initial upload - working prototype

this prototype works with xbox controller, typing in the terminal window is working but nothing more, no backspace yet.

2d-engine.c

@@ -0,0 +1,51 @@
+#include "2d-engine.h"
+
+/* detect if a point is in a convex polygon:
+ * 1 = true  //  0 = false
+ * IMPORTANT: if the point is on an edge,
+ * 				return true*/
+int pointInConvexPoly (struct vec2 point, struct poly *poly){
+	/* method: calculate determinant for each edge
+	 * to know if the point is on the left or right side.
+	 * if the point is on the same side of all edges then
+	 * it is in the poly */
+
+	long det;
+	/* edge [AB] */
+	struct vec2 vertex_A;
+	struct vec2 vertex_B;
+	char sign;
+
+	/* last edge (last vertex to first vertex) */
+	vertex_A = poly->vertex_array[poly->vertex_len -1];
+	vertex_B = poly->vertex_array[0];
+
+	det = (point.y - vertex_A.y)*(vertex_B.x - vertex_A.x)
+		- (point.x - vertex_A.x)*(vertex_B.y - vertex_A.y);
+
+	if( det == 0 )
+		/* if the first det is null, we
+		 * must look for the sign of the second det */
+		sign = 0;
+	else
+	/* all det must have the same sign than the first det */
+	sign = (det > 0) * 2 -1;
+
+	for (int i = 1; i < poly->vertex_len; i++) {
+		vertex_A = poly->vertex_array[i-1];
+		vertex_B = poly->vertex_array[i];
+
+		det = (point.y - vertex_A.y)*(vertex_B.x - vertex_A.x)
+			- (point.x - vertex_A.x)*(vertex_B.y - vertex_A.y);
+
+		if (sign == 0)
+			/* if the first det was zero
+			 * get the sign of all det */
+			sign = (det > 0) * 2 -1;
+		else
+			/* if different sign */
+			if ((det * sign) < 0)
+				return 0;
+	}
+	return 1;
+}

2d-engine.h

@@ -0,0 +1,16 @@
+#ifndef TWODENGINE_H
+#define TWODENGINE_H
+
+struct vec2 {
+	char x;
+	char y;
+};
+
+struct poly {
+	char vertex_len;
+	struct vec2 *vertex_array;
+};
+
+int pointInConvexPoly (struct vec2 point, struct poly *poly);
+
+#endif

Makefile

@@ -0,0 +1,22 @@
+#########################
+# customise these
+CFILES := main.c input.c config.c graphics.c 2d-engine.c free-selection-keyboard.c
+PROG := prog
+CFLAGS := -Wall -Wextra -g
+LDFLAGS := -lSDL2
+########################
+
+# -MMD generates dependencies while compiling
+CFLAGS += -MMD
+CC := gcc
+
+OBJFILES := $(CFILES:.c=.o)
+DEPFILES := $(CFILES:.c=.d)
+
+$(PROG) : $(OBJFILES)
+	$(LINK.o) $(LDFLAGS) -o $@ $^
+
+clean :
+	rm -f $(PROG) $(OBJFILES) $(DEPFILES)
+
+-include $(DEPFILES)

config.h

@@ -0,0 +1,23 @@
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include <stdbool.h>
+
+#include "input.h"
+
+struct mapping {
+	struct btn btn_east;
+	struct btn btn_west;
+	struct btn btn_north;
+	struct btn btn_left;
+
+	struct btn left_bumper;
+	struct btn right_bumper;
+
+	struct joy joy_L;
+	struct joy joy_R;
+
+	bool rumble;
+};
+
+#endif