elm-community/elm-webgl

Moved to elm-explorations/webgl

elm-webgl's Issues

Respect Evan's constraints on this package

Expressed here. Can this somehow be codified maybe?

Publish a version with deprecation notice

http://package.elm-lang.org/packages/elm-community/elm-webgl/latest is a bit misleading, because it doesn't link to the new package

Revisit open issues and pull requests from origin?

That is, go through https://github.com/johnpmayer/elm-webgl/issues and https://github.com/johnpmayer/elm-webgl/pulls and see which ones might be useful to add here?

Provide the ability to render a mesh with supplied vertices and indices.

Currently there is no way to render primitives using a supplied list of vertices and a list of indices.

Having the ability to specify the indices would save on defining duplicate vertices for the mesh definitions.

Nothing gets rendered until the program receives it's first message

As we've discussed on Slack with @w0rm , it seems that elm-webgl doesn't render anything until after the program receives it's first message. I've made a gist that exhibits this behaviour. The conditions in lines https://gist.github.com/szabba/13a90267523f122d259a16fe9c5954be#file-main-elm-L18-L23 can be used to make it work immediately or after a five second delay.

To poke at the code locally, you can clone the gist

$ git clone https://gist.github.com/13a90267523f122d259a16fe9c5954be.git

Host examples on gh-pages?

The example links on the README frontpage are dead (404). I think it would make sense to move them to GitHub (or reactivate them on elm-lang.org) or remove them.

Is is possible to add constants to the vertex array data?

I can see how you create streams of information like vertex and normal position but how do you apply constant data like using a constant vertex attribute. Maybe the intension is that you would use a uniform here?

I cant see any complex examples in this API that sheds any light on this, hence this question.

Interactivity: Picking

I would like to display additional information and change the mouse pointer type when the user hovers over rendered objects and create a new window when an entity is clicked. It would be nice, to be able to efficiently detect the rendered object that's under the user's mouse pointer.

The default way to do this seems to be picking. Examples:

• http://voxelent.com/html/beginners-guide/chapter_8/ch8_Picking.html
• https://github.com/FarhadG/webgl-picking
• http://coffeesmudge.blogspot.de/2013/08/implementing-picking-in-webgl.html

In JS this seems to be hassle-free. But I can't see how this is possible with elm-webgl. This is really sad because the modern web is defined by interactivity which includes not just rendering but also reacting on user input.

Google-ing this topic reveals that there has been a discussion about this topic which ended nowhere:
https://groups.google.com/forum/#!topic/elm-discuss/PvVxDq0K8M8

In this thread there are further references to discussions where users ask for this feature:

• https://groups.google.com/forum/#!topic/elm-discuss/7e9e6ZBGkLk/discussion
• http://stackoverflow.com/questions/24345168/how-can-i-use-a-renderbuffer-as-a-texture-in-elms-webgl-library

So there is definitely some demand.

Are there any plans to support this?

If I would try to implement this (I have no idea how hard this will be or whether it's possible at all with the current architecture), does it have any chance to be merged?

Edit: The most important missing functionality seems to be WebGLRenderingContext.readPixels()(Docs)

Edit1: Currently, I'm mostly interested in the 2D case (map overlay) where depth information is not relevant.

Examples lead to 404

The examples currently linked to from the repository README.md lead to a 404. Do these exist somewhere else now?

Extract a task to load image into separate project

A task to load image can be very helpful outside of elm-webgl. A unified Image type could be used e.g. in elm-graphics because currently its impossible to control images behaviour there, it simply triggers re-render once the image is loaded check the source.

Exploding textures cache

The textures cache seems to be increasing over time, not sure if this is the expected behaviour

Could it be a regression of #20 (cc @Ryan1729)?

Repository field in elm-package.json affects correctness of generated Javascript

I tried copying /examples/elm-package.json and /examples/first-person.elm to a new project, setting the repository in elm-package.json to

"repository": "https://github.com/genthaler/first-person-elm-start-app-simple.git",

and adding

"elm-community/elm-webgl": "2.0.0 <= v < 3.0.0"

This failed to load in Chrome, with the errors:

first-person.elm:4573 Uncaught TypeError: Cannot read property 'createNode' of undefined(anonymous function) @ first-person.elm:4573(anonymous function) @ first-person.elm:5096(anonymous function) @ first-person.elm:12681
first-person.elm:10 Uncaught TypeError: runElmProgram is not a function(anonymous function) @ first-person.elm:10

If I set the repository to

"repository": "https://github.com/aenthaler/first-person-elm-start-app-simple.git",

(i.e. genthaler -> aenthaler) then it runs.

I suspect it only works if the repository field is lexicographically earlier than "https://github.com/elm-community/elm-webgl.git".

Feel free to clone the project at https://github.com/genthaler/first-person-elm-start-app-simple

Provide the ability to load a texture without an implicit UNPACK_FLIP_Y_WEBGL

Currently the option UNPACK_FLIP_Y_WEBGL true is always implicit, it would be ice if that an other options could be applied with a version of loadtTextureWithConfig function or similar:

• gl.PACK_ALIGNMENT
  Affects packing of pixel data into memory. The initial param value is 4, but it can be set to 1,2,4, or 8.
• gl.UNPACK_ALIGNMENT
  Affects unpacking of pixel data from memory. The initial param value is 4, but can be set to 1,2,4, or 8.
• gl.UNPACK_FLIP_Y_WEBGL
  Flips the source data along its vertical axis when texImage2D or texSubImage2D are called when param is true. The initial value for param is false.
• gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL
  Multiplies the alpha channel, if it exists, into the other color channels during the data transfer when texImage2D or texSubImage2D are called when param is true. The initial value for param is false.
• gl.UNPACK_COLORSPACE_CONVERSION_WEBGL
  The browser's default colorspace conversion is applied when texImage2D or texSubImage2D are called with an HTMLImageElement texture data source. The initial value for param is BROWSER_DEFAULT_WEBGL. No colorspace conversion is applied when set to NONE.

Support the advanced mode of google closure compiler

I tried to apply google closure compiler on my webgl game, however this didn't work well and got me some JavaScript error. I believe this has to be investigated further and hopefully fixed.

Drop elm- from package name

As per elm-community/guidelines#27, and in particular this discussion: elm-community/guidelines#27 (comment).

JS Interop: Direct Access to "draw()"?

I'm currently experimenting using elm-webgl to power a canvas on a Leaflet.js map to render geo data. Basically, this is working great! I think Elm could be a good fit to render big amounts of live geo data.

Unfortunately, the JS Ports feature of Elm seems to be asynchronous which leads to a laggy view. I've created an example to show the behavior: https://github.com/felixguendling/elm-map/tree/master

The rendering works fine, but when you drag/move the map, the canvas contents get displayed at the wrong position for perhaps a few milliseconds. I assume this glitch originates from the ports not being synchronous. There are some plain JS examples that do the same with the slight difference, that the canvas update happens at the same time as the CSS update of the map.

Problem in the code (https://github.com/felixguendling/elm-map/blob/master/index.html):

app.ports.mapUpdate.send

and

var pos = this._map.containerPointToLayerPoint([0, 0]);
L.DomUtil.setPosition(this._el, pos);

are not synchronized.

So, my question is: is there a way to instantly render the changes or are there some kind of "synchronous ports" in Elm? Or is there a totally different solution to this problem?

Edit: The model needs to be updated before the synchronous redraw.

Add support to disable premultipliedAlpha

It is not possible to disable premultipliedAlpha which is very useful to have transparent sprites.

Currently the transparency issue can only be solved by hacking the shader code.

Package hardwired to elm-lang/core 4.0.0

This means the package cannot be used together with the latest, bug-fixed, release of core. Probably the bounds should be changed to "elm-lang/core": "4.0.0 <= v < 5.0.0" and a patch release of this package here be made.

Unify code formatting in the Native module

I'm not sure if there is a preferred way to format JavaScript, I am happy with any coding style but it has to be consistent.

Perhaps we can as well add an eslint config or something.

Adding Elm 0.18

Elm 0.18 is now in beta phase but this package has not been published for it.

Is anybody working on it?

Thanks.

Broken link in README

The first link in the README, with content "A simple API", is broken.

Change installation note's github links to https

Installation notes should have https links instead of the ssh ones since those are actually available for people to use in read-only capacity.