From 75f9f7fbb2e33064f6341b12b0ec99dc6af444f6 Mon Sep 17 00:00:00 2001
From: InventorXtreme <inventorxtreme@gmail.com>
Date: Mon, 4 Dec 2023 12:15:12 -0500
Subject: [PATCH] rendering tri, still need to cull when behind

---
 c3d.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 147 insertions(+), 11 deletions(-)

diff --git a/c3d.c b/c3d.c
index 086e220..2baff56 100644
--- a/c3d.c
+++ b/c3d.c
@@ -1,5 +1,6 @@
 #include <math.h>
 #include <stdio.h>
+#include <string.h>
 #include "raylib.h"
 
 const int RENDERWIDTH = 1920;
@@ -35,9 +36,72 @@ struct LocalCam {
     Vector3 angleVelocity;
     Vector3 angleAcceleration;
 };
-
 typedef struct LocalCam LocalCam;
 
+struct Tri {
+    Vector3 a;
+    Vector3 b;
+    Vector3 c;
+
+    Color color;
+};
+typedef struct Tri Tri;
+
+struct Tri2D{
+    Vector2 a;
+    Vector2 b;
+    Vector2 c;
+
+    Color color;
+};
+typedef struct Tri2D Tri2D;
+
+struct Zee {
+    int depth;
+    Tri2D * triangle;
+};
+typedef struct Zee Zee;
+
+struct TriArray {
+    int length;
+    Tri* arr;
+};
+typedef struct TriArray TriArray;
+
+struct Tri2DArray {
+    int length;
+    Tri2D* arr;
+};
+typedef struct Tri2DArray Tri2DArray;
+
+float Sign(Vector2 v1, Vector2 v2, Vector2 v3) {
+    return (v1.x - v3.x) * (v2.y - v3.y) - (v2.x - v3.x) * (v1.y - v3.y);
+}
+
+bool IsInTri(Tri2D tri, Vector2 p) {
+    float d1, d2, d3;
+    bool has_neg, has_pos;
+
+    d1 = Sign(p, tri.a, tri.b);
+    d2 = Sign(p, tri.b, tri.c);
+    d3 = Sign(p, tri.c, tri.a);
+
+    has_neg = (d1 < 0) || (d2 < 0) || (d3 < 0);
+    has_pos = (d1 > 0) || (d2 > 0) || (d3 > 0);
+
+    return !(has_neg && has_pos);
+}
+
+void TriArrayAppend(TriArray * tarr, Tri  t) {
+    tarr->arr[tarr->length] = t;
+    tarr->length = tarr->length + 1;
+}
+
+void Tri2DArrayAppend(Tri2DArray * tarr, Tri2D  t) {
+    tarr->arr[tarr->length] = t;
+    tarr->length = tarr->length + 1;
+}
+
 Vector3 Vector3Sum(Vector3 v1, Vector3 v2) {
     Vector3 retvec;
     retvec.x = v1.x + v2.x;
@@ -188,11 +252,31 @@ Vector3 TransformWithCam(Vector3 v, LocalCam * cam) {
     return returnvector;
 }
 
+Tri TriTransformWithCam(Tri *t, LocalCam * cam) {
+    Tri rettri;
+    rettri.a = TransformWithCam(t->a,cam);
+    rettri.b = TransformWithCam(t->b,cam);
+    rettri.c = TransformWithCam(t->c,cam);
+    
+    rettri.color = t->color;
+    return rettri;
+}
+
+Tri2D ConvertTriToTri2D(Tri* t){
+    Tri2D rettri2d;
+    rettri2d.a = Conv3Dto2D(t->a);
+    rettri2d.b = Conv3Dto2D(t->b);
+    rettri2d.c = Conv3Dto2D(t->c);
+
+    rettri2d.a = Conv2DCenteredToScreen(rettri2d.a);
+    rettri2d.b = Conv2DCenteredToScreen(rettri2d.b);
+    rettri2d.c = Conv2DCenteredToScreen(rettri2d.c);
+
+    rettri2d.color = t->color;
+    return rettri2d;
+}
 int main() {
     proj = HALFWIDTH / tan(half_fov);
-
-
-    
     
     SetConfigFlags(FLAG_WINDOW_UNDECORATED);
     InitWindow(SCREENWIDTH, SCREENHEIGHT, "raylib [core] example - basic window");
@@ -223,6 +307,23 @@ int main() {
     
     Vector3 point = (Vector3){0,0,-10};
 
+    Tri internaltriarray[50];
+    TriArray tarr;
+    tarr.arr = internaltriarray;
+    tarr.length = 0;
+    TriArrayAppend(&tarr,(Tri){(Vector3){0,0,-1000},(Vector3){0,800,-1000},(Vector3){800,800,-1000},WHITE});
+
+    Tri internaltransformedtriarray[50];
+    TriArray TransformedTris;
+    TransformedTris.arr = internaltransformedtriarray;
+    TransformedTris.length = 0;
+
+    Tri2D internaltri2darray[50];
+    Tri2DArray Tri2Darr;
+    Tri2Darr.length=0;
+    Tri2Darr.arr = internaltri2darray;
+
+    static Zee ZBuff[1920][1080] = {{(Zee){10000,NULL}}}; //FIXME: Stupid static makes the file 32 Megs because pog
     
     
     while (!WindowShouldClose()) {
@@ -230,16 +331,51 @@ int main() {
 	CtrlLocalCam(&camera,frametime);
 	LocalCamApplyVelo(&camera,frametime);
         BeginTextureMode(renderTexture);
-        ClearBackground(WHITE);
+        ClearBackground(BLACK);
         DrawText("Congrats! You created your first window!", 190, 200, 20,
                  BLACK);
-	Vector3 TransVector = TransformWithCam(point,&camera);
-	if (TransVector.z < 0) {
-	Vector2 MPos = Conv3Dto2D(TransVector);
-	Vector2 FinPos = Conv2DCenteredToScreen(MPos);
-	DrawCircleV(FinPos,100,BLACK);
+	/* Vector3 TransVector = TransformWithCam(point,&camera); */
+	/* if (TransVector.z < 0) { */
+	/* Vector2 MPos = Conv3Dto2D(TransVector); */
+	/* Vector2 FinPos = Conv2DCenteredToScreen(MPos); */
+	/* DrawCircleV(FinPos,100,BLACK); */
+	/* } */
+        /* EndTextureMode(); */
+
+	TransformedTris.length = 0;
+	Tri2Darr.length = 0;
+
+	for (int i = 0; i < tarr.length; i++) {
+	    TriArrayAppend(&TransformedTris,TriTransformWithCam(&tarr.arr[i],&camera));
 	}
-        EndTextureMode();
+
+	for(int i = 0; i < TransformedTris.length; i++) {
+	    Tri2DArrayAppend(&Tri2Darr,ConvertTriToTri2D(&TransformedTris.arr[i]));
+	}
+
+	memset(ZBuff,0,sizeof(ZBuff));
+	
+	for(int i = 0; i < Tri2Darr.length; i++) {
+	    for(int y = 0; y < RENDERHEIGHT; y++){
+		for(int x = 0; x< RENDERWIDTH; x++) {
+		    if (IsInTri(Tri2Darr.arr[i],(Vector2){x,y})) {
+			ZBuff[x][y].triangle = &Tri2Darr.arr[i];
+		    }
+		}
+	    }
+	}
+
+	for(int y = 0; y < RENDERHEIGHT; y++) {
+	    for(int x = 0; x < RENDERWIDTH; x++) {
+		if (ZBuff[x][y].triangle != NULL){
+		    DrawPixel(x,y,ZBuff[x][y].triangle->color);
+		}
+		
+	    }
+
+	}
+
+	EndTextureMode();
 
 	//Copytexture to main display :0