Add docstrings

1 files changed, 9 insertions, 4 deletions

diff --git a/stl.go b/stl.go
index 851a003..512d262 100644
--- a/stl.go
+++ b/stl.go
@@ -13,16 +13,17 @@ import (
 	"math"
 )
 
-// representation of binary STL file content
+// StlModel is the Go-internal representation of a STL model.
 type StlModel struct {
 	header []byte
 	numberOfTriangles uint32
 	surface Surface
 }
 
+// Vector3 is a three-dimensional vector based on 32 bit floats.
 type Vector3 [3]float32
 
-// read and parse a given binary STL file
+// ReadBinaryStlFile reads and parses a given binary STL file.
 func ReadBinaryStlFile(filePath string) (StlModel, error) {
 
 	fileContent, err := ioutil.ReadFile(filePath)
@@ -50,8 +51,8 @@ func ReadBinaryStlFile(filePath string) (StlModel, error) {
 	return model,nil
 }
 
-// parse the 50 bytes of the STL file representing a triangle (surface normal
-// is ignored)
+// ParseBinaryStlTriangle parses the 50 bytes of the STL file representing a
+// triangle (surface normal is ignored).
 func ParseBinaryStlTriangle(data []byte) *Triangle {
 
 	// FIXME: This function should only accept 50 byte slices/arrays
@@ -89,6 +90,7 @@ func ParseBinaryStlTriangle(data []byte) *Triangle {
 	return triangle
 }
 
+// toVertices converts a STL model into vertices suitable for OpenGL rendering.
 func (stl StlModel) toVertices() (vertex_position []float32,
 	vertex_normal []float32) {
 
@@ -135,12 +137,14 @@ func (stl StlModel) toVertices() (vertex_position []float32,
 	return vertex_position, vertex_normal
 }
 
+// divideScalar divides a three-dimensional vector by a scalar.
 func (vector *Vector3) divideScalar(scalar float32) {
 	vector[0] = vector[0] / scalar
 	vector[1] = vector[1] / scalar
 	vector[2] = vector[2] / scalar
 }
 
+// subtract subtracts vectorB from vectorA.
 func (vectorA Vector3) subtract(vectorB Vector3) (vectorC Vector3) {
 
 	vectorC[0] = vectorA[0] - vectorB[0]
@@ -150,6 +154,7 @@ func (vectorA Vector3) subtract(vectorB Vector3) (vectorC Vector3) {
 	return vectorC
 }
 
+// crossProduct returns the cross product vectorA x vectorB.
 func (vectorA Vector3) crossProduct(vectorB Vector3) (vectorC Vector3) {
 
 	vectorC[0] = vectorA[1] * vectorB[2] - vectorA[2] * vectorB[1]