SoftGL

An opengl implementation using Software Rendering on the CPU.

Q&A

Why would I make this?

Because its fun to learn OpenGL from the wrong end.

What version of OpenGL does this support?

Somewhere around OpenGL1.4

Is it fast?

While i'm trying to make it fast, its not even close to something like a Geforce256 graphics card.

How do I use this?

You dont, and you shouldnt. It really just an experiment.

But really how do I use this?

1. Compile it.
2. Copy OpenGL32.dll, softgl_rast_reference.dll and softgl.cfg into your game folder.
3. Launch your game (which will most likely crash.)

Whats your goal?

When something like Doom3 is playable.

Is it conformant?

No.

Features

• Per triangle Mip-Mapping
• Perspective correct texture mapping
• Simple backend architecture
• Experimental OpenCL backend
• Not much else at the moment

Optimizations

• Affine mapping for small triangles
• Vectorizable edge based rendering
• 16x16 stamp rendering with fast culling
• Stamps coded in tight SSE

The future

• Support more old OpenGL games
• Fixed point UV interpolation
• More blend modes
• Use AVX stamps
• Multuithread the rasterizer
• JIT the raster stamps
• Improve the OpenCL backend
• Z-buffer at the stamp level for fast culling
• More optimizations
• Support more features
  • Alpha Test
  • Scissor
  • Texenv
  • Stencil Test
  • ...

Statistics

Stats from the quake 3 timedemo (default settings) invoked via quake3.exe +timedemo 1 +demo four.

1260 frames 51.0 seconds 24.7 fps 15.0/40.5/78.0/11.2 ms

Screenshots

These screenshots show the current state of progress on 15/04/2020.