3dtrial/tinyrender2/main.go

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2024-07-26 21:32:20 +00:00
package main
import (
"flag"
"fmt"
"log"
"os"
"runtime/pprof" // For performance profiling (unnecessary)
)
const (
Width = 512
Height = 512
ObjectFile = "head.obj"
Repeat = 1_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)
log.Printf("Running render")
halfwidth := float32(fb.Width / 2)
halfheight := float32(fb.Height / 2)
var x [3]int
var y [3]int
var hi = int(fb.Height - 1)
for range Repeat {
for _, f := range o.Faces {
// Precompute perspective for vertices to save time. Notice Z
// is not considered: is this orthographic projection? Yeah probably...
for i := range 3 { // Triangles, bro
x[i] = int((f[i].X + 1) * halfwidth)
y[i] = hi - int((f[i].Y+1)*halfheight)
}
Bresenham2(&fb, 0xFFFFFF, x[0], y[0], x[1], y[1])
Bresenham2(&fb, 0xFFFFFF, x[1], y[1], x[2], y[2])
Bresenham2(&fb, 0xFFFFFF, x[2], y[2], x[0], y[0])
}
// Just draw a simple line (a million times or something)
// // 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")
}