so sloooow
This commit is contained in:
parent
37c6ce73a8
commit
0a0d4436e7
@ -56,9 +56,9 @@ func main() {
|
|||||||
//halfwidth := float32(fb.Width / 2)
|
//halfwidth := float32(fb.Width / 2)
|
||||||
//halfheight := float32(fb.Height / 2)
|
//halfheight := float32(fb.Height / 2)
|
||||||
for range Repeat {
|
for range Repeat {
|
||||||
Triangle1(&fb, 0xFF0000, Vec2i{10, 70}, Vec2i{50, 160}, Vec2i{70, 80})
|
Triangle2(&fb, 0xFF0000, Vec2i{10, 70}, Vec2i{50, 160}, Vec2i{70, 80})
|
||||||
Triangle1(&fb, 0xFFFFFF, Vec2i{180, 50}, Vec2i{150, 1}, Vec2i{70, 180})
|
Triangle2(&fb, 0xFFFFFF, Vec2i{180, 50}, Vec2i{150, 1}, Vec2i{70, 180})
|
||||||
Triangle1(&fb, 0x00FF00, Vec2i{180, 150}, Vec2i{120, 160}, Vec2i{130, 180})
|
Triangle2(&fb, 0x00FF00, Vec2i{180, 150}, Vec2i{120, 160}, Vec2i{130, 180})
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
@ -17,6 +17,10 @@ type Vec2i struct {
|
|||||||
X, Y int
|
X, Y int
|
||||||
}
|
}
|
||||||
|
|
||||||
|
type Vec2f struct {
|
||||||
|
X, Y float32
|
||||||
|
}
|
||||||
|
|
||||||
type Facef [3]Vec3f
|
type Facef [3]Vec3f
|
||||||
|
|
||||||
type ObjModel struct {
|
type ObjModel struct {
|
||||||
@ -24,6 +28,14 @@ type ObjModel struct {
|
|||||||
Faces []Facef
|
Faces []Facef
|
||||||
}
|
}
|
||||||
|
|
||||||
|
func (vi *Vec2i) ToF() Vec2f {
|
||||||
|
return Vec2f{float32(vi.X), float32(vi.Y)}
|
||||||
|
}
|
||||||
|
|
||||||
|
// func CrossProduct(v0, v1 Vec3f) Vec3f {
|
||||||
|
//
|
||||||
|
// }
|
||||||
|
|
||||||
// Parse an obj file at the given reader. Only handles v and f right now
|
// Parse an obj file at the given reader. Only handles v and f right now
|
||||||
func ParseObj(reader io.Reader) (*ObjModel, error) {
|
func ParseObj(reader io.Reader) (*ObjModel, error) {
|
||||||
result := ObjModel{
|
result := ObjModel{
|
||||||
|
@ -1,6 +1,7 @@
|
|||||||
package main
|
package main
|
||||||
|
|
||||||
import (
|
import (
|
||||||
|
//"log"
|
||||||
"math"
|
"math"
|
||||||
)
|
)
|
||||||
|
|
||||||
@ -98,3 +99,80 @@ func Triangle1(fb *Framebuffer, color uint, v0 Vec2i, v1 Vec2i, v2 Vec2i) {
|
|||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
// How does this work? Compare with your
|
||||||
|
// other barycentric function (in a different repo). In the original
|
||||||
|
// cpp code, they used an overloaded operator ^ to mean cross product
|
||||||
|
func Barycentric(v0, v1, v2, p Vec2i) Vec3f {
|
||||||
|
// WARN: Just not doing this one
|
||||||
|
u := Vec3f{}
|
||||||
|
if math.Abs(float64(u.Z)) < 1 {
|
||||||
|
return Vec3f{-1, 1, 1}
|
||||||
|
}
|
||||||
|
return Vec3f{1 - (u.X+u.Y)/u.Z, u.Y / u.Z, u.X / u.Z}
|
||||||
|
}
|
||||||
|
|
||||||
|
// Figure out the minimum bounding box for a triangle defined by
|
||||||
|
// these vertices. Returns the top left and bottom right points,
|
||||||
|
// inclusive
|
||||||
|
func ComputeBoundingBox(v0, v1, v2 Vec2i) (Vec2i, Vec2i) {
|
||||||
|
return Vec2i{min(v0.X, v1.X, v2.X), min(v0.Y, v1.Y, v2.Y)},
|
||||||
|
Vec2i{max(v0.X, v1.X, v2.X), max(v0.Y, v1.Y, v2.Y)}
|
||||||
|
}
|
||||||
|
|
||||||
|
// The generic edge function, returning positive if P is on the right side of
|
||||||
|
// the line drawn between v1 and v2. This is counter clockwise
|
||||||
|
func EdgeFunction(v1, v2, p Vec2f) float32 {
|
||||||
|
return (p.X-v1.X)*(v2.Y-v1.Y) - (p.Y-v1.Y)*(v2.X-v1.X)
|
||||||
|
}
|
||||||
|
|
||||||
|
// This computes the x and y per-pixel increment for the line going
|
||||||
|
// between v1 and v2 (also counter clockwise)
|
||||||
|
func EdgeIncrement(v1, v2 Vec2f) (float32, float32) {
|
||||||
|
return (v2.Y - v1.Y), -(v2.X - v1.X)
|
||||||
|
}
|
||||||
|
|
||||||
|
func Triangle2(fb *Framebuffer, color uint, v0 Vec2i, v1 Vec2i, v2 Vec2i) {
|
||||||
|
boundsTL, boundsBR := ComputeBoundingBox(v0, v1, v2)
|
||||||
|
const expand = (2 << 12)
|
||||||
|
//log.Print(boundsTL, boundsBR)
|
||||||
|
v0f := v0.ToF()
|
||||||
|
v1f := v1.ToF()
|
||||||
|
v2f := v2.ToF()
|
||||||
|
// Where to start our scanning
|
||||||
|
pstart := Vec2f{float32(boundsTL.X) + 0.5, float32(boundsTL.Y) + 0.5}
|
||||||
|
// parea := EdgeFunction(v0f, v1f, v2f)
|
||||||
|
// invarea := 1 / parea
|
||||||
|
w0_y := int(expand * EdgeFunction(v1f, v2f, pstart))
|
||||||
|
w1_y := int(expand * EdgeFunction(v2f, v0f, pstart))
|
||||||
|
w2_y := int(expand * EdgeFunction(v0f, v1f, pstart))
|
||||||
|
w0_xit, w0_yit := EdgeIncrement(v1f, v2f)
|
||||||
|
w1_xit, w1_yit := EdgeIncrement(v2f, v0f)
|
||||||
|
w2_xit, w2_yit := EdgeIncrement(v0f, v1f)
|
||||||
|
w0_xi := int(expand * w0_xit)
|
||||||
|
w0_yi := int(expand * w0_yit)
|
||||||
|
w1_xi := int(expand * w1_xit)
|
||||||
|
w1_yi := int(expand * w1_yit)
|
||||||
|
w2_xi := int(expand * w2_xit)
|
||||||
|
w2_yi := int(expand * w2_yit)
|
||||||
|
|
||||||
|
for y := boundsTL.Y; y <= boundsBR.Y; y++ {
|
||||||
|
w0 := w0_y
|
||||||
|
w1 := w1_y
|
||||||
|
w2 := w2_y
|
||||||
|
for x := boundsTL.X; x <= boundsBR.X; x++ {
|
||||||
|
if w0 >= 0 && w1 >= 0 && w2 >= 0 {
|
||||||
|
fb.SetSafe(uint(x), uint(y), color)
|
||||||
|
// w0a := w0 * invarea
|
||||||
|
// w1a := w1 * invarea
|
||||||
|
// w2a := w2 * invarea
|
||||||
|
}
|
||||||
|
w0 += w0_xi
|
||||||
|
w1 += w1_xi
|
||||||
|
w2 += w2_xi
|
||||||
|
}
|
||||||
|
w0_y += w0_yi
|
||||||
|
w1_y += w1_yi
|
||||||
|
w2_y += w2_yi
|
||||||
|
}
|
||||||
|
}
|
||||||
|
Loading…
Reference in New Issue
Block a user