 months ago. My attempt se As long the float packed with packColor is not in the [0, 1] range but in the [0, 16777215] range, you shouldn't have any problem with precision. Floats can also be defined using exponential notation, using the e or E to separate the base from the exponent. VertexAttribPointer(index, 4, VertexAttribPointerType. Is there a simple effect way to do something like 2. )What we really need is for opengl to multiply by 256 to store the octet as integer and divide by 256 to restore it. Turns out I could have figured this out much more quickly if I'd checked the shader program's info If you want to convert a float value into an integer value, you have several ways to do it that depends on how do you want to round the float value. The shader would, of course, receive the 32 bit float. The x parameter, rounded to the nearest integer within a floating-point type. 0 I want to pack 2 signed float values into alpha channel. Also, check the errors of your OpenGL Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Obviously, not javascript and python because they don't support 32 bit floats. – kyasbal. 34. round() for that. com. bind() does. Returns a floating-point value corresponding to a unsigned integer encoding of a floating-point value. Commented Dec 3, So I want to round down, add half a pixel (I excluded this for simplicity) and convert back into texture coordinates between 0-1. Follow edited @Hofstad is correct with the math. Only problem is that I'd rather have exact integer look-up instead of a floating point texture coordinate. Something like 4. The reason you want to round is because floats are usually approximate. when I make it into a float it does work and everything is fine. It further says: When an implicit conversion is done, it is the same conversion that would be done under explicit conversion, using a constructor. 5 will round in a direction chosen by the implementation, presumably the direction that is fastest. when accessing arrays) Mar 20, 2017. You must declare your uniform in the vertex shader like this: uniform float Test; Also, you have to call glUseProgram() with your program object handle before calling glUniform1f(), so make sure that's what your shader. 3, same section, and behaves as follows: "When a constructor is used to convert a bool to any integer or floating-point type, false is converted to 0 or 0. round, but it is as simple as math. 4 - GLSL Operators (Mathematical and Logical)¶ GLSL is designed for efficient vector and matrix processing. Commented Feb 18, 2016 at 23:11. If you pass an unsigned byte as an integer vertex attribute to a vertex shader, then it can read it as a uint type, which is 32-bits in size. Popularity 8/10 Helpfulness 4/10 Language whatever. In GLSL 4. About; Convert floating-point numbers to decimal digits in GLSL. Rounding numbers in javascript. Conversion and Scalar Constructors. 1), HLSL and Metal Shading Language (Chapter 2. – Tim. For each bit counted, add 1 to the exponent. You can use one of those methods to exactly control what happens instead of relying on the cast. The following is an implementation 1: Make sure your if statement is within a function. It works even if I replace u_time in expression with direct float constant, for example 1563854457241. (Less positive or more negative). 34; now on y. round which basically turns it into an int, meaning 2. Is there a function to round numbers to the nearest integer or would i have to define it my self like this: class Float def to_nearest_i (self+0. f = dir; d. I need this for my postprocessing/resolve pass, so I think pack/unpack overhead will be worth it. The first set (exact halves rounding to small integers) always round to an even integer. i; /* multiply ret round(x) Parameters. GLSL round man page GLSL 4. 0) ). But this might not work because it's not always possible to store decimal numbers exactly as a binary number. Modified 4 years ago. Some of the resulting float values may be NaNs, which might not remain unchanged in certain operations, such as conversion for printing or display and conversion back. The fact that it says “cast” says nothing about rounding vs. But sadly GLSL compilers tend to have bugs and behave in unpredictable ways. In WebGL1 you really get floats and even things marked as an int may actually not be ints. From the precision range of these two data types, we know that for high and medium precision, integer variables can be converted to floating point variables with the same precision modifier. Round(precise, 0) would equal (int)precise, right? I imagine a simpler and safer solution would be to simply use int rounded = (int)(precise+. Because you must truncate the decimal part before typecasting it: i = Int(trunc(1. I've a You would be better suited casting the columns that were text, to numeric, to integer, so that rounding is taken into consideration e. 0); int X2 = int(X255. One way to avoid this problem is to use the Decimal as stated by this answer. Today I can use 16bit floating point values in CUDA no problem, there should not be an issue in hardware for NVIDIA to support 16bit floats, and they To create a float literal from an integer value, use the suffix f or F as in C/C++. As an input value to one of the processing units, a single-precision or double-precision floating-point variable is expected to match the corresponding IEEE 754 floating-point definition for precision and dynamic range. Nor does my version seem to have any bit manipulation operators. 3 There is no way to do implicit casts as in C++ for example,in C++, unsigned int a=134217728; // a is 134217728 float b=a; // b is 1. GLSL isn't Java; new int[] is not legitimate GLSL syntax. 20. I would recommend you take floats, and pass floats from your program, since it is very likely that any given GPU uses floats to represent ints. 9) will round to exactly 1. Also, check the errors of your OpenGL Parse float to int in postgresql. r * 255); int g = int(c. I helped implement strict compliance implementations. To test, use printf with the precision (. What really happens when float X = texture2D(TestTex, vec2(0. But the 32-bit “single precision” floating point format uses some of its bits to represent the exponent and the sign: Description. 3465 # => 2. Issue is texture buffers have one component type. Link to this answer Share Copy Link . Unfortunately if close to the upper edge the interpolated value of fVertexInteger seems to be rounded up instead of beeing floored. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Simply casting to an int truncates the float, which if your system internally represent 2. Some extra info on the technique (using bitwise operators): How to store a 64 bit integer in two 32 bit integers and convert back again. Use casting int normInt = (int)NormValue; but here you have to be prepared that you will loose the decimal points. I believe their is a function for this in glsl called floatBitsToInt, but apparently my version of glsl doesnt have it. Is there a function to round a floating point number directly, i. The best choice is usually nearbyint() (or nearbyintf/l), because it can be done with a single machine instruction on x86 CPUs with SSE4. P. 5; int I = int(f); Bad: float f = 0. I found only round() function, but it is rounding to integer, but I need round number like 0. 3421773e+008 unsigned int a=1; // a is 1 float b=a; // b is 1. 0), like math. mod vs % was just a brain fart. More details can be found here. Is there any way how to round down float to two decimal places? I googled everywhere but without success. 00 and above, double-precision floats are available. The principle you are attempting to use would work (with some adjustment) if you were converting between a 32-bit unsigned integer representation and four 8-bit integers, because there are exactly enough bits to use. I've just grabbed glsl but I'm not sure if I'm doing it Ok. 2: Make sure precision is set before declaring uniforms. 100. Round a float up to the next integer in javascript. user3763109 user3763109. So 4. There are lots of features in GLSL 1. – SPIR-V supports atomic instructions with floating-point types, but SPIR-V modules that contain those are currently forbidden by Vulkan's SPIR-V environment spec: Atomic instructions must declare a scalar 32-bit integer type, or a scalar 64-bit integer type if the Int64Atomics capability is enabled, for the value pointed to by Pointer. 3'::numeric::integer AS num1, '25. clamping. See OpenGL Shading Language 4. When constructors are used to convert a floating-point type to an integer type, the fractional part of the floating-point value is dropped. 9, floored 12 Note that there are also trunc, ceil and floor. That is, it expects you to use float or vec types for the attribute. 4. Zero) and using it in shader as: in vec4 in_color;. There Just like the shader doesn't say that an attribute is a normalized integer or whatever. The floating-point bit-level representation is preserved. to_i end end If you are sure the numerals have at most two digits and are of moderate magnitude' reading them as double, multiplying by 100, and rounding to the nearest integer will produce the correct result. 6) should equal 4 instead of 3. This includes the possibility that round(x) returns the same value as roundEven (x) for all values of x. For example: highp int can be converted to highp float, mediump int can be converted to mediump float; But a lowp int void cannot be converted to a lowp float. 23455)) Otherwise you can use modf to split a floating number into a tuple I have a newbie question about floating point numbers in PostgreSQL 9. I’m using a GL_RGBA_FLOAT32_ATI texture (accessed in a vertex shader), out of which the RGB part is being used, but the A part is free for other uses. After 4 rounds of interviews the salary range is lower than expected, even when I shared my current situation A vec4 is usually 128 bits (4x32-bit float), so packing it into a single float is problematic. layout(std140) uniform MyBlock { float myDataArray[size]; }; You then access that data in the shader just like an array. In order for this answer to work The OpenGL specification states precisely how conversions from int to float and from float to int should be done. Stack Overflow. 20 that are not in GLSL ES 1. There are two issues here. I guess it should work only with WebGL 2 (GLSL ES 3. f=12. There's no round() in the C++98 standard library. The floats that have exact binary representations like 1. 2f) where hsv. Is there another method I should be using? Description. b = b / 255. 97. You have to use glVertexAttribIPointer to make the data available as integer in the pipeline. g 10. From the Rust book we can learn:. 19), false is always con a highp int can be represented by a highp float. First of all, you are not correctly setting up your integer attribute pointer. 5). To create a double-precision float, use the lf or LF suffixes. 0) + 0. However, I can only use . 967 and I do . 3499998821 because 4. u is integer with binary access no pointers no casts needed. This solution is only suitable if you don't care about the difference between +0 and -0 (signed zero) for dir. So no, you should not assume that pre-4. 9, floored 12 In the post is no question and I don't see the point of converting the texCoord into integer and back to float without doing anything between. I dont have access to the floats memory so I cant read specific bits of the float. 00 floating point values are not automatically converted to integral values. Naturally, this requires that float be 32 bits in the C implementation, and that uint32_t be a supported type (but you can use another 32-bit integer type if it is not, likely unsigned int). If this number is < to 5 means no rounding Each uint16 represents a half-precision float (float16). They follow the ES GLSL spec. SELECT '25. For non-negative numbers, this is downward. The fraction 0. without having to convert the number to a numeric type To create a float literal from an integer value, use the suffix f or F as in C/C++. floor(x + 0. Now, I know I’ve got 32 bits to play with, but because GLSL doesn’t have bitwise operator support, I’m a bit stuck on how I’d I have the following frag function in my vertex shader: (the rest of the shader is the Sprite-Default shader that ships with Unity). 1. Using integers in GLSL fragment Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company You really need to use float in the first place? You have two options: 1. javascript; webgl; glsl; glsles; Share. You have no concerns here: std::round(0. Outside of the basic type of the attribute (float, integer, uint, and double), the place where the format is determined is in your glVertexAttrib*Format/Pointer call. convert float to int glsl Comment . 0 - it is about the same, that Java puts to shader. 61 will be 8 2. (int(math. I am pretty sure (but not positive) that division between integers should result in truncation (and thus flooring). #ifdef GL_FRAGMENT_PRECISION_HIGH precision highp float; #else precision mediump float; #endif precision mediump int; But the big float is so imprecise compared to the range (0-1) that the result you get is just noise. intBitsToFloat and uintBitsToFloat return the encoding passed in parameter x as a floating-point value. Divide the int by the same power of 10 but add use a float form of that (e. But when I use this, it seems I get an incorect result, becouse if I replace that expresion with an Basically, I want to use the rgb channels of a texture to store data (integers) and then use those values in my fragment shader. If you want to convert a float to an int you have to use a constructor. 0 there are built in functions for 12. Busy Bee. i = d. You can write one yourself though. hello, I have this code to convert a float to int: int(fl[1]) fl is a vec4 variable. Will C# or C++ do it? I need to decode the data in a GLSL or HLSL vertex shader. – This will not work. Consider The best you can do is probably to simply use floats that do not have a fractional part. Round(z))) // outputs "5" } math. Good: float f = 0. 0000000 whereas inside the compute shader, if i have a uint a=1; and I try to convert it into a The mod function in GLSL is always a floating-point mod. 4 + 0. 35 * 100. Am I correct the above is equivalent to: float X = float(34)/float(255); But, the cast from uint8 to float introduces error, and so does the division. Ahhh ok. Back in C/C++/etc code, you create a buffer object and fill it with floating-point data. – Nicol Bolas. Round float to 2 decimals javascript but round to down. int(round(some_float)) This converts a float to an integer fairly dependably. It simply expects to convert it to a float for consumption by GLSL. HLSL: cast bracket dereference index to int type if not. Viewed 39k times 16 . It's not storing a GLSL float in a GLSL vec4. 35 If I am understanding you correctly, your issue is in the line vec3 target2 = (alum + blum) / (2. The division causes all the colors to be 1. This includes the I am working with uint8 and uint16 textures in GLSL ES. EDIT: solved, as per the answer below. It is a list of values that influence the final fragment value, and when I think of it that way perhaps a 1d-texture is the natural way to go. Converting one to a float isn't on that list. Python integers are arbitrary precision, so even very large In the general case, there is not a 1:1 mapping between a vertex and a fragment. So a general answer really isn't possible. I found some PD Java code that looks like it will do the job, but I am struggling with porting the last statement, which uses a couple of zero-extend right shifts (I think the other shifts are fine i. The range of values that can be represented exactly will be more limited than an integer using the same storage space. By default, the associated data per vertex is interpolated across the primitive to generate the corresponding associated data per fragment, which is what smooth shading does. ) around the float? The bigger question, is why you need an integer in the first place? In my not-so-inconsiderable library of shader code, I recall only one use of a non-constant integer. Description. I have a float, which I want to round to the hundredth of a decimal. What may be the problem? I suspect it relates to precision, but do not undertand how to fix it. How can I have the value round up in javascript? Hot Network Questions I'm using C (not C++). ghost mentioned this issue Apr 7, 2017. – Rabbid76. I'm trying to interpolate coordinates in my fragment shader. i; /* multiply Quote: Original post by JohnnyCodeI need an integer becouse I use it as an index in an array, and since it is retrieved from a attribute variable it is a float, for attribute variablers can be &#111;nly floats, is it so?I don't see why that would be the case - int(x) Conversion to integer will truncate (towards 0. 0 in the case of bytes, as in david van brink's answer. Note that C++11 includes std::round, std::lround, and std::llround as builtins already. 4 is that “f’ 0 is then cast to an unsigned binary integer value with exactly b bits”. 5 (Chapter 5. Returns an unsigned integer obtained by converting the components of a two-component floating-point vector to the 16-bit floating-point representation found in the OpenGL Specification, and then packing these Any time you're trying to convert floats/doubles to ints, you want to think carefully about which operator you want to use -- truncating (rounding down), rounding up, or rounding-to-nearest. 5 Shaders casting uint8 to float, and reinterpretting it back to uint. 8. 8 specification, section 8. 35 isn't exactly representable in a float. Yes. 7. " – Quote: Original post by swiftcoder Quote: Original post by JohnnyCode is there some other way of how to convert a float to int then wrapig int(. Round(precise, 0) yields a floating-point value which is smaller than the actual value by any non-zero amount, (int)Math. In C you can use the following well vectorizable function. eg: 8. Quote: Original post by swiftcoder Quote: Original post by JohnnyCode is there some other way of how to convert a float to int then wrapig int(. Source: gamedev. Share. In a GLSL fragment shader I am trying to cast a float into an int. There is no math. ; Conversion from a floating-point type to an integer type by the GPU HI Iam running into some problems doing type conversion in a compute shader 4. 0, and true is converted to 1 or 1. You can either use a 16 bits int texture instead or you can divide the texture sample with an integer division before converting it to float (and then divide by a smaller float). without having to convert the number to a numeric type I keep sprite's color as unsigned int and have to convert it to 4 floats to pass them to the shader. it very clear its not allowed. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Start with a number whose mantissa is your number (00000011 in your example) and whose exponent is 01111111 (127, which is how 0 is stored in excess-of-127) Count how many bits are from the LSb to the last set bit (not included). It doesnt seem to convert the variable. Since this is an issue with floating-point representations, this is true not just in F#, but C# and (IIRC) Java and other languages. In ES 3. I did think maybe the first one When casting float to int the decimal is discarded. r = curPosition. There are lots of answers that explain this behavior. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Dollars to donuts you get something approximately like 4. Isn't there a risk of floating-point inaccuracies causing trouble here? If Math. See section 2. Improve this answer. 5 implementations always round down. Also I tried making an array of floats and using the int as an index but that didn't work either! ( I Unfortunately, it doesn't do rounding. decode rgb value to single float without bit-shift in glsl. Using the flat keyword, no interpolation is done, so every fragment generated during the rasterization of that In C you can use the following well vectorizable function. * clum);. 0,0. Maybe you can use the same idea in hlsl. 3 Common Functions. Is there any way I can get GLSL to treat the float as an int? In GLSL ES 1. // Converts the interger id to [0 - 1] range and I know there is no round in glsl with a given number and if statements are time intensive. I have a newbie question about floating point numbers in PostgreSQL 9. The second way is ceil round() has non-standard rounding semantics: halfway cases round away from zero. Tags: glsl int whatever. If you did what you suggest, just writing the floating-point value to the red channel of the framebuffer, you'd only get 8 bits of I was reading this article on conditional elimination, but it is using code techniques that GLSL doesn't have (direct access to bits). How to correctly round decimals in a number (basics): We start from far right number: If this number is >= to 5 rounding is required, we will then report a 1 to the first number on the left. I need to interpret its bytes as an int. 967 is over 900mb of space that wont be accounted for in the displays. Println(int(math. I want to calculate a normal on the CPU, and somehow pack it into that single float (A). Round(y))) // outputs "6" fmt. round returns a value equal to the nearest integer to x. S. How can I do this? P. (D3D's FLOAT-to-UNORM is basically the same, except adding 0. If you pass ints, it is very likely that a costly conversion will take place. Related. Have wanted this before and now I want it again. Commented Feb 19, 2016 at 1:27. Item Description; x [in] The specified value. I'm having problems rounding. The compiler raises an error: I tried raising the precision of the int: but to no avail. Matt. round # => 2. 4 guarantees you nothing about how the conversion is done. I've started testing stuff with "shadertoy" and the How to avoid int->float conversion when passing data to pixel shader? GLSL Error: "Type should be float or int" 0 GLSL converting uint to float for color. When the compiler casts a float to an int it truncates. i ^ d. glVertexAttribPointer with GL_FLOAT: integer values 1 (the correct result) this works because OpenGL 1) thinks the source data is in floating point form and 2) thinks the shader inputs are also in floating point form (they are actually int and int), so therefore does not apply any conversion, leaving int as int (or float as float, as it thinks). 9999999999, you will not get what you expect. The exponent is always base-10. Since Go is a bit clever with extending, the solution to the port is eluding me. As for why you can't do this, it's because Vulkan compilers should be as simple as possible. If your number can be negative, this will round the magnitude downward, unlike math. r = r / 255. If the encoding of a floating point infinity is passed in parameter x, the resulting floating-point value is the corresponding (positive or negative) floating point infinity. 0); ? And what’s this thing about GLSL be When trying to compare the numbers against the user input always comes up as false comparing a float (from sheet) to int (from user). 0 Answers Avg Quality 2/10 Closely Related Answers Having managed data as int[] where it's tightly packed array of only colors (where int format is: RGBA meaning 0xAABBGGRR), then defining vertex attribute as: GL. This function is supported in the I have a float4 coming into a compute shader, 3 of these floats are really floats but the fourth is 2 uints shifted together, how would i convert the float to uint by preserving the bit sequence instead of the numeric value? Description. My question is what is the result of that operation? opengl; vector; glsl; scalar; Share. By default, all floating-point literals are of type float. Commented Jul 12, 2022 at 16:02. non-negative). GLSL uses the IEEE 754 floating-point definition for float:. 0 or greater rendering the image as white. Provides GLSL functions to pack and unpack half, single and double-precision floating point values into more compact integer types. What you're trying to do is pass an integer as an integer, not to int-to-float conversion. It seems that implicit conversion doesn't happen in GLSL. opengl-es; opengl-es-2. 12. In cases where an operation is not defined in linear algebra, the operation is typically done component-wise, where the The same issue as every other answer in this thread Math. GLSL 3. @Hofstad is correct with the math. This happens above approximately fVertexInteger >= x. x := int(3. floor(Number x) suggestion to eliminate the bits right of the decimal, you might want to round instead. texcoord); int r = int(c. 1, but apparently since that time *the world half has been reclaimed by the modern GLSL spec at some point. What it's doing is storing a value in a vec4 which, when written to an RGBA8 framebuffer (32-bit value) can be read as a vec4 and then reconstituted into the same float that was given previously. Can it be optimized? I mean can I pass not floats, but unsigned chars as components to the shader and avoid "divide by 255" operations? What should I change in shader and in C++ code to do it? opengl; pixel-shader; Share. 5 will round in a direction chosen by the implementation, usually in the direction that is fastest. 10. If an inf or NaN is passed in, it will not signal, and the resulting floating point value is unspecified. In my test I'm not using textures, I just convert the texture index to a color (0: red, 1: blue, 2: green). latter I would like to pack all the info into a single integer and casting that int to a float is pivotal to reducing the amount of vram i use <- I'm making a voxel game engine. The algorithm in question seems bogus; it doesn't take into account the fact that opengl divides by 255 and truncates. Follow edited Jun 21, 2014 at 15:32. 14f; int myInteger = (int)myFloat; The output of this code will be 3, even if the myFloat value is closer to 4. Find out how to use swizzling, arrays, structs, and interface blocks to manipulate data. Return Value. Add a comment | 1 . floor — find the nearest integer less than or equal to the parameter @Mark: The function accepts an int just fine. 0 and so i == 1 is guaranteed The standard insists on the closest integral value assumable by a double being returned. 3 Common Current WGSL SPEC only defines the type conversion froms int/uint/float to bool but misses the type conversions from bool to int/uint/float. I have encountered severe performance differences between using const and non-const arrays (depending on their GLSL doesn't deal in sized types (well, not sized types smaller than 32-bits). Example: This is the modern c++ approach using a template function which is working for float, double, long, int and short (but not for long long, and long double because of the used double values). Declaring a constant value allows the GLSL compiler to perform optimizations that wouldn't be possible otherwise. But just to be safe, I decided to go with a type-casting solution. 25 round to have an even least significant digit, but the others appear to round randomly. If the encoding of a NaN is passed in x, it will not signal and the resulting value will be undefined. Issue is texture Learn about the basic and opaque types in GLSL, the OpenGL Shading Language. floor and round. Item Return Value. But there you go! You can try it on JSperf to see the slight speed up you get! Hope that helps! In GLSL ES 2. So floor( int(2) / int(3) ) is invalid. Name Template Type Component Type Size; x: scalar, vector, or matrix: float: any: ret: same as input x: float: same dimension(s) as input x: Minimum Shader Model. If an inf or NaN is passed in, it will not This will not work. What's a clean way to cast so that it rounds to the nearest whole number instead. I would probably do a single read from this array per fragment. Follow edited EDIT: padding it out with float[2] to force the int member onto the next 16-byte boundary did not work either. g * 255); int b = int(c. For example a 16-bit float (half float) has 11 bits of precision, and can exactly represent integers from 0 to 2048. Thanks for pointing it out. Share . UnsignedByte, true, sizeof(int), IntPtr. The ES spec makes. You would be better suited casting the columns that were text, to numeric, to integer, so that rounding is taken into consideration e. . It's enough if you call glGetUniformLocation() once and cache the result. x; raises warning C7011: implicit cast from "int" to "float" but curPosition is defined as vec3 (so it is a float) and The spec shows all possible implicit conversions inside a table, also int-> float. Javascript - Rounding a number. x;is called? Let’s say uint8 34 is stored at Quote: Original post by JohnnyCodeI need an integer becouse I use it as an index in an array, and since it is retrieved from a attribute variable it is a float, for attribute variablers @jaz I never tried that in GLSL but for float binary access in C++ I am using union { float f; DWORD u; } y; y. (Or with SSE1 for converting to an int or long at the same time). However, the resulting float value might be a Nan of some type, in which case converting it back to an int when I make it into a float it does work and everything is fine. Contributed on Jan 06 2022 . e. Im stuck in GLSL 130. float a = 1; My problem is, GLSL doesn't have a "%" operator or any bitwise operator! TLDR: How do I convert a 32bit number to 4 8bit numbers by using the operators in glsl. So, here is my solution. Therefore almost all of its operators are overloaded to perform standard vector and matrix operations as defined in linear algebra. 5 before truncation, but it's still lossy. g. stackexchange. It only has signed/unsigned integers, floats, doubles, booleans, and vectors/matrices of them. int nRefinementIterations = 100. 3,120 4 4 gold badges 31 31 silver badges 36 36 bronze badges. For example, 1 could be 0. To acces the single bytes, you can use the standard integer bit shift operations in GLSL, like you could do in C. There was a bug with the packing of the exponent, which i changed so the exp takes one 8bit float and the sign is packed with the mantissa: Editor's Note: The following answer provides a simplistic solution that contains several implementation flaws (see Shafik Yaghmour's answer for a full explanation). 3) # 1 round(Int, 1. I guess if I rewrite % with mod, this code works well. (rint is similar, but it's required to raise the FP "inexact" exception when the result Ive gota float my_float; in my shader. float4 SpriteFrag(v2f IN) : SV_Target { float4 c = tex2D (_MainTex, IN. 0. 0; glsl; Share. 0 is a floating point value, but the data type of nRefinementIterations is int. Skip to main content. 5, "Fixed-Point Data Conversions": Conversion from integer type to float should be done by dividing by 2^b-1, i. Are you checking for warnings and errors when you compile? I don't really get what the rest of your problem is so this may or may not be your Otherwise, multiply by 100 or 1000, round and then divide again. answered Feb 6 If you want to convert Float to Int, this is a two-step operation. The root of the logic though is using the integers 1 and 0 to calculate a value rather than going through if-then statements. Improve this question. you can increase the value clum is multiplied by to get an image to show up it's not a conjecture. 2. So long as you don't overflow the receiving type. I want to mix different types in one, ala interleaved VBOs. But if you normalize the float in the [0,1] range, you'll have precision problems! Note that you can't store alpha too(in this way), since highp floats are 24-bit long, and not 32 as the ones normally The following line in my fragment-shader gl_FragColor. 0) so integer gets converted to float and the new value is the correct value. 5f);. Follow edited Apr 20, 2022 at 6:12. Thanks. b * 255); c. But the 32-bit “single precision” floating point format uses some of its bits to represent the exponent and the sign: Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog redorav changed the title HLSL - No implicit cast from float to int when accessing arrays HLSL - No implicit cast from float to int (e. 5; int I = (int)f; The latter isn't legal syntax. to_i it will chop it down to 49 which for my use of disk space analysis . 0 as 1. Name. 1. Type Description. The fraction 0. round gives rounding errors with floats. 00) – Entity Black. The second way to first round the NormValue then use casting. Is there an operator that will allow me to turn the float directly to integer with all the same bits instead of an ordinary cast You could implement getNthBit(float v, int bit) as. But, this is for the variables which I can find the range. 345; var b = ~~a; //boom! We can use Math. round(Int, 1. 60 Specification - 5. e. Add a comment | round won't change that and the return type of round is a floating point type too. Respectively, the floor and ceiling functions generally map a real number to the largest previous or smallest following integer which has zero decimal places — so to use them for 2 decimal places the number is first As @plowman said in the comments, Python's round() doesn't work as one would normally expect, and that's because the way the number is stored as a variable is usually not the way you see it on screen. In your example: there are only one bit from the LSb to the last (most significant) bit set, so the int(x) Conversion to integer will truncate (towards 0. The latter set do not round consistently, probably due to inexact binary representations of some of the values. (Simply casting a double to an integer truncates, not rounds to nearest, and will sometimes produce incorrect results due to floating-point rounding errors. How do I cast the int properly? There are several possible solutions to this, probably the easiest is just use an int directly. 0f; c. rgb *= c. 52. floatBitsToInt and floatBitsToUint return the encoding of their floating-point parameters as int or uint, respectively. 1k 12 12 gold I need to pack an int into a float and then convert it back into an int again. 5); (The trickyness with floor is because C++ doesn't have a native round() function) I am using webgl2. You have to initialize nRefinementIterations by an integral value:. 999999996. Round() does return a float64 value but with int() applied afterwards, I couldn't find any mismatches so far. According to the Vulkan GLSL specification, only certain operators can be used on a specialization constant in order for it to remain a specialization constant. 0; Floats can also be defined using exponential notation, using the e or E to separate the base from the exponent. a; return c; } and the following color If i have a float of 49. 3. floor which rounds towards -Infinity, making a lower value. g = g / 255. 1 OpenGL integer texture raising GL_INVALID_VALUE Returns a floating-point value corresponding to a signed integer encoding of a floating-point value. 0. 0, but without any effect. Tried to replace d with float value of 100. intBitsToFloat and uintBitsToFloat return the encoding passed in parameter x as a highp floating-point value. And that accepts 16-bit floats. What you need to do is get those two ranges closer. i & 0x80000000; /* extract the sign bit */ x. zfmktf auebm vfpeqa smyuwmz xyohez khecq bpujli zhnal vwker ixhlq