179 lines
No EOL
3.5 KiB
Go
179 lines
No EOL
3.5 KiB
Go
package main
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import "fmt" // for IO and standard library
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import "os" // for handling the progress bar
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import "math" // for maths
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// ================ VEC3 CLASS =====================
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type Vec3 struct {
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E [3]float32
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}
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//Basic vector functions
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func NewVec3(e0, e1, e2 float32) Vec3 {
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return Vec3{E: [3]float32{e0, e1, e2}}
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}
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func (v Vec3) X() float32 {
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return v.E[0]
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}
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// can be executed as v.X() in main
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func (v Vec3) Y() float32 {
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return v.E[1]
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}
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func (v Vec3) Z() float32 {
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return v.E[2]
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}
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func (v Vec3) Neg() Vec3 {
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return NewVec3(-v.E[0], -v.E[1], -v.E[2])
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}
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func (v Vec3) Get(i int) float32 {
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return v.E[i]
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}
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func (v *Vec3) Set(i int, val float32) {
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v.E[i] = val
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}
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func (v *Vec3) Add(v2 Vec3) {
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v.E[0] += v2.E[0]
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v.E[1] += v2.E[1]
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v.E[2] += v2.E[2]
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}
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func (v *Vec3) Mult(t float32) {
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v.E[0] *= t
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v.E[1] *= t
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v.E[2] *= t
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}
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func (v *Vec3) Div(t float32) {
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if t != 0 {
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v.E[0] /= t
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v.E[1] /= t
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v.E[2] /= t
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}
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}
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func (v Vec3) Length() float32 {
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return float32(math.Sqrt(float64(v.E[0]*v.E[0] + v.E[1]*v.E[1] + v.E[2]*v.E[2])))
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}
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// Vector utility functions
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func (v Vec3) String() string {
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return fmt.Sprintf("%v %v %v", v.E[0], v.E[1], v.E[2])
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}
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func (v *Vec3) Sub(v2 Vec3) {
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v.E[0] -= v2.E[0]
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v.E[1] -= v2.E[1]
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v.E[2] -= v2.E[2]
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}
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func (v *Vec3) MultVec(v2 Vec3) {
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v.E[0] *= v2.E[0]
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v.E[1] *= v2.E[1]
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v.E[2] *= v2.E[2]
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}
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func (v *Vec3) DivVec(v2 Vec3) {
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v.E[0] /= v2.E[0]
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v.E[1] /= v2.E[1]
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v.E[2] /= v2.E[2]
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}
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func Dot(v1 Vec3, v2 Vec3) float32 {
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return (v1.E[0]*v2.E[0] + v1.E[1]*v2.E[1] + v1.E[2]*v2.E[2])
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}
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func Cross(v1 Vec3, v2 Vec3) Vec3 {
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return NewVec3(v1.E[1]*v2.E[2] - v1.E[2]*v2.E[1],
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v1.E[2]*v2.E[0] - v1.E[0]*v2.E[2],
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v1.E[0]*v2.E[1] - v1.E[1]*v2.E[0])
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}
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func Unit_vector(v Vec3) Vec3 {
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v.Div(v.Length())
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return v
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}
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// ============== COLOUR CLASS ==============
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func Write_color(v Vec3) {
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fmt.Println(int(255.999*v.E[0]), int(255.999*v.E[1]), int(255.999*v.E[2]))
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}
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// ============== RAY CLASS =================
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type Point3 Vec3
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type Ray struct {
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Orig Point3
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Dir Vec3
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}
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func NewRay(orig Point3, dir Vec3) *Ray {
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return &Ray{Orig: orig, Dir: dir}
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}
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func (r *Ray) Origin() Point3 {
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return r.Orig
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}
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func (r *Ray) Direction() Vec3 {
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return r.Dir
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}
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func (r *Ray) At(t float32) Point3 {
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return Point3{
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X: r.Orig.X + t*r.Dir.X,
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Y: r.Orig.Y + t*r.Dir.Y,
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Z: r.Orig.Z + t*r.Dir.Z
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}
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}
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// =============== MAIN =====================
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func main() {
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// Image
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var aspect_ratio := 16.0 / 9.0;
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var image_width int = 400;
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var image_height int = int(image_width / aspect_ratio)
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if image_height < 1 {
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image_height = 1
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}
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// Viewport
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var viewport_height := 2.0
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var viewport_width := viewport_height * float32(image_width/image_height)
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// Rendering
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fmt.Println("P3")
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fmt.Println(image_width, " ", image_height, "\n255")
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for j := 0; j < image_height; j++ {
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fmt.Fprintf(os.Stderr, "\rScanlines remaining: %d ", image_height-j)
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for i := 0; i < image_width; i++ {
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// r := float32(i) / float32(image_width - 1)
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// g := float32(j) / float32(image_height-1)
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// b := 0
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// ir := int(r * 256)
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// ig := int(g * 256)
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// ib := int(b * 256)
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// fmt.Println(ir, " ", ig, " ", ib)
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pixel_colour := NewVec3(float32(i) / float32(image_width - 1), float32(j) / float32(image_height-1), 0)
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Write_color(pixel_colour)
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}
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}
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// INFO: The pixels are written out in rows.
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// Image file can be created with
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// go run main.go > image.ppm
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} |