From 362ed0802cb311bb16c5ffb7a05775b9ba4dc3ad Mon Sep 17 00:00:00 2001
From: Carlos Sanchez <randomouscrap98@aol.com>
Date: Fri, 2 Aug 2024 00:56:29 -0400
Subject: [PATCH] Really dumb functions

---
 renderer1/hrend/math.go | 16 ++++++++++++++++
 renderer1/main.go       | 42 +++++++----------------------------------
 2 files changed, 23 insertions(+), 35 deletions(-)

diff --git a/renderer1/hrend/math.go b/renderer1/hrend/math.go
index 661899b..aaa433d 100644
--- a/renderer1/hrend/math.go
+++ b/renderer1/hrend/math.go
@@ -158,6 +158,22 @@ func (m *Mat44f) SetRotationZ(radang float32) {
 	m[2] = -m[4]
 }
 
+// TODO: need roll too
+func (m *Mat44f) SetModel(loc *Vec3f, yaw float32, pitch float32, scale float32, up *Vec3f) Vec3f {
+	// Use sphere equation to compute lookat vector through the two
+	// player-controled angles (pitch and yaw)
+	lookvec := Vec3f{
+		Z: float32(-math.Sin(float64(pitch)) * math.Cos(float64(yaw))),
+		X: float32(math.Sin(float64(pitch)) * math.Sin(float64(yaw))),
+		Y: float32(math.Cos(float64(pitch))),
+	}
+	m.SetLookAt(loc, loc.Add(&lookvec), up)
+	m.Set(0, 0, m.Get(0, 0)*scale)
+	m.Set(1, 1, m.Get(1, 1)*scale)
+	m.Set(2, 2, m.Get(2, 2)*scale)
+	return lookvec
+}
+
 // Note: use {0,1,0} for up for normal use
 func (m *Mat44f) SetLookAt(from *Vec3f, to *Vec3f, up *Vec3f) {
 	forward := from.Sub(to).Normalize()
diff --git a/renderer1/main.go b/renderer1/main.go
index f7f5d2c..369b7df 100644
--- a/renderer1/main.go
+++ b/renderer1/main.go
@@ -94,12 +94,6 @@ func main() {
 	rb := hrend.NewRenderbuffer(fb, Width, Height)
 	o, texture := loadDefault()
 
-	// light := hrend.Vec3f{
-	// 	X: 0,
-	// 	Y: 0,
-	// 	Z: -1,
-	// }
-
 	var thing hrend.Vec2i
 	log.Print(thing)
 
@@ -118,19 +112,11 @@ func main() {
 	camtrans := hrend.Vec3f{X: 0, Y: 0, Z: ZOffset}
 	camup := hrend.Vec3f{X: 0, Y: 1, Z: 0}
 
-	lookvec := hrend.Vec3f{X: 0, Y: 0, Z: -1}
 	// In our system, 0 degree yaw is facing -Z, into the scene
 	yaw := float32(0)
 	pitch := float32(math.Pi / 2) // Start looking flat
 
-	// in all three directions... I think??
-	//yrot := float32(0.0)
-
-	//var camrotation, camtrans hrend.Mat44f
-	//camrotation.SetIdentity()
-	//var camrotx, camroty, camrotz hrend.Mat44f
-	//var camrotx, camroty hrend.Mat44f
-	var camera hrend.Mat44f
+	var camera, moverot hrend.Mat44f
 
 	for !rl.WindowShouldClose() {
 
@@ -156,7 +142,7 @@ func main() {
 			newcamtrans.X -= Movement / Fps
 		}
 		// Moving forward moves in the negative z direction, since we FACE
-		// the -z axis
+		// the -z axis (the camera does anyway)
 		if rl.IsKeyDown(rl.KeyW) {
 			newcamtrans.Z -= Movement / Fps
 		}
@@ -170,23 +156,14 @@ func main() {
 			newcamtrans.Y -= Movement / Fps
 		}
 
-		lookvec.Z = float32(-math.Sin(float64(pitch)) * math.Cos(float64(yaw)))
-		lookvec.X = float32(math.Sin(float64(pitch)) * math.Sin(float64(yaw)))
-		lookvec.Y = float32(math.Cos(float64(pitch)))
-		//camrotx.SetRotationX(rotvec.X)
-		//camroty.SetRotationY(rotvec.Y)
-
-		//lookvec := camroty.Multiply(&camrotx).MultiplyPoint3(baselook)
+		// translate the new camera movement based on the yaw
+		moverot.SetRotationY(-yaw)
+		newcamtrans = moverot.MultiplyPoint3(newcamtrans)
 		camtrans = *camtrans.Add(&newcamtrans)
 
-		//camrotz.SetRotationZ(zrot)
-		//camrotation = *camrotation.Multiply(
-		// This might (thought not currently)
-		//camtrans.SetTranslation(xofs, yofs, zofs)
+		// The camera is really just a model
+		lookvec := camera.SetModel(&camtrans, yaw, pitch, 1.0, &camup)
 
-		camera.SetLookAt(&camtrans, camtrans.Add(&lookvec), &camup)
-
-		//screenmat := camrotx.Multiply(&camroty).Multiply(&camrotz).Multiply(&camtrans).Inverse().Multiply(&projection)
 		screenmat := camera.Inverse().Multiply(&projection)
 		screenmat = screenmat.Multiply(&viewport)
 
@@ -195,19 +172,15 @@ func main() {
 			fb.Data[i].G = 0
 			fb.Data[i].B = 0
 		}
-		//rl.ImageDrawRectangle(fb.Image, 0, 0, Width, Height, rl.Black)
-		//rl.ImageClearBackground(fb.Image, rl.Black)
 
 		var sc [3]hrend.Vertex
 		rb.ResetZBuffer()
 		for _, f := range o.Faces {
 			// Precompute perspective for vertices to save time. Notice Z
 			// is not considered: is this orthographic projection? Yeah probably...
-			//var fpt [3]hrend.Vec3f
 			for i := range 3 { // Triangles, bro
 				sc[i] = f[i]
 				sc[i].Pos = screenmat.MultiplyPoint3(f[i].Pos)
-				//fpt[i] = worldToCamera.MultiplyPoint3(f[i].Pos)
 			}
 
 			l1 := f[2].Pos.Sub(&f[0].Pos)
@@ -217,7 +190,6 @@ func main() {
 			if intensity < 0 {
 				intensity = 0
 			}
-			//intensity := float32(1.0)
 			hrend.TriangleTextured(&rb, texture, intensity, sc[0], sc[1], sc[2])
 			//hrend.TriangleFlat(&rb, hrend.Col2Uint(byte(255*intensity), byte(255*intensity), byte(255*intensity)), sc[0].Pos, sc[1].Pos, sc[2].Pos)
 		}