3dtrial/tinyrender1/main.go

package main

import (
	"flag"
	"fmt"
	"log"
	"os"
	"runtime/pprof" // For performance whatever
	// "github.com/udhos/gwob"
)

const (
	Width      = 512
	Height     = 512
	ObjectFile = "head.obj"
	//LineRepeat = 1_000_000
)

func must(err error) {
	if err != nil {
		panic(err)
	}
}

// However flag works... idk
var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")

func main() {
	log.Printf("Program start")

	// Little section for doing cpu profiling. I guess that's all you have to do?
	flag.Parse()
	if *cpuprofile != "" {
		log.Printf("CPU profiling requested, write to %s", *cpuprofile)
		f, err := os.Create(*cpuprofile)
		must(err)
		defer f.Close()
		err = pprof.StartCPUProfile(f)
		must(err)
		defer pprof.StopCPUProfile()
	}

	fb := NewFramebuffer(Width, Height)

	log.Printf("Loading obj %s", ObjectFile)

	of, err := os.Open(ObjectFile)
	must(err)
	defer of.Close()
	o, err := ParseObj(of)
	must(err)
	// gwobopts := &gwob.ObjParserOptions {}
	// o, err := gwob.NewObjFromFile(ObjectFile, gwobopts)
	// must(err)

	log.Printf("Running render")

	for _, f := range o.Faces {
		log.Printf("%v", f)
		for i := range 3 { // Triangles, bro
			v0 := f[i]
			v1 := f[(i+1)%3]
			x0 := int((v0.X + 1) * float32(fb.Width/2))
			y0 := int((v0.Y + 1) * float32(fb.Height/2))
			x1 := int((v1.X + 1) * float32(fb.Width/2))
			y1 := int((v1.Y + 1) * float32(fb.Height/2))
			Bresenham2(&fb, 0xFFFFFF, x0, int(fb.Height)-y0, x1, int(fb.Height)-y1)
		}
	}

	// Just draw a simple line (a million times or something)
	// for range LineRepeat {
	// 	// LineDumb5(&fb, 0xFFFFFF, 100, 100, 350, 200)
	// 	// LineDumb5(&fb, 0xFF0000, 120, 100, 200, 350)
	// 	// LineDumb5(&fb, 0xFF0000, 350, 200, 100, 100) // backward first line
	// 	Bresenham2(&fb, 0xFFFFFF, 100, 100, 350, 200)
	// 	Bresenham2(&fb, 0xFF0000, 120, 100, 200, 350)
	// 	Bresenham2(&fb, 0xFF0000, 350, 200, 100, 100) // backward first line
	// }

	log.Printf("Exporting ppm to stdout")
	fmt.Print(fb.ExportPPM())

	log.Printf("Program end")
}