From 9e26b69f7b821e2e6cb0029a13574aa219ec1c23 Mon Sep 17 00:00:00 2001
From: InventorXtreme <inventorxtreme@gmail.com>
Date: Thu, 28 Dec 2023 03:11:09 -0500
Subject: [PATCH] reaa

---
 Makefile |  4 ++--
 c3d.c    | 67 +++++++++++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 56 insertions(+), 15 deletions(-)

diff --git a/Makefile b/Makefile
index bdbe69a..5c74128 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 CC = gcc
-CFLAGS = -pg -g -O2
-LDFLAGS = -pg -g
+CFLAGS = -pg -g -O2 -Wall 
+LDFLAGS = -pg -g 
 LDLIBS = -lraylib -lm
 objects  = c3d.o
 
diff --git a/c3d.c b/c3d.c
index 5d74f1f..4b2927b 100644
--- a/c3d.c
+++ b/c3d.c
@@ -84,6 +84,8 @@ double Max(double a, double b){
     return a;
 }
 
+
+//sort triangle verts so that point A is the "highest" point (lowest y val) and point C is the "lowest" pont (highest y val)
 void Tri2DSortByY(Tri2D * t){
     Vector2 temp;
     if (t->a.y > t->b.y) {
@@ -104,7 +106,12 @@ void Tri2DSortByY(Tri2D * t){
 }
 
 //Draws triangle with a flat top. Note A and B must be the top points with C being the bottom "spike"
-void FillTopFlatZbuffer(Zee zee[][1080], Tri2D* t) {
+void FillTopFlatZbuffer(Zee zee[][1080], Tri2D* t, Tri2D * tp) {
+    if (t->b.x < t->a.x) {
+	Vector2 e = t->b;
+	t->b = t->a;
+	t->a = e;
+    }
     //Becasue we are trying to get the x values in terms of the y values, we need inverse slope
     float atocslopeinv = (t->c.x - t->a.x) / (t->c.y - t->a.y); //dif in x from start to end with a and c
     float btocslopinv = (t->c.x - t->b.x) / (t->c.y - t->b.y); //dif in x from start to end with b and c 
@@ -116,17 +123,24 @@ void FillTopFlatZbuffer(Zee zee[][1080], Tri2D* t) {
     for(int scanline=t->c.y; scanline >= t->a.y; scanline--){
 	if (0 <= scanline && scanline < RENDERHEIGHT){
 	    for (int i = Max(curx1,0); i < Min(curx2,RENDERWIDTH); i++) {
-		zee[i][scanline].triangle = t;
+		zee[i][scanline].triangle = tp;
 	    }
 	}
 	curx1 -= atocslopeinv; //subtract because we are working backwards (reason why we start with point c in slope equtn)
 	curx2 -= btocslopinv;
     }
 }
-
+void PrintTri2D(Tri2D t) {
+    printf("{(TRI2D) A: (%f, %f), B: (%f, %f), C:(%f,%f) }\n ",t.a.x,t.a.y,t.b.x, t.b.y, t.c.x, t.c.y); 
+}
 
 //Draws triangle with a flat bottomp. Note B and C must be the bottom points with A being the top "spike"
-void FillBottomFlatZbuffer(Zee zee[][1080], Tri2D* t) {
+void FillBottomFlatZbuffer(Zee zee[][1080], Tri2D* t, Tri2D * tp) {
+    if (t->c.x < t->b.x) {
+	Vector2 e = t->c;
+	t->c = t->b;
+	t->b = e;
+    }
     //Becasue we are trying to get the x values in terms of the y values, we need inverse slope
     float atobslopeinv = (t->b.x - t->a.x) / (t->b.y - t->a.y); //dif in x from start to end with a and c
     float atocslopeinv = (t->c.x - t->a.x) / (t->c.y - t->a.y); //dif in x from start to end with b and c 
@@ -138,7 +152,7 @@ void FillBottomFlatZbuffer(Zee zee[][1080], Tri2D* t) {
     for(int scanline=t->a.y; scanline < t->c.y; scanline++){
 	if (0 <= scanline && scanline < RENDERHEIGHT){
 	    for (int i = Max(curx1,0); i < Min(curx2,RENDERWIDTH); i++) {
-		zee[i][scanline].triangle = t;
+		zee[i][scanline].triangle = tp;
 	    }
 	}
 	curx1 += atobslopeinv;
@@ -147,16 +161,38 @@ void FillBottomFlatZbuffer(Zee zee[][1080], Tri2D* t) {
 
 }
 
-void DrawTriZuff(Zee zbuf[][1080], Tri2D t){
-    Tri2DSortByY(&t);
 
-    if (t.b.y == t.c.y) {
-	FillBottomFlatZbuffer(zbuf,&t);
+
+void DrawTriZuff(Zee zbuf[][1080], Tri2D * t){
+    Tri2DSortByY(t);
+
+    if (t->b.y == t->c.y) { // if bottom of triangle is flat
+	FillBottomFlatZbuffer(zbuf,t,t);
     }
-    else if (t.a.y == t.b.y) {
-	FillTopFlatZbuffer(zbuf,&t);
-    } else{ //funny split tri
+    else if (t->a.y == t->b.y) { //if top of triangle is flat
 	
+	FillTopFlatZbuffer(zbuf,t,t);
+
+    } else{ //funny split tri
+	Vector2 v4; //v4 is the vertex on the line between a and c. It is used to split the triangle into a top and bottom
+	v4.y = t->b.y;
+	float slope = (float)((t->c.x) - (t->a.x)) /((float)(t->c.y - t->a.y)); //get slope in run over rise becasue we need to find x
+	float changeiny = (float) (t->b.y - t->a.y);
+	float officalxpos = t->a.x + (slope*changeiny);
+	v4.x = officalxpos;
+	Tri2D bottomflattrires;
+	bottomflattrires.a = t->a;
+	bottomflattrires.b = t->b;
+	bottomflattrires.c = v4;
+	bottomflattrires.color = t->color;
+	Tri2D topflattrires;
+	topflattrires.a = t->b;
+	topflattrires.b = v4;
+	topflattrires.c = t->c;
+	topflattrires.color = t->color;
+
+	FillBottomFlatZbuffer(zbuf, &bottomflattrires, t);
+	FillTopFlatZbuffer(zbuf, &topflattrires, t);
     }
 
     
@@ -430,7 +466,10 @@ int main() {
     Tri2D fullscreentribottom = (Tri2D){ (Vector2){0,0}, (Vector2){0,1080}, (Vector2){1920,1080}, RED};
 
     
-    Tri2D blank = (Tri2D) { (Vector2){-10,-10},(Vector2){-10,-10}, (Vector2){-10,-10}};    
+    Tri2D blank = (Tri2D) { (Vector2){-10,-10},(Vector2){-10,-10}, (Vector2){-10,-10}};
+
+    Tri2D norm =  (Tri2D){ (Vector2){500,50},(Vector2){0,0},(Vector2){250,500},GREEN};
+    
     while (!WindowShouldClose()) {
 	float frametime = GetFrameTime();
 	CtrlLocalCam(&camera,frametime);
@@ -485,6 +524,8 @@ int main() {
 	//FillTopFlatZbuffer(ZBuff, &fullscreentritop);
 	//FillBottomFlatZbuffer(ZBuff, &fullscreentribottom);
 
+	DrawTriZuff(ZBuff, &norm);
+
 
 
 	int index = 0;