136 lines
3.8 KiB
Go
136 lines
3.8 KiB
Go
package main
|
|
|
|
import (
|
|
"flag"
|
|
"fmt"
|
|
"image"
|
|
"log"
|
|
//"math"
|
|
//"math/rand"
|
|
"os"
|
|
"runtime/pprof" // For performance profiling (unnecessary)
|
|
|
|
_ "image/jpeg"
|
|
)
|
|
|
|
const (
|
|
Width = 512
|
|
Height = 512
|
|
NearClip = 0.1
|
|
FarClip = 5 // Because the head is so small and close
|
|
ObjectFile = "head.obj"
|
|
TextureFile = "head.jpg"
|
|
)
|
|
|
|
func must(err error) {
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
}
|
|
|
|
// However flag works... idk
|
|
var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")
|
|
var dozbuf = flag.Bool("zbuffer", false, "Write zbuffer instead of image")
|
|
var p6file = flag.String("p6file", "", "Output binary ppm to given file instead")
|
|
var fov = flag.Float64("fov", 90, "Horizontal FOV in degrees")
|
|
var xofs = flag.Float64("xofs", 0, "Offset image by x")
|
|
var zofs = flag.Float64("zofs", -1.5, "Offset image by z (should be negative)")
|
|
var repeat = flag.Int("repeat", 60, "Amount of times to repeat render")
|
|
|
|
// var zcuthigh = flag.Float64("zcuthigh", math.MaxFloat32, "High cutoff for z (values above this will be removed)")
|
|
// var zcutlow = flag.Float64("zcutlow", -math.MaxFloat32, "Low cutoff for z (values below are removed)")
|
|
|
|
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, texture %s", ObjectFile, TextureFile)
|
|
|
|
of, err := os.Open(ObjectFile)
|
|
must(err)
|
|
defer of.Close()
|
|
o, err := ParseObj(of)
|
|
must(err)
|
|
|
|
jf, err := os.Open(TextureFile)
|
|
must(err)
|
|
defer jf.Close()
|
|
timg, _, err := image.Decode(jf)
|
|
must(err)
|
|
texture := NewTexture(timg, 4)
|
|
|
|
log.Printf("Running render")
|
|
|
|
light := Vec3f{0, 0, -1}
|
|
|
|
var projection Mat44f
|
|
var worldToCamera Mat44f
|
|
projection.SetProjection(float32(*fov), NearClip, FarClip)
|
|
worldToCamera.SetTranslation(float32(*xofs), 0, float32(*zofs))
|
|
|
|
// Premultiply all the translation/etc matrices. Why do we do world to camera THEN
|
|
// projection? I guess that makes sense actually, oops... projection is the last step.
|
|
screenmat := worldToCamera.Multiply(&projection)
|
|
|
|
halfwidth := float32(fb.Width / 2)
|
|
halfheight := float32(fb.Height / 2)
|
|
var sc [3]Vertex
|
|
var hi = float32(fb.Height - 1)
|
|
for range *repeat {
|
|
fb.ResetZBuffer()
|
|
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
|
|
fp := screenmat.MultiplyPoint3(f[i].Pos)
|
|
sc[i] = f[i]
|
|
sc[i].Pos.X = (fp.X + 1) * halfwidth
|
|
sc[i].Pos.Y = hi - (fp.Y+1)*halfheight
|
|
sc[i].Pos.Z = fp.Z
|
|
// NOTE: WE USE NEGATIVE Z BECAUSE IT'S SUPPOSED TO BE DISTANCE! AS-IS, CLOSER
|
|
// POINTS HAVE HIGHER Z VLAUES
|
|
// sc[i].Pos.Z = -fp.Z // Pull Z value directly. This is fine, our z-buffer is currently float32
|
|
}
|
|
|
|
l1 := f[2].Pos.Sub(f[0].Pos)
|
|
n := l1.CrossProduct(f[1].Pos.Sub(f[0].Pos))
|
|
n = n.Normalize()
|
|
intensity := n.MultSimp(&light)
|
|
if intensity > 0 {
|
|
Triangle3t(&fb, &texture, intensity, sc[0], sc[1], sc[2])
|
|
//Triangle3(&fb, uint(rand.Int()), sc[0], sc[1], sc[2])
|
|
//Triangle1(&fb, uint(rand.Int()), sc[0].ToVec2i(), sc[1].ToVec2i(), sc[2].ToVec2i())
|
|
//Triangle2(&fb, 0xFFFFFF, sc[0], sc[1], sc[2])
|
|
}
|
|
}
|
|
}
|
|
|
|
if *dozbuf {
|
|
log.Printf("Exporting zbuffer ppm to stdout")
|
|
fmt.Print(fb.ZBuffer_ExportPPM())
|
|
} else {
|
|
if *p6file != "" {
|
|
err := os.WriteFile(*p6file, fb.ExportPPMP6(), 0660)
|
|
must(err)
|
|
} else {
|
|
log.Printf("Exporting ppm to stdout")
|
|
fmt.Print(fb.ExportPPM())
|
|
}
|
|
}
|
|
|
|
log.Printf("Program end")
|
|
}
|