Re: Trouble with tables

[Kerp]

stefan your right that was it, thank you. I'm pretty sure i got it fixed with 
this code. I realized i needed a continue in the if statements too.


proc sort_queue_properties(index:int): TableRef[uint32,string] =
  result = newTable[uint32,string](queue_properties[index].queueCount.int)
  for i in 0 .. 

Re: Trouble with tables

[Kerp]

still having problems, it seems that the table loses its info on length and 
value when i return it?

for instance


proc sort_queue_properties(index:int): TableRef[uint32,string] =
  var queue_table = 
newTable[uint32,string](queue_properties[index].queueCount.int)
  for i in 0 .. 

Re: Trouble with tables

[Kerp]

Interesting enough


var queue_table = Table[uint32,string]()


actually compiles on my machine.

i'm using mingw64-6.3 from this website and x64 nim_0.17.0 too it maybe why i 
am confused.

i haven't used tables before, i don't know what the correct syntax is.

Trouble with tables

[Kerp]

Hello again

having trouble with any of the tables, i'm not sure how they work it seems, and 
the manual is kinda skimpy too.

so here is my code


proc sort_queue_properties(index:int): Table[uint32,string] =
  var queue_table = Table[uint32,string]()
  for i in 0 .. 

Re: Gource visualization of the Nim repo history

[Kerp]

Thats kinda weird looks like a flower in the end!

Re: GetWindowEx() in winlean?

[Kerp]

hey thanks dom i will see what i can do.

GetWindowEx() in winlean?

[Kerp]

just wondering where it is? I could not find it in "winlean" import.

But i need it to create a window in vulkan cause i don't want to use glfw.

or if its possible do i just make a binding for it?

Re: Nim on Android

[Kerp]

awesome!

casting address of pointer functions to a type

[Kerp]

Hi again just need to know what i'm doing wrong on this subject

But first here is my code


var vkCreateDebugReportCallbackEXT = 
cast[PFN_vkCreateDebugReportCallbackEXT](vkGetInstanceProcAddr(inst,"vkCreateDebugReportCallbackExt"))



i get a message from the compiler about this when i try it, that it cannot 
convert to a pointer type. i believe its because its pointer function in c and 
maybe nim does not like casting those, i dunno?

vcc and nim vs mingw with vulkan

[Kerp]

hello just wondering what the plans are or potential roadblocks to getting nim 
to be used by vcc on windows. I don't see any docs on this but there is 
obviously the mingw-64 download on the site.

The reason i'm asking is after getting to to "vkCreateCmdPool" in the vulkan 
api seemingly cannot go further because it seg-faults in nim.

I think it is a problem with the compiler(mingw) not working with the vcc build 
lib in the sdk. I can't prove that yet so no accusations here. But there are 
posts on stackoverflow about this.

Anybody got any ideas to make it work better? if not i will wait till nim 
switches to vcc to work on vulkan. But i do have some c++ code working with 
vulkan right now, it seems there are slight incompatabilities with mingw and 
vcc so i have to pick one.

Re: Using cstringArray and allocCstringArray

[Kerp]

Thanks mashagingan that did the trick

Re: Using cstringArray and allocCstringArray

[Kerp]

hmm, still having some trouble, it seems nim won't let you politely cast 
cstring to string. I tried unsafe cast and it compiles but i get the "out of 
memory" err.

But i have to use cstringArray for the vulkan lib in the end.

I will come back later and do some digging in the docs. and maybe somebody will 
suggest something.

Re: Using cstringArray and allocCstringArray

[Kerp]

And while i'm at it, anyone know how to either use the __LINE__ macro from the 
compiler in nim? Or even the '#' stringify preprocessor symbol?

I have a template that checks the proc result calls in vulkan and puts out the 
error string. Nim makes it easy to do this, but i dunno what the corresponding 
line is where the error or proc call is.

Re: Using cstringArray and allocCstringArray

[Kerp]

Hi stefan it seems your suggestion jogged my memory banks a bit.

Here is what i came up with. It seems to work so far.


var s : seq[string] = newSeq[string](extension_count)
  for i in 0 .. s.len:
var f = extension_prop[i].extensionName.cstring
s[i] = newString(256)
s[i] = cast[string](f)
  
  extension = alloccstringArray(s)


and thank you for your help

Using cstringArray and allocCstringArray

[Kerp]

Hello, having trouble using allocCstringArray to to allocate enough space for 
my extensions in Vulkan.

The problem is that the extension member is an array of 256 char so i cannot 
use it in allocCstringArray.

So here is the code to my problem.


VkExtensionProperties* = object
extensionName*: array[vkMaxExtensionNameSize, char]
specVersion*: uint32


i can get the "extensionName" member to a cstring but allocCstringArray wants a 
openarray of string.

so this is far as i got tonight.


for i in 0 .. extension_prop.len:
  var s = (extension_prop[i].extensionName.cstring)
  extension = allocCStringArray(??) #what to do here?


and i have to use cstringArray for the "extension" type. I'm sure there is 
someway to do this. 

Re: int literals and if statement

[Kerp]

hi stefan , i'm using this binding.

[vulkan binding 
https://github.com/nimious/vulkan](https://forum.nim-lang.org/postActivity.xml#vulkan-binding-https-github-com-nimious-vulkan)

if there are ways to improve it i will ask, but for now it seems to be ok.

Re: int literals and if statement

[Kerp]

yes Araq thank you, it has worked i believe after investigating it. it seems my 
hardware has a "vkQueueGraphicsBit" on every queue since its nvidia. 

int literals and if statement

[Kerp]

Hello i'm having trouble knowing what to do in this case. It seems the int 
literal in the vulkan binding code does not work with an if statement since it 
is an int literal.

so the offending code.


proc create_device(self:Render) =
  for index in 0 .. 0:
for i in 0 .. queue_prop[index].queueCount:
 if queue_prop[index].queueFlags and vkQueueGraphicsBit == 1: # 
vkQueueGraphicsBit
   echo "index found on: ", queue_index
   break

queue_index.inc
  
  err_check(vkCreateDevice(gpu_list[0],addr device_create_info, nil, addr 
device))


the line here... wont evaluate to a bool


if queue_prop[index].queueFlags and vkQueueGraphicsBit == 1: # 
vkQueueGraphicsBit


queueFlags is of queue_prop, and is the type "VkQueueFlags". as is the int 
literal "vkQueueGraphicsBit", which is 0x0001 int literal in the binding.

So i'm thinking that i need to do operator overloading but, i must admit i 
don't know how in this case. Any ideas appreciated. and i will keep searching 
the documentation.

edit:

trying this but it always resolves true and i don't believe it should.


if (queue_prop[index].queueFlags and vkQueueGraphicsBit).bool == 1.bool:

Re: Anyone tried the "nim secret"?

[Kerp]

Yes i i have used it it is useful!

Re: Installation on 64-bit Windows

[Kerp]

It seems too that tdm-gcc is the most convienent way in windows to get a 
compiler but it does not seem to like vulkan libs (trouble linking). And you 
have to deal with winpthreads licence, but you get a working compiler easier it 
still works for opengl for instance. but i switched too linux mint to play with 
vulkan and nim.

Anything wrong with this syntax?

[Kerp]

just realized this is not how the documentation uses properties but i'm 
wondering if using them as a constructor type thing is a problem in nim. So far 
it seems fine but its not in the manual.

so here's my example...


var cmd_pool: VkCommandPool

type
  CommandBufferPool* = ref object
   cmd_pool_info : VkCommandPoolCreateInfo
   que_type_flags*: seq[VkQueueFlags]
   phys_device*: VKDevice
   result*: VkResult

proc `=CommandBufferPool`*(self:CommandBufferPool) =
self.cmd_pool_info.sType = VkStructureType.commandPoolCreateInfo
self.cmd_pool_info.pNext = nil
###
for i in 0 .. *(self:CommandBufferPool) =



And then the <> brackets would insert a = sign to make it a constructor?

Re: pointer arithmetic example?

[Kerp]

this what i came up with for the + operator


proc `+`(a:pointer,p:pointer): pointer =
  result = cast[pointer](cast[int](a) + 1 * sizeof(p))


I believe a person has to times the sizeof p by 1. But i could make it use 
generics too i guess but i dunno.

And thank you filwit for your post it was perfect.

i will look into create and resize the unchecked pragma.

pointer arithmetic example?

[Kerp]

I am still relatively new to doing this even in c, because i was used to using 
vector in c++.

But since i am learning nim i don't know the way to correctly put a pointer 
into a pre allocated pointer using cast in nim.

So here is what i'm working on.


import ../obj_parser, streams


type
  BinWriter* = ref object of RootObj
   obj: ref obj_data

proc readObjFile*(self:BinWriter,name:string) =
  self.obj = getObjFile(name)

proc createBinary*(self:BinWriter,filename:string) =
   var s = newFileStream(filename,fmwrite);
   if s != nil:
var total : int = 0

total += (self.obj.vert.len * sizeof(float32))
total += (self.obj.face.len * sizeof(uint32))
total += (self.obj.nrml.len * sizeof(float32))
total += (self.obj.tex.len * sizeof(float32))

var all : pointer = nil
var vert = alloc(self.obj.vert.len * sizeof(float32))
for i in 0 .. 

Re: Version 0.15 released!

[Kerp]

Very awesome! I will enjoy my continued learning of nimrod

lulzz..

[Kerp]

[Britney spears created 
this!!](http://forum.nim-lang.org///nim-lang.org/docs/idetools.html)

i did'nt know. too funny..

Re: Nim Documentation - a GitBook version

[Kerp]

Being a someone who is kinda new to the terminology of computer science i find 
that in nim the documentation may be perfect for seasoned people who have a 
clue, but i did not at first. Till i started searching individual topics like, 
hygenic macros and such.

So my suggestion to add to this is that while maybe, documentation that 
approaches the novice or noob have an appendix of the explanations of the 
terminology that is used in the documentation on this website. I wish i would 
have had it, and maybe i still need it? i dunno, i like all the ideas here and 
would like to help but i am not self confident enough to volunteer yet.

i like jlp765's idea of a periodic "lets figure this out together moment". 
maybe based on problems people from other languages who do not know nim so well 
like me, need to know.

For instance maybe pointer arithmetic... its different in c than in nim to do 
it. i think without someone like Araq showing how to do it would be a challenge 
to say the least, for me at least i know!

But in the same though maybe a category like "coming from c to nim" or "from 
python to nim" would be good. i think some stuff is like that on github already.

how to use Natural type?

[Kerp]

I checked the documentation, i understand i think, that a natural is a range of 
a type specifically int in the example. But other than that i have no idea how 
to use it. I'm trying to use readbytes proc in system module but having a 
little difficulty understanding what i need to do to use the proc.

But my case use is i'm trying too use my .obj parser to write the data from 
text file to a binary file then read it back from binary file, then later i'll 
make a text based scene format file.

any help appreciated. 

Opengl vertices

[Kerp]

First let me say if this is not a bug my apologies. But i think in my noobish 
experience it is.

I think i traced my problem to it in nim.

The strange behavior i get with my opengl vertices and i'm fairly certain after 
trying the same sorta thing in c++ and nim is that a vertice of 0,0,0 for x,y,z 
coords appear in the shader data when sending the vertices to the shader.

i'm certain its the first vertices of x,y,z coordinate to sent to the shader so 
maybe in nim my vector3 object is being initialized with 0,0,0? Here is my 
Vector3 object.


type
   Vec3* = object
 x*,y*,z* : GLfloat



The more i think of this the more it would to be make sense that when nim does 
a check for the variables or object maybe the first thing it does is make it 
static in c?? i don't know for sure but thats the only thing i can think of 
that would make nim do this. And i base this off some of the posts i've read 
from araq.

but if araq or someone thinks this is a bug i will post it on github.

`-` operator overloading and negative numbers of distinct type

[Kerp]

Ok here is my code i get a stack overflow on the overloaded - operator with a 
distinct type.


import math

type F_TYPE* = distinct float32 # change to suit your needs
type BASE_TYPE = distinct float

type
  Mat4_t* = array[16,F_TYPE]

type
  Mat3_t* = array[16,F_TYPE]

type
  Vec4_t* = ref object of RootObj
x*,y*,z*,w* : F_TYPE

type
  Vec3_t* = ref object of RootObj
x*,y*,z* : F_TYPE

proc `/`*(a,b:F_TYPE): F_TYPE =
  result = a / b

proc `==`(a,b:F_TYPE): bool =
  if a == b:
return true
  else:
   return false

proc `-`*(a,:F_TYPE): F_TYPE =
  return -a

proc `-`*(a,b:F_TYPE): F_TYPE =
  result = (a - b)


And here is where the compiler stops when running the program.


proc mat4_frustum(left,right,bottom,top,near,far:F_TYPE): Mat4_t =
  var dest : Mat4_t
  var
rl = (right - -left).F_TYPE #code breaks here
tb = (top - -bottom).F_TYPE #and here
fn = (far - near).F_TYPE
  dest[0] = (near.float * 2.0.float).F_TYPE / rl.F_TYPE
  dest[5] = (near.float * 2.0.float).F_TYPE / tb.F_TYPE
  dest[8] = (right + left).F_TYPE / rl.F_TYPE
  dest[9] = (top + bottom).F_TYPE / tb.F_TYPE
  dest[10] = - ((far + near).F_TYPE / fn).F_TYPE
  dest[11] = - 1.0.F_TYPE
  dest[14] = - ((far.float * near.float * 2).F_TYPE / fn.F_TYPE).F_TYPE
  dest[15] = 1.0.F_TYPE
  return dest



Specifically it breaks on the negative distinct type i think? Is this normal? I 
doubt it could be, because that would be not useful. So any ideas about how to 
get it to run correctly? or whatever else is needed...