94 lines
2.2 KiB
Go
94 lines
2.2 KiB
Go
package main
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import (
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"flag"
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"fmt"
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"log"
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"os"
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"runtime/pprof" // For performance profiling (unnecessary)
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)
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const (
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Width = 512
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Height = 512
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FOV = 110
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NearClip = 0.1
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FarClip = 2 // Because the head is so small and close
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ObjectFile = "head.obj"
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Repeat = 1000
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)
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func must(err error) {
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if err != nil {
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panic(err)
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}
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}
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// However flag works... idk
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var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")
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func main() {
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log.Printf("Program start")
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// Little section for doing cpu profiling. I guess that's all you have to do?
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flag.Parse()
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if *cpuprofile != "" {
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log.Printf("CPU profiling requested, write to %s", *cpuprofile)
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f, err := os.Create(*cpuprofile)
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must(err)
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defer f.Close()
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err = pprof.StartCPUProfile(f)
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must(err)
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defer pprof.StopCPUProfile()
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}
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fb := NewFramebuffer(Width, Height)
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log.Printf("Loading obj %s", ObjectFile)
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of, err := os.Open(ObjectFile)
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must(err)
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defer of.Close()
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o, err := ParseObj(of)
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must(err)
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log.Printf("Running render")
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halfwidth := float32(fb.Width / 2)
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halfheight := float32(fb.Height / 2)
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var projection Mat44f
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var worldToCamera Mat44f
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projection.SetProjection(FOV, NearClip, FarClip)
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worldToCamera.SetIdentity()
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worldToCamera.Set(2, 3, -1) // Get farther away from the face
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var x [3]int
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var y [3]int
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var c [3]uint
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var hi = int(fb.Height - 1)
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for range Repeat {
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for _, f := range o.Faces {
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// Precompute perspective for vertices to save time. Notice Z
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// is not considered: is this orthographic projection? Yeah probably...
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for i := range 3 { // Triangles, bro
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// The ONLY difference between this and the non-perspective is this multiplication.
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// Is this really all that's required?
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fp := worldToCamera.MultiplyPoint3(f[i])
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fp = projection.MultiplyPoint3(fp)
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x[i] = int((fp.X + 1) * halfwidth)
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y[i] = hi - int((fp.Y+1)*halfheight)
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c[i] = Col2Uint(byte(0xFF*fp.Z), byte(0xFF*fp.Z), byte(0xFF*fp.Z))
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}
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Bresenham2(&fb, c[0], x[0], y[0], x[1], y[1])
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Bresenham2(&fb, c[1], x[1], y[1], x[2], y[2])
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Bresenham2(&fb, c[2], x[2], y[2], x[0], y[0])
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}
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}
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log.Printf("Exporting ppm to stdout")
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fmt.Print(fb.ExportPPM())
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log.Printf("Program end")
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}
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