acho que tem sombras, porem tem que arrumar a ordem de renderizacao

2 files changed, 29 insertions, 13 deletions

diff --git a/donut.c b/donut.c
index 3862056..9355ed4 100644
--- a/donut.c
+++ b/donut.c
@@ -1,6 +1,9 @@
 #include "donut.h"
 #include <raylib.h>
 
+point3d light1 = {10, 10, 10};
+point3d light2 = {-10, -10, -10};
+point3d light3 = {-5, 0, -5};
 //center nao deve ter passado pela funcao map antes
 void draw_circle(point2d center, double radius){
 	double angle = 0;
@@ -10,10 +13,6 @@ void draw_circle(point2d center, double radius){
 		for(double i=0; i<2*PI; i+=0.01){
 			double r = radius;
 
-			//point3d tmpc = {center.x, center.y, 0};
-			//tmpc = rotate_x(tmpc, angle);
-			//center.x = tmpc.x; center.y = tmpc.y;
-
 			point2d aux = {r*cos(i), r*sin(i)};
 			aux.x += center.x; aux.y += center.y;
 
@@ -23,18 +22,33 @@ void draw_circle(point2d center, double radius){
 			tmp3 = rotate_x(tmp3, static_angle);
 			aux.x = tmp3.x; aux.y = tmp3.y;
 
-			//point3d tmp = {aux.x, aux.y, 0};
-			//tmp = rotate_y(tmp, angle);
-			//aux.x = tmp.x; aux.y = tmp.y;
+			// normal N = tmp3 - center
+			point3d cen = {center.x, center.y, 0};
+			cen = rotate_y(cen, angle);
+			cen = rotate_z(cen, static_angle);
+			cen = rotate_x(cen, static_angle);
 
-//			point3d tmp2 = {aux.x, aux.y, 0};
-//			tmp2 = rotate_x(tmp2, static_angle);
-//			aux.x = tmp2.x; aux.y = tmp2.y;
+			point3d N;
+			N.x = tmp3.x - cen.x;
+			N.y = tmp3.y - cen.y;
+			N.z = tmp3.z - cen.z;
+			
+			//(N ^ light)
+			double lv1 = N.x * light1.x + N.y * light1.y + N.z * light1.z;
+			double lv2 = N.x * light2.x + N.y * light2.y + N.z * light2.z;
+			double lv3 = N.x * light3.x + N.y * light3.y + N.z * light3.z;
+			lv2 = 0;
+			lv3 = 0;
+			double lv = MAX(MAX(lv1, lv2), lv3);
 
 			aux = map(aux);
-			DrawPixel(aux.x, aux.y, GREEN);
+			if(lv > 0){
+				int alp = 255 * lv / 5;
+				alp = (alp > 255 ? 255 : alp);
+				DrawPixel(aux.x, aux.y, (Color){0, 255, 0, alp});
+			}
 		}
-		angle += 0.005;
+		angle += 0.01;
 	}
 	static_angle += 0.05;
 }
diff --git a/donut.h b/donut.h
index 568ae80..e4e0519 100644
--- a/donut.h
+++ b/donut.h
@@ -5,6 +5,8 @@
 #include <stdio.h>
 #include <math.h>
 
+#define MAX(a,b) ((a)>(b)?(a):(b))
+
 #define SCREEN_WIDTH 640
 #define SCREEN_HEIGHT 640
 
@@ -26,4 +28,4 @@ point3d rotate_x(point3d p, double a);
 point3d rotate_y(point3d p, double a);
 point3d rotate_z(point3d p, double a);
 
-#endif
\ No newline at end of file
+#endif