From 7480b394568f2b01d4482d2362d250351033c3cb Mon Sep 17 00:00:00 2001
From: Carlos Sanchez <randomouscrap98@aol.com>
Date: Sat, 27 Jul 2024 14:15:55 -0400
Subject: [PATCH] Seemingly working...

---
 tinyrender3/main.go   | 32 +++++++++++++++++---------------
 tinyrender3/render.go |  5 +++++
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/tinyrender3/main.go b/tinyrender3/main.go
index 3b57720..b2b4ce0 100644
--- a/tinyrender3/main.go
+++ b/tinyrender3/main.go
@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"log"
 	"math"
-	"math/rand"
+	//"math/rand"
 	"os"
 	"runtime/pprof" // For performance profiling (unnecessary)
 )
@@ -57,7 +57,7 @@ func main() {
 
 	log.Printf("Running render")
 
-	//light := Vec3f{0, 0, -1}
+	light := Vec3f{0, 0, -1}
 
 	// for range Repeat  {
 	// 	Triangle2(&fb, 0xFF0000, Vec2i{10, 70}, Vec2i{50, 160}, Vec2i{70, 80})
@@ -79,30 +79,32 @@ func main() {
 			for i := range 3 { // Triangles, bro
 				sc[i].X = (f[i].X + 1) * halfwidth
 				sc[i].Y = hi - (f[i].Y+1)*halfheight
-				sc[i].Z = f[i].Z // Pull Z value directly. This is fine, our z-buffer is currently float32
+				// NOTE: WE USE NEGATIVE Z BECAUSE IT'S SUPPOSED TO BE DISTANCE! AS-IS, CLOSER
+				// POINTS HAVE HIGHER Z VLAUES
+				sc[i].Z = -f[i].Z // Pull Z value directly. This is fine, our z-buffer is currently float32
 				minz = min(minz, sc[i].Z)
 				maxz = max(maxz, sc[i].Z)
 			}
 			// TESTING
 			zch := float32(*zcuthigh)
 			zcl := float32(*zcutlow)
-			if sc[0].Z > zch || sc[1].Z > zch || sc[2].Z > zch ||
-				sc[0].Z < zcl || sc[1].Z < zcl || sc[2].Z < zcl {
+			if -sc[0].Z > zch || -sc[1].Z > zch || -sc[2].Z > zch ||
+				-sc[0].Z < zcl || -sc[1].Z < zcl || -sc[2].Z < zcl {
 				continue
 			}
 			// To test something, we swap vertex 2 and 3
 			//sc[1], sc[2] = sc[2], sc[1]
 
-			//l1 := f[2].Sub(f[0])
-			//n := l1.CrossProduct(f[1].Sub(f[0]))
-			//n = n.Normalize()
-			//intensity := n.MultSimp(&light)
-			//if intensity > 0 {
-			//Triangle3(&fb, Col2Uint(byte(255*intensity), byte(255*intensity), byte(255*intensity)), sc[0], sc[1], sc[2])
-			Triangle3(&fb, uint(rand.Int()), sc[0], sc[1], sc[2])
-			//Triangle1(&fb, uint(rand.Int()), sc[0].ToVec2i(), sc[1].ToVec2i(), sc[2].ToVec2i())
-			//Triangle2(&fb, 0xFFFFFF, sc[0], sc[1], sc[2])
-			//}
+			l1 := f[2].Sub(f[0])
+			n := l1.CrossProduct(f[1].Sub(f[0]))
+			n = n.Normalize()
+			intensity := n.MultSimp(&light)
+			if intensity > 0 {
+				Triangle3(&fb, Col2Uint(byte(255*intensity), byte(255*intensity), byte(255*intensity)), sc[0], sc[1], sc[2])
+				//Triangle3(&fb, uint(rand.Int()), sc[0], sc[1], sc[2])
+				//Triangle1(&fb, uint(rand.Int()), sc[0].ToVec2i(), sc[1].ToVec2i(), sc[2].ToVec2i())
+				//Triangle2(&fb, 0xFFFFFF, sc[0], sc[1], sc[2])
+			}
 		}
 	}
 
diff --git a/tinyrender3/render.go b/tinyrender3/render.go
index 358690c..da22028 100644
--- a/tinyrender3/render.go
+++ b/tinyrender3/render.go
@@ -228,6 +228,11 @@ func Triangle3(fb *Framebuffer, color uint, v0f Vec3f, v1f Vec3f, v2f Vec3f) {
 	// Where to start our scanning
 	pstart := Vec2i{boundsTL.X, boundsTL.Y}
 	parea := EdgeFunctioni(v0, v1, v2)
+	// if parea < 0 {
+	// 	v1, v2 = v2, v1
+	// 	v1f, v2f = v2f, v1f
+	// 	parea = EdgeFunctioni(v0, v1, v2)
+	// }
 	invarea := 1 / float32(parea)
 	w0_y := EdgeFunctioni(v1, v2, pstart)
 	w1_y := EdgeFunctioni(v2, v0, pstart)