From c5daa136c111182bb57e7ac952e357c9b142a99a Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cdo@wip.sh>
Date: Sat, 28 Dec 2024 14:27:13 +0000
Subject: [PATCH] Use directional sprites for player

---
 app/main.c | 50 +++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 39 insertions(+), 11 deletions(-)

diff --git a/app/main.c b/app/main.c
index 73fa03b..5577506 100644
--- a/app/main.c
+++ b/app/main.c
@@ -29,15 +29,24 @@
 #define TSASSET "/tileset.png"
 #define TSCOLS 56
 
-#define PIASSET "/player/idle/down.png"
-#define PIWIDTH 48
-#define PIHEIGHT 64
-#define PIANIMLEN 8
+#define PIDLE_ASSET "/player/idle.png"
+#define PWIDTH 48
+#define PHEIGHT 64
+#define PANIMLEN 8
 
 #define WALKSPEED 72 // pixels per second
 
 #define BASEANIMPERIOD 200
 
+typedef enum {
+	SPRITE_DIR_DOWN = 0,
+	SPRITE_DIR_LEFT_DOWN = 1,
+	SPRITE_DIR_LEFT_UP = 2,
+	SPRITE_DIR_UP = 3,
+	SPRITE_DIR_RIGHT_UP = 4,
+	SPRITE_DIR_RIGHT_DOWN = 5,
+} sprite_dir_t;
+
 typedef struct {
 	bool left, right, up, down;
 } input_state_t;
@@ -49,7 +58,7 @@ typedef struct {
 static SDL_Window *window;
 static SDL_Renderer *renderer;
 static unsigned map[MAPWIDTH][MAPHEIGHT];
-static SDL_Texture *tstex, *pitex;
+static SDL_Texture *tstex, *pidle;
 static input_state_t input;
 
 static inline double mag(dvec_t v)
@@ -155,17 +164,18 @@ int main(int argc, char *argv[])
 	assert(NULL != tstex);
 
 	// Load player idle spritesheet
-	assert(strlen(argv[1]) + strlen(PIASSET) < MAX_PATH_LEN);
+	assert(strlen(argv[1]) + strlen(PIDLE_ASSET) < MAX_PATH_LEN);
 	strcpy(path, argv[1]);
-	strcat(path, PIASSET);
-	pitex = IMG_LoadTexture(renderer, path);
-	assert(NULL != pitex);
+	strcat(path, PIDLE_ASSET);
+	pidle = IMG_LoadTexture(renderer, path);
+	assert(NULL != pidle);
 
 	// Initialize view and player
 	dvec_t vpos = { 512, 0 };
-	SDL_Rect psrc = { .y = 0, .w = PIWIDTH, .h = PIHEIGHT };
-	SDL_Rect pdest = { .w = SCALE * PIWIDTH, .h = SCALE * PIHEIGHT };
+	SDL_Rect psrc = { .y = 0, .w = PWIDTH, .h = PHEIGHT };
+	SDL_Rect pdest = { .w = SCALE * PWIDTH, .h = SCALE * PHEIGHT };
 	dvec_t pvel = { 0, 0 }, ppos = { 640, 96 };
+	sprite_dir_t pdir = SPRITE_DIR_DOWN;
 
 	SDL_Event event;
 	uint64_t prevt = SDL_GetTicks64();
@@ -232,6 +242,23 @@ int main(int argc, char *argv[])
 			pvel.y *= WALKSPEED / pspeed;
 			ppos.x += (double)dt / 1000.0 * pvel.x;
 			ppos.y += (double)dt / 1000.0 * pvel.y;
+
+			// Update direction
+			if (pvel.y >= 0) {
+				if (pvel.x > 0)
+					pdir = SPRITE_DIR_RIGHT_DOWN;
+				else if (pvel.x < 0)
+					pdir = SPRITE_DIR_LEFT_DOWN;
+				else
+					pdir = SPRITE_DIR_DOWN;
+			} else if (pvel.y < 0) {
+				if (pvel.x > 0)
+					pdir = SPRITE_DIR_RIGHT_UP;
+				else if (pvel.x < 0)
+					pdir = SPRITE_DIR_LEFT_UP;
+				else
+					pdir = SPRITE_DIR_UP;
+			}
 		}
 
 		// Update view
@@ -277,6 +304,7 @@ int main(int argc, char *argv[])
 		// Draw player
 		const unsigned piframe = (t / BASEANIMPERIOD) % PANIMLEN;
 		psrc.x = PWIDTH * piframe;
+		psrc.y = PHEIGHT * pdir;
 		pdest.x = SCALE * (int)(ppos.x - vpos.x - PWIDTH / 2);
 		pdest.y = SCALE * (int)(ppos.y - vpos.y - PHEIGHT / 2);
 		SDL_RenderCopy(renderer, pidle, &psrc, &pdest);