Added ply loader and camera.

loader.go

@@ -1,11 +1,15 @@
 package goga
 
 import (
+	"bufio"
+	"errors"
 	"github.com/go-gl/gl/v4.5-core/gl"
 	"image"
 	"image/draw"
 	"image/png"
 	"os"
+	"strconv"
+	"strings"
 )
 
 // Loads textures from png files.
@@ -56,3 +60,232 @@ func (p *PngLoader) Load(file string) (Res, error) {
 func (p *PngLoader) Ext() string {
 	return "png"
 }
+
+// Standford ply file resource.
+type Ply struct {
+	name string
+	path string
+	ext  string
+
+	firstLine, data, hasVertex, hasTexCoord, hasNormal bool
+	elements, faces                                    int
+	indices                                            []uint32
+	vertices, texCoords, normals                       []float32
+
+	IndexBuffer, VertexBuffer, TexCoordBuffer, NormalBuffer *VBO
+}
+
+// Returns the name of this resource.
+func (p *Ply) GetName() string {
+	return p.name
+}
+
+// Sets the name of this resource.
+func (p *Ply) SetName(name string) {
+	p.name = name
+}
+
+// Returns the path of this resource.
+func (p *Ply) GetPath() string {
+	return p.path
+}
+
+// Sets the path of this resource.
+func (p *Ply) SetPath(path string) {
+	p.path = path
+}
+
+// Returns the file extension of this resource.
+func (p *Ply) GetExt() string {
+	return p.ext
+}
+
+// Sets the file extension of this resource.
+func (p *Ply) SetExt(ext string) {
+	p.ext = ext
+}
+
+// Loads ply files and creates VBOs within the Ply resource.
+// The indices must be present as triangles.
+// Expected type is float32. If it fails to parse, it will panic.
+type PlyLoader struct {
+	VboUsage uint32
+}
+
+func (p *PlyLoader) Load(file string) (Res, error) {
+	handle, err := os.Open(file)
+	defer handle.Close()
+
+	if err != nil {
+		return nil, err
+	}
+
+	scanner := bufio.NewScanner(handle)
+	ply := Ply{}
+	ply.indices = make([]uint32, 0)
+	ply.vertices = make([]float32, 0)
+	ply.texCoords = make([]float32, 0)
+	ply.normals = make([]float32, 0)
+
+	for scanner.Scan() {
+		line := strings.ToLower(scanner.Text())
+
+		if ply.data && ply.elements == 0 && ply.faces > 0 {
+			ply.faces--
+
+			if err := ply.parseIndices(line); err != nil {
+				return nil, err
+			}
+		}
+
+		if ply.data && ply.elements > 0 {
+			ply.elements--
+
+			if err := ply.parseData(line); err != nil {
+				return nil, err
+			}
+		}
+
+		if err := ply.parseHeader(line); err != nil {
+			return nil, err
+		}
+
+		ply.firstLine = false
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	index, vertex, texCoord, normal := ply.createVBOs(p.VboUsage)
+	ply.IndexBuffer = index
+	ply.VertexBuffer = vertex
+	ply.TexCoordBuffer = texCoord
+	ply.NormalBuffer = normal
+
+	return &ply, nil
+}
+
+func (p *Ply) createVBOs(vboUsage uint32) (*VBO, *VBO, *VBO, *VBO) {
+	index := NewVBO(gl.ELEMENT_ARRAY_BUFFER)
+	index.Fill(gl.Ptr(p.indices), 4, len(p.indices), vboUsage)
+
+	vertex := NewVBO(gl.ARRAY_BUFFER)
+	vertex.Fill(gl.Ptr(p.vertices), 4, len(p.vertices), vboUsage)
+
+	var texCoord, normal *VBO
+
+	if p.hasTexCoord {
+		texCoord = NewVBO(gl.ARRAY_BUFFER)
+		texCoord.Fill(gl.Ptr(p.texCoords), 4, len(p.texCoords), vboUsage)
+	}
+
+	if p.hasNormal {
+		normal = NewVBO(gl.ARRAY_BUFFER)
+		normal.Fill(gl.Ptr(p.normals), 4, len(p.normals), vboUsage)
+	}
+
+	return index, vertex, texCoord, normal
+}
+
+func (p *Ply) parseHeader(line string) error {
+	if p.firstLine && line != "ply" { // make sure it's a ply file
+		return errors.New("File is not of type ply")
+	} else if strings.Contains(line, "element vertex") { // number of elements
+		elements, err := strconv.Atoi(line[15:])
+
+		if err != nil {
+			return errors.New("Elements could not be parsed")
+		}
+
+		p.elements = elements
+	} else if strings.Contains(line, "property float") {
+		line = line[15:]
+
+		if line == "x" || line == "y" || line == "z" {
+			p.hasVertex = true
+		} else if line == "nx" || line == "ny" || line == "nz" {
+			p.hasNormal = true
+		} else if line == "s" || line == "t" {
+			p.hasTexCoord = true
+		}
+	} else if strings.Contains(line, "element face") { // number of faces
+		faces, err := strconv.Atoi(line[13:])
+
+		if err != nil {
+			return errors.New("Faces could not be parsed")
+		}
+
+		p.faces = faces
+	} else if strings.Contains(line, "end_header") {
+		p.data = true
+	}
+
+	return nil
+}
+
+func (p *Ply) parseData(line string) error {
+	if !p.hasVertex {
+		return errors.New("ply must have vertex data")
+	}
+
+	parts := strings.Split(line, " ")
+	i := 0
+
+	p.vertices = append(p.vertices, parseFloat32(parts[0]))
+	p.vertices = append(p.vertices, parseFloat32(parts[1]))
+	p.vertices = append(p.vertices, parseFloat32(parts[2]))
+
+	if p.hasNormal {
+		i += 3
+
+		p.normals = append(p.normals, parseFloat32(parts[3]))
+		p.normals = append(p.normals, parseFloat32(parts[4]))
+		p.normals = append(p.normals, parseFloat32(parts[5]))
+	}
+
+	if p.hasTexCoord {
+		p.texCoords = append(p.texCoords, parseFloat32(parts[3+i]))
+		p.texCoords = append(p.texCoords, parseFloat32(parts[4+i]))
+	}
+
+	return nil
+}
+
+func parseFloat32(str string) float32 {
+	float, err := strconv.ParseFloat(str, 32)
+
+	if err != nil {
+		panic(err)
+	}
+
+	return float32(float)
+}
+
+func (p *Ply) parseIndices(line string) error {
+	parts := strings.Split(line, " ")
+
+	if len(parts) != 4 || parts[0] != "3" {
+		return errors.New("Expected triangles for indices")
+	}
+
+	p.indices = append(p.indices, parseUint32(parts[1]))
+	p.indices = append(p.indices, parseUint32(parts[2]))
+	p.indices = append(p.indices, parseUint32(parts[3]))
+
+	return nil
+}
+
+func parseUint32(str string) uint32 {
+	i, err := strconv.Atoi(str)
+
+	if err != nil {
+		panic(err)
+	}
+
+	return uint32(i)
+}
+
+func (p *PlyLoader) Ext() string {
+	return "ply"
+}