[fpc-pascal] Next language feature for pas2js...

[Michael Van Canneyt]

On Tue, 1 May 2018, Ryan Joseph wrote:

>
>
>> On May 1, 2018, at 4:10 PM, Mattias Gaertner <nc-gaertnma at netcologne.de> wrote:
>> 
>> In pas2js it will probably look similar to this:
>> 
>> var vertices: array of glfloat = (-0.5, 0.5, -0.5, -0.5, 0.0, -0.5);
>> var vertex_buffer: TInsertNameHere;
>> begin
>>  // Create a new buffer object
>>  vertex_buffer = gl.createBuffer();
>>
>>  // Bind an empty array buffer to it
>>  gl.bindBuffer(gl.ARRAY_BUFFER, vertex_buffer);
>>
>>  // Pass the vertices data to the buffer
>>  gl.bufferData(gl.ARRAY_BUFFER, Float32Array.new(vertices), gl.STATIC_DRAW);
>>
>>  // Unbind the buffer
>>  gl.bindBuffer(gl.ARRAY_BUFFER, nil);
>> end;
>> 
>
> Strange they renamed glGenBuffers to createBuffer().
>
> That aside though not having records is a problem I imagine. They don’t exist in JS right, so how do they deal with that? I guess you could pack a record into an array literal if all the types were the same. Arrays of arrays in literals works also.
>
> can’t we do that? We’re at the mercy of Float32Array.new packing that though or we need another method. What a waste of processing to convert that. That would be a nightmare for real applications to iterate all the verticies like that every time they were copied to the GPU.

What's wrong with the above code ?

It obviously works well enough, otherwise they wouldn't have made the API so.

The float32 array is a Javascript type that encapsulates a memory buffer.
I assume the webgl creators decided it has the optimal layout for their
needs.

Michael.