From abad63970f31855b1d7b5cb3bfefa64bf556b53b Mon Sep 17 00:00:00 2001
From: KikooDX <kikoodx@paranoici.org>
Date: Wed, 2 Mar 2022 23:32:07 +0100
Subject: [PATCH] draw line

---
 inc/lzy.h  | 34 ++++++++++++++++++++++++++++++++++
 src/main.c | 19 +++++++++++++++----
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/inc/lzy.h b/inc/lzy.h
index 516c073..57d1ee7 100644
--- a/inc/lzy.h
+++ b/inc/lzy.h
@@ -51,6 +51,7 @@ void LZY_DrawSetColor(uint8_t r, uint8_t g, uint8_t b);
 void LZY_DrawSetColorNone(void);
 int LZY_DrawClear(void);
 int LZY_DrawPoint(int x, int y);
+int LZY_DrawLine(int x0, int y0, int x1, int y1);
 int LZY_DrawRect(int x, int y, unsigned int w, unsigned int h);
 int LZY_DrawFillRect(int x, int y, unsigned int w, unsigned int h);
 int LZY_DrawTile(unsigned int id, int x, int y);
@@ -128,6 +129,39 @@ enum LZY_ScanCode {
 #define LZY_FIRST_CHR ' '
 #endif
 
+int LZY_DrawLine(int x0, int y0, int x1, int y1) {
+	int dx, dy, sx, sy, err, e2;
+	int rc = 0;
+
+	dx = x1 - x0;
+	dx = (dx < 0) ? (-dx) : (dx);
+	dy = y1 - y0;
+	dy = (dy < 0) ? (dy) : (-dy);
+	sx = (x0 < x1) ? (1) : (-1);
+	sy = (y0 < y1) ? (1) : (-1);
+	err = dx + dy;
+
+	for (;;) {
+		if (LZY_DrawPoint(x0, y0))
+			rc = -1;
+
+		if (x0 == x1 && y0 == y1)
+			break;
+
+		e2 = 2 * err;
+		if (e2 >= dy) {
+			err += dy;
+			x0 += sx;
+		}
+		if (e2 <= dx) {
+			err += dx;
+			y0 += sy;
+		}
+	}
+
+	return rc;
+}
+
 #ifdef FXCG50
 #include <gint/cpu.h>
 #include <gint/display.h>
diff --git a/src/main.c b/src/main.c
index 452f9d4..4dc6607 100644
--- a/src/main.c
+++ b/src/main.c
@@ -27,16 +27,18 @@ int main(void) {
 	LZY_MusicPlay(music, 0);
 
 	do {
+		const int speed = 2;
+
 		/* update */
 		LZY_CycleEvents();
 		if (LZY_KeyDown(LZYK_LEFT))
-			x--;
+			x -= speed;
 		if (LZY_KeyDown(LZYK_RIGHT))
-			x++;
+			x += speed;
 		if (LZY_KeyDown(LZYK_UP))
-			y--;
+			y -= speed;
 		if (LZY_KeyDown(LZYK_DOWN))
-			y++;
+			y += speed;
 
 		/* draw */
 		LZY_DrawBegin();
@@ -58,6 +60,15 @@ int main(void) {
 }
 
 static void draw_player(int x, int y) {
+	const int cx = x + 8;
+	const int cy = y + 8;
+
 	if (LZY_DrawTile(14, x, y))
 		LZY_Log(LZY_GetError());
+
+	LZY_DrawSetColor(0x00, 0xff, 0xff);
+	LZY_DrawLine(0, 0, cx - 1, cy - 1);
+	LZY_DrawLine(395, 0, cx, cy - 1);
+	LZY_DrawLine(0, 223, cx - 1, cy);
+	LZY_DrawLine(395, 223, cx, cy);
 }