On Tuesday, 2 June 2015 at 17:03:32 UTC, Alex Parrill wrote:
> On Tuesday, 2 June 2015 at 16:41:38 UTC, Kyoji Klyden wrote:
>
>> src:
>>
>>        string source = readText("test.glvert");
>> 	
>> 	const string sources = source.toStringz;
>> 	const int len = source.length;
>> 	
>> 	GLuint vertShader = glCreateShader( GL_VERTEX_SHADER );
>> 	
>> 	glShaderSource(vertShader, 1, &sources, &len);
>>
>> pt.d(26): Error: cannot implicitly convert expression (toStringz(source)) of type immutable(char)* to const(string)
>>
>> pt.d(34): Error: function pointer glShaderSource (uint, int, const(char*)*, const(int)*) is not callable using argument types (uint, int, const(string)*, const(int)*)
>>
>> -
>>
>> I also tried passing the char array instead but no go.. What am I missing? :\
>
> Oops, do `const immutable(char)* sources = source.toStringz` (or just use `auto sources = ...`).

OMG IT FINALLY WORKS :O
(%1 of the program complete!)

Thankyou very much, this was a huge help! It's such a small piece but I feel like a learned alot from this. :)

On Tuesday, 2 June 2015 at 16:41:38 UTC, Kyoji Klyden wrote:
> src:
>
>         string source = readText("test.glvert");
> 	
> 	const string sources = source.toStringz;
> 	const int len = source.length;
> 	
> 	GLuint vertShader = glCreateShader( GL_VERTEX_SHADER );
> 	
> 	glShaderSource(vertShader, 1, &sources, &len);

Judging by the docs, you don't need null-terminated strings and can use native D strings, just pass their lengths:

	string source = readText("test.glvert");

	const char* sources = source.ptr;
	const GLint len = cast(GLint)source.length;

	GLuint vertShader = glCreateShader( GL_VERTEX_SHADER );

	glShaderSource(vertShader, 1, &sources, &len);

On Wednesday, 3 June 2015 at 08:11:16 UTC, Kagamin wrote:
> On Tuesday, 2 June 2015 at 16:41:38 UTC, Kyoji Klyden wrote:
>> src:
>>
>>        string source = readText("test.glvert");
>> 	
>> 	const string sources = source.toStringz;
>> 	const int len = source.length;
>> 	
>> 	GLuint vertShader = glCreateShader( GL_VERTEX_SHADER );
>> 	
>> 	glShaderSource(vertShader, 1, &sources, &len);
>
> Judging by the docs, you don't need null-terminated strings and can use native D strings, just pass their lengths:
>
> 	string source = readText("test.glvert");
>
> 	const char* sources = source.ptr;
> 	const GLint len = cast(GLint)source.length;
>
> 	GLuint vertShader = glCreateShader( GL_VERTEX_SHADER );
>
> 	glShaderSource(vertShader, 1, &sources, &len);

Oh that also works quite well!
Is casting necessary there though? DerelictGL treats GL types as D types, and .length is size_t so wouldn't it just turn into an int regardless??

Also the one part I don't understand is with &sources. So is this passing sources as a reference, but sources itself is a pointer to a pointer? I'm just a tad confused on how this part works :S

On Wednesday, 3 June 2015 at 10:21:20 UTC, Kyoji Klyden wrote:
> On Wednesday, 3 June 2015 at 08:11:16 UTC, Kagamin wrote:
>> On Tuesday, 2 June 2015 at 16:41:38 UTC, Kyoji Klyden wrote:
>>> src:
>>>
>>>       string source = readText("test.glvert");
>>> 	
>>> 	const string sources = source.toStringz;
>>> 	const int len = source.length;
>>> 	
>>> 	GLuint vertShader = glCreateShader( GL_VERTEX_SHADER );
>>> 	
>>> 	glShaderSource(vertShader, 1, &sources, &len);
>>
>> Judging by the docs, you don't need null-terminated strings and can use native D strings, just pass their lengths:
>>
>> 	string source = readText("test.glvert");
>>
>> 	const char* sources = source.ptr;
>> 	const GLint len = cast(GLint)source.length;
>>
>> 	GLuint vertShader = glCreateShader( GL_VERTEX_SHADER );
>>
>> 	glShaderSource(vertShader, 1, &sources, &len);
>
> Oh that also works quite well!
> Is casting necessary there though? DerelictGL treats GL types as D types, and .length is size_t so wouldn't it just turn into an int regardless??

size_t can be 32bit or 64bit, depending on your platform. Don't know how large GLint is. Assigning 64bit to 32bit requires an explicit cast, because it can lose information.

>
> Also the one part I don't understand is with &sources. So is this passing sources as a reference, but sources itself is a pointer to a pointer? I'm just a tad confused on how this part works :S

A string (or any other array slice for that matter) is internally the equivalent of:

    struct Slice(T) {
        T* ptr;
        size_t length;
    }

(maybe the order of fields is different, I never remember that part)

`&source` will give you the address of that structure.

On Wednesday, 3 June 2015 at 10:28:50 UTC, Marc Schütz wrote:
>
> A string (or any other array slice for that matter) is internally the equivalent of:
>
>     struct Slice(T) {
>         T* ptr;
>         size_t length;
>     }
>
> (maybe the order of fields is different, I never remember that part)
>
> `&source` will give you the address of that structure.

hmm I still a bit confused..

So in "const char* sources = source.ptr;" sources is just turning the property ptr of source into a variable, and then in glShaderSource you're passing the memory address of sources (which is technically source.ptr) to the function?

Do I have that right? If I do, then I think this all makes sense

On Wednesday, 3 June 2015 at 10:21:20 UTC, Kyoji Klyden wrote:
> On Wednesday, 3 June 2015 at 08:11:16 UTC, Kagamin wrote:
>> On Tuesday, 2 June 2015 at 16:41:38 UTC, Kyoji Klyden wrote:
[...]
>> 	string source = readText("test.glvert");
>>
>> 	const char* sources = source.ptr;
[...]
>> 	glShaderSource(vertShader, 1, &sources, &len);
[...]
> Also the one part I don't understand is with &sources. So is this passing sources as a reference, but sources itself is a pointer to a pointer? I'm just a tad confused on how this part works :S

`&sources` is a pointer to `sources`. `sources` itself is a pointer to a char (leaving const-ness aside). So `&sources` is a pointer to a pointer to a char.

On Wednesday, 3 June 2015 at 10:56:21 UTC, Kyoji Klyden wrote:
> So in "const char* sources = source.ptr;" sources is just turning the property ptr of source into a variable,

yes

> and then in glShaderSource you're passing the memory address of sources

yes

> (which is technically source.ptr)

No, the address of sources is not the same as `source.ptr`.

> to the function?
>
> Do I have that right? If I do, then I think this all makes sense

Ooooh okay, I'm starting to get it. I think this last question should clear it up for me: When a string is made, how is the struct Slice handled? What does ptr get assigned?

On Wednesday, 3 June 2015 at 11:23:09 UTC, Kyoji Klyden wrote:
> Ooooh okay, I'm starting to get it. I think this last question should clear it up for me: When a string is made, how is the struct Slice handled? What does ptr get assigned?

ptr is a pointer to the first char, in other words the address of the first char.

On Wednesday, 3 June 2015 at 11:28:14 UTC, anonymous wrote:
> On Wednesday, 3 June 2015 at 11:23:09 UTC, Kyoji Klyden wrote:
>> Ooooh okay, I'm starting to get it. I think this last question should clear it up for me: When a string is made, how is the struct Slice handled? What does ptr get assigned?
>
> ptr is a pointer to the first char, in other words the address of the first char.

I think I get how it's all basically working now. I've realized that my confusing is all coming from not understanding how D handles arrays, so I'm going to go look into that for a while.

Thanks for the help!