softwarerenderer's Introduction

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

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);