3 ms·

Thanks for the comment, I'm the developer of the app! Having it run in a browser would clearly be convenient, but unfortunately Javascript is really too slow. I

Thanks for the comment, I'm the developer of the app! Having it run in a browser would clearly be convenient, but unfortunately Javascript is really too slow. I even wish C++ was faster. Rendering the vector paths requires the same type of heavy computation as a modern AAA game, and we don't see AAA games implemented in Javascript for good reasons. The paths need to be tessellated, sent to the GPU, then the different layers need to be composited, and all of this takes computational resources. In addition, unlike Figma where the vector paths are created by manipulating control points, in VGC Illustration it is expected that the paths can be created by sketching them, hand-drawn. This requires extremely low latency and high FPS for the drawing experience to be any good. There's already quite a bit of lag between the stylus and the shown stroke even in Photoshop, you don't wan't this to be any worse :) I hope this makes sense.

Const-me 5y ago
How are you rendering these vectors on Linux? I'm asking because AFAIK unlike Windows with Direct2D, Linux doesn't have GPU-targeted vector graphics libraries. I have once made my own one when I needed something similar: https://github.com/Const-me/Vrmac#vector-graphics-engine https://github.com/Const-me/Vrmac#vector-graphics-engine
- borisdalstein 5y ago
  I'm using 3D graphics APIs, OpenGL on Linux currently, but Vulkan will be an option later. I'm converting everything to triangles on the CPU and send to OpenGL. Note that the animation app actually needs to show 3D graphics for a 2D+time visualization which is part of the innovation in my research.
  - Const-me 5y ago
    > I'm converting everything to triangles on the CPU and send to OpenGL Thanks, that’s what I thought. The library I have linked does the same thing. Only it’s either D3D12, or GLES 3.1 underneath.
    - borisdalstein 5y ago
      Wow, your library actually looks impressive! Yeah, I'm pretty much implementing all the same things.
ninetenfour 5y ago
I think you can tessellation on the CPU in an adaptive fashion (e.g. based on curvature or similar) and update that on a per frame (add, remove tessellation points) basis rather than re-tesselating from scratch each frame. The tessellation would just have weights from each control point. You can modify the vertices on the CPU, update the tessellation points and update those to the GPU. Get 60fps should be possible even when updating 1Ks of vertices (probably more) per second. Do this for whatever changed using dirty lists or something so you do not update everything to the GPU on each frame. This should be relatively fast if you using ArrayBuffers. 100% this can be done in JavaScript in a very fast fashion. It may only seem like it can not be done if you are doing JS poorly. Maybe people make the mistake of not using ArrayBuffers for everything and that makes it slow. The main limitation in JS is the lack of really great multithreading, but I do not think you need it here. If you want ultimate speed use WASM for the CPU-based updating of your geometry structures. Anyhow, you are mistaken in your current beliefs and it will hurt you going forward.
- Const-me 5y ago
  > I think you can tessellation on the CPU in an adaptive fashion (e.g. based on curvature or similar) and update that on a per frame (add, remove tessellation points) basis rather than re-tesselating from scratch each frame. The GPU’s hardware-implemented tessellation is (a) not compatible enough. It’s OK on Windows because Microsoft requires them for GPU vendors to declare the support of Direct3D 11. On the rest of the platforms, support across GPU vendors varies. And (b) doesn’t help much for 2D vector graphics. The hardware tessellation can be good for terrain, trees, or other triangle meshes in 3D space. Doesn’t help much for these Bezier curves/elliptical arcs for 2D shapes. Especially so for stroked paths. Counter-intuitively, stroked paths are harder to render than filled ones. The offset of Bezier spline is not representable as another Bezier spline. Also, strokes have more parameters on input: line caps, join types, dashes, miter limit, etc. > The main limitation in JS is the lack of really great multithreading Also lack of SIMD. Also, the code in general is slow compared to C++, C# and many other statically typed languages. It’s incredibly hard to generate fast code from very dynamic languages like JS or Python, where everything is a hash map. > I do not think you need it here. Here’s my code which offloads CPU-bound pieces of 2D rendering to other CPU cores: https://github.com/Const-me/Vrmac/tree/master/Vrmac/Draw/Tessellate https://github.com/Const-me/Vrmac/tree/master/Vrmac/Draw/Tes... Multithreading helped a lot.
jlokier 5y ago
Just in case it's useful: You actually can run C++ in the browser these days to do the intensive things, by using WebAssembly (WASM). It can call out to graphics APIs, so it might work for this project without changing the C++ much.

Const-me 5y ago

How are you rendering these vectors on Linux? I'm asking because AFAIK unlike Windows with Direct2D, Linux doesn't have GPU-targeted vector graphics libraries. I have once made my own one when I needed something similar: https://github.com/Const-me/Vrmac#vector-graphics-engine https://github.com/Const-me/Vrmac#vector-graphics-engine

borisdalstein 5y ago
I'm using 3D graphics APIs, OpenGL on Linux currently, but Vulkan will be an option later. I'm converting everything to triangles on the CPU and send to OpenGL. Note that the animation app actually needs to show 3D graphics for a 2D+time visualization which is part of the innovation in my research.
- Const-me 5y ago
  > I'm converting everything to triangles on the CPU and send to OpenGL Thanks, that’s what I thought. The library I have linked does the same thing. Only it’s either D3D12, or GLES 3.1 underneath.
  - borisdalstein 5y ago
    Wow, your library actually looks impressive! Yeah, I'm pretty much implementing all the same things.

ninetenfour 5y ago

I think you can tessellation on the CPU in an adaptive fashion (e.g. based on curvature or similar) and update that on a per frame (add, remove tessellation points) basis rather than re-tesselating from scratch each frame. The tessellation would just have weights from each control point. You can modify the vertices on the CPU, update the tessellation points and update those to the GPU. Get 60fps should be possible even when updating 1Ks of vertices (probably more) per second. Do this for whatever changed using dirty lists or something so you do not update everything to the GPU on each frame. This should be relatively fast if you using ArrayBuffers. 100% this can be done in JavaScript in a very fast fashion. It may only seem like it can not be done if you are doing JS poorly. Maybe people make the mistake of not using ArrayBuffers for everything and that makes it slow. The main limitation in JS is the lack of really great multithreading, but I do not think you need it here. If you want ultimate speed use WASM for the CPU-based updating of your geometry structures. Anyhow, you are mistaken in your current beliefs and it will hurt you going forward.

Const-me 5y ago
> I think you can tessellation on the CPU in an adaptive fashion (e.g. based on curvature or similar) and update that on a per frame (add, remove tessellation points) basis rather than re-tesselating from scratch each frame. The GPU’s hardware-implemented tessellation is (a) not compatible enough. It’s OK on Windows because Microsoft requires them for GPU vendors to declare the support of Direct3D 11. On the rest of the platforms, support across GPU vendors varies. And (b) doesn’t help much for 2D vector graphics. The hardware tessellation can be good for terrain, trees, or other triangle meshes in 3D space. Doesn’t help much for these Bezier curves/elliptical arcs for 2D shapes. Especially so for stroked paths. Counter-intuitively, stroked paths are harder to render than filled ones. The offset of Bezier spline is not representable as another Bezier spline. Also, strokes have more parameters on input: line caps, join types, dashes, miter limit, etc. > The main limitation in JS is the lack of really great multithreading Also lack of SIMD. Also, the code in general is slow compared to C++, C# and many other statically typed languages. It’s incredibly hard to generate fast code from very dynamic languages like JS or Python, where everything is a hash map. > I do not think you need it here. Here’s my code which offloads CPU-bound pieces of 2D rendering to other CPU cores: https://github.com/Const-me/Vrmac/tree/master/Vrmac/Draw/Tessellate https://github.com/Const-me/Vrmac/tree/master/Vrmac/Draw/Tes... Multithreading helped a lot.

jlokier 5y ago

Just in case it's useful: You actually can run C++ in the browser these days to do the intensive things, by using WebAssembly (WASM). It can call out to graphics APIs, so it might work for this project without changing the C++ much.