C++ Software Renderer/Rasterizer

This project implements a C++ software renderer/rasterizer with vertex- and pixel shader support.

Features

• Generic vertex arrays for arbitrary data in the vertex processing stage.
• Internal vertex cache for better vertex processing.
• Affine and perspective correct per vertex parameter interpolation.
• Vertex and pixel shaders written in C++ using some C++ template magic.

Resources

• Triangle Rasterization
• Accelerated Half-Space Triangle Rasterization

Example

#include "Renderer.h"

// Define a pixel shader
class PixelShader : public PixelShaderBase<PixelShader> {
public:
  static const bool InterpolateZ = true;
  static const bool InterpolateW = true;

  // Number of affine/linear variables used.
  static const int AVarCount = 3;

  // Number of perspective correct variables used.
  static const int PVarCount = 2;

  static void drawPixel(const PixelData &p)
  {
      ...
  }
};

// Define a vertex shader
class VertexShader : public VertexShaderBase<VertexShader> {
public:
  // Number of input vertex attributes used.
  static const int AttribCount = 1;

  static void processVertex(VertexShaderInput in, VertexShaderOutput *out)
  {
    // Write result to out.
    ...
  }
};

// Use the renderer
Rasterizer r;
VertexProcessor v(&r);

r.setRasterMode(RasterMode::Span);
r.setScissorRect(0, 0, 640, 480);
r.setPixelShader<PixelShader>();

v.setViewport(0, 0, 640, 480);
v.setCullMode(CullMode::CW);
v.setVertexShader<VertexShader>();

// Draw
v.setVertexAttribPointer(0, sizeof(VertexData), vertexData);
v.drawElements(DrawMode::Triangle, indexData.size(), indexData);

License

This code is licensed under the MIT License (see LICENSE).