67 lines
1.5 KiB
Go
67 lines
1.5 KiB
Go
package main
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// This reads obj files?
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import (
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"bufio"
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"fmt"
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"io"
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"strings"
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)
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type Vec3f struct {
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X, Y, Z float32
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}
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type Facef [3]Vec3f
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type ObjModel struct {
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Vertices []Vec3f
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Faces []Facef
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}
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func ParseObj(reader io.Reader) (*ObjModel, error) {
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result := ObjModel{
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Vertices: make([]Vec3f, 0),
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Faces: make([]Facef, 0),
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}
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scanner := bufio.NewScanner(reader)
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for scanner.Scan() {
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// Scan a line
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line := strings.Trim(scanner.Text(), " \t")
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// Find the first "item", whatever that is. This also gets rid of comments
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// since we just don't use lines that start with # (no handler
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var t string
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_, err := fmt.Sscan(line, t)
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if err != nil {
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return nil, err
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}
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line = line[len(t):]
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if t == "v" {
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// Read a vertex, should be just three floats
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var vertex Vec3f
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_, err := fmt.Sscan(line, vertex.X, vertex.Y, vertex.Z)
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if err != nil {
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return nil, err
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}
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result.Vertices = append(result.Vertices, vertex)
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} else if t == "f" {
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// Read a face; in our example, it's always three sets.
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// For THIS example, we throw away those other values
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var face Facef
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for i := range 3 {
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var vi, ti0, ti1 int
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_, err := fmt.Sscanf(line, "%d/%d/%d", vi, ti0, ti1)
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if err != nil {
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return nil, err
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}
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if vi > len(result.Vertices) || vi < 1 {
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return nil, fmt.Errorf("Face vertex index out of bounds: %d", vi)
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}
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face[i] = result.Vertices[vi-1]
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}
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result.Faces = append(result.Faces, face)
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}
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}
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return &result, nil
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}
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