Shaders: How to draw high fidelity graphics with just x and y coordinates

Post by Kiro » Sun, Nov 23, 2025, 4:24 PM UTC

dahart wrote: post #28

GuB-42 wrote: post #16

That, I think, is the most unintuitive part about writing fragment shaders. The idea that you take a couple of coordinates and output a color. Compared to traditional drawing, as with a pen and paper, you have to think in reverse. For example if you want to draw a square with a pen, you put your pen where the square is, draw the outlines, than fill it up, with a shader, for each pixel, you look at where you are, calc…

I think what you’re describing is the difference between raster and vector graphics, and doesn’t reflect on shaders directly. It always depends on your goals, of course. The goal of drawing with a pen is to draw outlines, but the goal behind rasterizing or ray tracing, and shading, is not to draw outlines, but often to render 3d scenes with physically based materials. Achieving that goal with a pen is extremely diffi…

Post by jsheard » Sun, Nov 23, 2025, 4:36 PM UTC

kasool wrote: post #24

socalgal2 wrote: post #19

Nice article, though the diagram showing [OpenGL] [WebGL] [WebGPU] being built on Vulkan and then from Vulkan to D3D12 and Metal is wrong. WebGL and WebGPU go directly to D3D and Metal, they do not go through Vulkan first Also, Vulkan is labeled as Open Source. It is not open source. The are other mistakes in that area as well. It claims WebGPU is limited to Browsers. It is, not. WebGPU is available as both a C++ (Da…

To elaborate on this, Vulkan is an open _standard_ whose many implementations (user mode driver) may or may not be open source. Vulkan is just a header file, it's up to the various independent hardware vendors (IHVs) to implement it for their platform. Also a small correction: Vulkan actually _does_ run Apple platforms (via Vulkan-to-Metal translation) using MoltenVK and the new KosmicKrisp driver, and it works quite…

Post by pengaru » Sun, Nov 23, 2025, 4:37 PM UTC

Scene_Cast2 wrote: post #14

For anyone looking for some IDEs to tinker around with shaders: * shadertoy - in-browser, the most popular and easiest to get started with * Shadron - my personal preference due to ease of use and high capability, but a bit niche * SHADERed - the UX can take a bit of getting used to, but it gets the job done * KodeLife - heard of it, never tried it

Post by dahart » Sun, Nov 23, 2025, 4:42 PM UTC

socalgal2 wrote: post #19

Nice article, though the diagram showing [OpenGL] [WebGL] [WebGPU] being built on Vulkan and then from Vulkan to D3D12 and Metal is wrong. WebGL and WebGPU go directly to D3D and Metal, they do not go through Vulkan first Also, Vulkan is labeled as Open Source. It is not open source. The are other mistakes in that area as well. It claims WebGPU is limited to Browsers. It is, not. WebGPU is available as both a C++ (Da…

Post by dahart » Sun, Nov 23, 2025, 4:45 PM UTC

Kiro wrote: post #31

dahart wrote: post #28

Earlier quoted context omitted.

I think what you’re describing is the difference between raster and vector graphics, and doesn’t reflect on shaders directly. It always depends on your goals, of course. The goal of drawing with a pen is to draw outlines, but the goal behind rasterizing or ray tracing, and shading, is not to draw outlines, but often to render 3d scenes with physically based materials. Achieving that goal with a pen is extremely diffi…

I think their explanation is great. The shader is run on all the pixels within the quad and your shader code needs to figure out if the pixel is within the shape you want to draw or not. Compared to just drawing it pixel by pixel if you do it by pen or on the CPU. For a red line between A and B: CPU/pen: for each pixel between A and B: draw red GPU/shader: for all pixels: draw red if it's on the intersection between…