i think this is less code maybe but also it doesn't work

docs/res/sprites_metadata.c.txt

@@ -1,9 +0,0 @@
-sprite.c:
-
-struct Sprites
-
-collision_offset = {
-	quad1x1, quad1y1, quad1x2, quad1y2,
-	quad2x1, quad2y1, quad2x2, quad2y2,
-	quad3x1, quad3y1, quad3x2, quad3y2
-}

res/sprite_metadata.c

@@ -16,51 +16,59 @@ Sprite sprites_info[] = {
 
 		.bitmap_indexes[SI_UP] = 12, .bitmap_prop[SI_UP] = 0,
 			.collision_offset[SI_UP] = {
-				3,   8,   1,   7,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 3, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 3, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_DOWN] = 12, .bitmap_prop[SI_DOWN] = S_FLIPY,
 			.collision_offset[SI_DOWN] = {
-				3,   2,   1,   1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 3, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 3, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_LEFT] = 11, .bitmap_prop[SI_LEFT] = 0,
 			.collision_offset[SI_LEFT] = {
-				8,   3,   7,   1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 3},
+				.itr = { .x = 1, .y = 3},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_RIGHT] = 11, .bitmap_prop[SI_RIGHT] = S_FLIPX,
 			.collision_offset[SI_RIGHT] = {
-				2,   3,   1,   1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 3},
+				.itr = { .x = 1, .y = 3},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_UP_RIGHT] = 13, .bitmap_prop[SI_UP_RIGHT] = 0,
 			.collision_offset[SI_UP_RIGHT] = {
-				2,   8,   1,   7,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 7, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 7, .y = 2},
+				.ibr = { .x = 1, .y = 2},
 			},
 		.bitmap_indexes[SI_UP_LEFT] = 13, .bitmap_prop[SI_UP_LEFT] = S_FLIPX,
 			.collision_offset[SI_UP_LEFT] = {
-				8,   8,   7,   7,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 2, .y = 8},
+				.ibl = { .x = 8, .y = 2},
+				.ibr = { .x = 2, .y = 2},
 			},
 		.bitmap_indexes[SI_DOWN_LEFT] = 13, .bitmap_prop[SI_DOWN_LEFT] = S_FLIPX | S_FLIPY,
 			.collision_offset[SI_DOWN_LEFT] = {
-				8,   2,   7,   1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 7},
+				.itr = { .x = 2, .y = 7},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 2, .y = 1},
 			},
 		.bitmap_indexes[SI_DOWN_RIGHT] = 13, .bitmap_prop[SI_DOWN_RIGHT] = S_FLIPY,
 			.collision_offset[SI_DOWN_RIGHT] = {
-				2,   2,   1,   1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 7, .y = 7},
+				.itr = { .x = 1, .y = 7},
+				.ibl = { .x = 7, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			}
 	},
 	{
@@ -76,51 +84,59 @@ Sprite sprites_info[] = {
 
 		.bitmap_indexes[SI_UP] = 14, .bitmap_prop[SI_UP] = 0,
 			.collision_offset[SI_UP] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_DOWN] = 15, .bitmap_prop[SI_DOWN] = 0,
 			.collision_offset[SI_DOWN] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_LEFT] = 14, .bitmap_prop[SI_LEFT] = 0,
 			.collision_offset[SI_LEFT] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_RIGHT] = 14, .bitmap_prop[SI_RIGHT] = S_FLIPX,
 			.collision_offset[SI_RIGHT] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_UP_RIGHT] = 14, .bitmap_prop[SI_UP_RIGHT] = 0,
 			.collision_offset[SI_UP_RIGHT] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_UP_LEFT] = 14, .bitmap_prop[SI_UP_LEFT] = S_FLIPX,
 			.collision_offset[SI_UP_LEFT] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_DOWN_LEFT] = 15, .bitmap_prop[SI_DOWN_LEFT] = 0,
 			.collision_offset[SI_DOWN_LEFT] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_DOWN_RIGHT] = 15, .bitmap_prop[SI_DOWN_RIGHT] = S_FLIPX,
 			.collision_offset[SI_DOWN_RIGHT] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			}
 	},
 	{
@@ -136,51 +152,59 @@ Sprite sprites_info[] = {
 
 		.bitmap_indexes[SI_UP] = 25, .bitmap_prop[SI_UP] = 0,
 			.collision_offset[SI_UP] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_DOWN] = 22, .bitmap_prop[SI_DOWN] = 0,
 			.collision_offset[SI_DOWN] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_LEFT] = 21, .bitmap_prop[SI_LEFT] = 0,
 			.collision_offset[SI_LEFT] = {
-				8,5, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 5},
+				.itr = { .x = 1, .y = 5},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_RIGHT] = 21, .bitmap_prop[SI_RIGHT] = S_FLIPX,
 			.collision_offset[SI_RIGHT] = {
-				8,5, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 5},
+				.itr = { .x = 1, .y = 5},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_UP_RIGHT] = 23, .bitmap_prop[SI_UP_RIGHT] = 0,
 			.collision_offset[SI_UP_RIGHT] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_UP_LEFT] = 23, .bitmap_prop[SI_UP_LEFT] = S_FLIPX,
 			.collision_offset[SI_UP_LEFT] = {
-				8,8, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 8},
+				.itr = { .x = 1, .y = 8},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_DOWN_LEFT] = 24, .bitmap_prop[SI_DOWN_LEFT] = S_FLIPX,
 			.collision_offset[SI_DOWN_LEFT] = {
-				8,7, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 7},
+				.itr = { .x = 1, .y = 7},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			},
 		.bitmap_indexes[SI_DOWN_RIGHT] = 24, .bitmap_prop[SI_DOWN_RIGHT] = 0,
 			.collision_offset[SI_DOWN_RIGHT] = {
-				8,7, 1,1,
-				255, 255, 255, 255,
-				255, 255, 255, 255
+				.itl = { .x = 8, .y = 7},
+				.itr = { .x = 1, .y = 7},
+				.ibl = { .x = 8, .y = 1},
+				.ibr = { .x = 1, .y = 1},
 			}
 	}
 };

src/constants.h

@@ -4,15 +4,15 @@
 #define MAX_PLAYER_COUNT 1
 
 #define GRAV_ACC 1
-#define TERM_VELY 2
+#define TERM_VELY 3
 #define TERM_VELX 2
-#define TERM_VELY_DIVISOR 5
+#define TERM_VELY_DIVISOR 3
 #define TERM_VELX_DIVISOR 3
 
 #define JUMP_VEL 4
 #define JUMP_TIMEOUT_FRAMES 18
 
-#define DASH_VELL 4
+#define DASH_VELL 7
 // mfw when pythagoras irl :scream_cat:
 #define DASH_VELD 5
 #define DASH_TIMEOUT_FRAMES 30

src/main.c

@@ -12,7 +12,7 @@
 #include "./sprite.h"
 #include "./vec.h"
 
-#define NO_SCREEN_SPRITES 6
+#define NO_SCREEN_SPRITES 3
 
 void init_gfx()
 {
@@ -36,9 +36,8 @@ void main(void)
 
 	memcpy(&(screen_sprites[0]), &(sprites_info[2]), sizeof(Sprite));
 	memcpy(&(screen_sprites[1]), &(sprites_info[1]), sizeof(Sprite));
-	for (i = 2; i < NO_SCREEN_SPRITES; i++) memcpy(&(screen_sprites[i]), &(sprites_info[0]), sizeof(Sprite));
-
-	screen_sprites[4].has_joypad = 1;
+	memcpy(&(screen_sprites[2]), &(sprites_info[0]), sizeof(Sprite));
+	screen_sprites[0].has_joypad = 1;
 
 	for (i = 0; i < NO_SCREEN_SPRITES; i++) {
 		screen_sprites[i].bitmap_index_prev = -1;

src/sprite.c

@@ -1,15 +1,31 @@
 #include <gb/gb.h>
 #include <stdlib.h>
-#include <stdio.h>
 #include "./vec.h"
 #include "./constants.h"
 #include "./flags.h"
 #include "./map.h"
 
-
-#define LYO 8
 #define GET_TILE_INDEX_BY_COORD(x, y)	((((y) / PIXELS_PER_TILE) * 20) + ((x) / PIXELS_PER_TILE))
 
+#define GET_SPRITE_CORNERS(sprite, sc) \
+	sc.itl.x = sprite->pos.x - sprite->collision_offset[sprite->bitmap_index].itl.x; \
+	sc.itl.y = sprite->pos.y - sprite->collision_offset[sprite->bitmap_index].itl.y - 8; \
+	sc.itr.x = sprite->pos.x - sprite->collision_offset[sprite->bitmap_index].itr.x; \
+	sc.itr.y = sprite->pos.y - sprite->collision_offset[sprite->bitmap_index].itr.y - 8; \
+	sc.ibl.x = sprite->pos.x - sprite->collision_offset[sprite->bitmap_index].ibl.x; \
+	sc.ibl.y = sprite->pos.y - sprite->collision_offset[sprite->bitmap_index].ibl.y - 8; \
+	sc.ibr.x = sprite->pos.x - sprite->collision_offset[sprite->bitmap_index].ibr.x; \
+	sc.ibr.y = sprite->pos.y - sprite->collision_offset[sprite->bitmap_index].ibr.y - 8;
+
+
+typedef struct SpriteCorners {
+	UVec itl;
+	UVec itr;
+	UVec ibl;
+	UVec ibr;
+} SpriteCorners;
+
+
 typedef struct Sprites {
 	int gb_sprite_index;
 	int frames_since_last_dash;
@@ -21,13 +37,14 @@ typedef struct Sprites {
 	int has_diag_sprites;
 	int has_joypad;
 	char name[20];
-	int collision_offset[8][12];
+	SpriteCorners collision_offset[8];
 	UVec pos;
 	Vec vel;
 	Vec acc;
 } Sprite;
 
 
+int get_tile_index_by_coord(unsigned int x, unsigned int y);
 void sprite_iter_frame(Sprite *sprite, Map *map, int joypad, unsigned int *fc);
 void sprite_draw_to_screen(Sprite *sprite);
 void sprite_update_bitmap(Sprite *sprite);
@@ -36,10 +53,16 @@ void sprite_update_bitmap(Sprite *sprite);
 // update a sprite for stuff that changes every frame
 void sprite_iter_frame(Sprite *sprite, Map *map, int joypad, unsigned int *fc)
 {
-	unsigned int colx, coly;
-	UVec original_position;
+	SpriteCorners sc;
+	int c, collision_check_steps, sprite_internal_collision,
+	    absvelx = abs(sprite->vel.x), absvely = abs(sprite->vel.y);
+	int b_right = joypad & J_RIGHT, b_left = joypad & J_LEFT, b_up = joypad & J_UP,
+	    b_down = joypad & J_DOWN, b_a = joypad & J_A, b_b = joypad & J_B;
+	int tl, tr, bl, br, lt, lb, rt, rb;
 
 	// target displacement is sprite->vel but may collide, giving actual displacment
+	Vec displacement = {.x = 0, .y = 0};
+	UVec original_position;
 
 	if (sprite->frames_since_last_jump <= JUMP_TIMEOUT_FRAMES) sprite->frames_since_last_jump++;
 	if (sprite->frames_since_last_dash <= DASH_TIMEOUT_FRAMES) sprite->frames_since_last_dash++;
@@ -50,107 +73,119 @@ void sprite_iter_frame(Sprite *sprite, Map *map, int joypad, unsigned int *fc)
 	}
 
 	// player move left/right
-	if ((joypad & J_RIGHT) && (sprite->vel.x < TERM_VELX)) sprite->acc.x = 1;
-	else if ((joypad & J_LEFT) && (sprite->vel.x > -TERM_VELX)) sprite->acc.x = -1;
-	else sprite->acc.x = -sprite->vel.x/abs(sprite->vel.x);
+	if ((joypad & b_right) && (sprite->vel.x < TERM_VELX)) sprite->acc.x = 1;
+	else if ((joypad & b_left) && (sprite->vel.x > -TERM_VELX)) sprite->acc.x = -1;
+	else sprite->acc.x = -sprite->vel.x/absvelx;
 	sprite->vel.x += sprite->acc.x;
 
 	// player dash
-	if ((joypad & J_B) && (sprite->frames_since_last_dash > DASH_TIMEOUT_FRAMES)) {
+	if (b_b && (sprite->frames_since_last_dash > DASH_TIMEOUT_FRAMES)) {
 		int frames_since_last_dash_copy = sprite->frames_since_last_dash;
 		sprite->frames_since_last_dash = 0;
 
-		if ((joypad & J_LEFT) && !(joypad & (J_UP | J_RIGHT | J_DOWN))) {
-			sprite->vel.x = -DASH_VELL;
-		} else if ((joypad & J_RIGHT) && !(joypad & (J_UP | J_LEFT | J_DOWN))) {
-			sprite->vel.x = DASH_VELL;
-		} else if ((joypad & J_UP) && !(joypad & (J_RIGHT | J_LEFT | J_DOWN))) {
-			sprite->vel.y = -DASH_VELL;
-		} else if ((joypad & J_DOWN) && !(joypad & (J_UP | J_LEFT | J_RIGHT))) {
-			sprite->vel.y = DASH_VELL;
-		} else if ((joypad & J_RIGHT) && (joypad & J_UP)) {
-			sprite->vel.x = DASH_VELD;
-			sprite->vel.y = -DASH_VELD;
-		} else if ((joypad & J_LEFT) && (joypad & J_UP)) {
-			sprite->vel.x = -DASH_VELD;
-			sprite->vel.y = -DASH_VELD;
-		} else if ((joypad & J_LEFT) && (joypad & J_DOWN)) {
-			sprite->vel.x = -DASH_VELD;
-			sprite->vel.y = DASH_VELD;
-		} else if ((joypad & J_RIGHT) && (joypad & J_DOWN)) {
-			sprite->vel.x = DASH_VELD;
-			sprite->vel.y = DASH_VELD;
-		} else {
-			// if player doesn't hold the right buttons to dash, don't dash and set the
-			// frames_since_last_dash counter back to what it was before
-			sprite->frames_since_last_dash = frames_since_last_dash_copy;
+		if (b_left) {
+			if (b_up) {
+				sprite->vel.x = -DASH_VELD;
+				sprite->vel.y = -DASH_VELD;
+			} else if (b_down) {
+				sprite->vel.x = -DASH_VELD;
+				sprite->vel.y = DASH_VELD;
+			} else {
+				sprite->vel.x = -DASH_VELL;
+			}
+		} else if (b_right) {
+			if (b_up) {
+				sprite->vel.x = DASH_VELD;
+				sprite->vel.y = -DASH_VELD;
+			} else if (b_down) {
+				sprite->vel.x = DASH_VELD;
+				sprite->vel.y = DASH_VELD;
+			} else {
+				sprite->vel.x = DASH_VELL;
+			}
 		}
+		else if (b_up) sprite->vel.y = -DASH_VELL;
+		else if (b_down) sprite->vel.y = DASH_VELL;
+		// if player doesn't hold the right buttons to dash, don't dash and set the
+		// frames_since_last_dash counter back to what it was before
+		else sprite->frames_since_last_dash = frames_since_last_dash_copy;
 	}
 
 	// slow down sprite in kind of realistic way
 	// (in real life i think it's drag is proportional to sprite->vel square but not
 	// sure if that is worth the compute yet cause everythign else is shit)
-	if (sprite->vel.y > TERM_VELY) sprite->vel.y   =  TERM_VELY;
-	if (sprite->vel.y < -TERM_VELY) sprite->vel.y += (abs(sprite->vel.y)-TERM_VELY)/TERM_VELY_DIVISOR;
+	if (sprite->vel.y > TERM_VELY) sprite->vel.y  -= (absvely-TERM_VELY)/TERM_VELY_DIVISOR;
+	if (sprite->vel.y < -TERM_VELY) sprite->vel.y += (absvely-TERM_VELY)/TERM_VELY_DIVISOR;
+	if (sprite->vel.x > TERM_VELX) sprite->vel.x  -= (absvelx-TERM_VELX)/TERM_VELX_DIVISOR;
+	if (sprite->vel.x < -TERM_VELX) sprite->vel.x += (absvelx-TERM_VELX)/TERM_VELX_DIVISOR;
+	
+	absvelx = abs(sprite->vel.x);
+	absvely = abs(sprite->vel.y);
 
-	int *offsets = sprite->collision_offset[sprite->bitmap_index];
-	// jump if on platform
-	if ((joypad & J_A) && (sprite->frames_since_last_jump > JUMP_TIMEOUT_FRAMES)) {
-		coly = map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[0], sprite->pos.y - offsets[3]-LYO+1)];
-		if (!coly) coly += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[2], sprite->pos.y - offsets[3]-LYO+1)];
-		if(coly) {
-			sprite->vel.y = -JUMP_VEL;
-			sprite->frames_since_last_jump = 0;
+	// if sprite not moving, no more logic needs to be done --- right?
+	if ((absvelx == 0) && (absvely == 0)) return;
+
+	GET_SPRITE_CORNERS(sprite, sc);
+
+	// don't let player move in a direction which they are already touching something
+	if (sprite->vel.y > 0) {
+		br = map->data[GET_TILE_INDEX_BY_COORD(sc.ibl.x, sc.ibl.y+1)];
+		bl = map->data[GET_TILE_INDEX_BY_COORD(sc.ibr.x, sc.ibr.y+1)];
+
+		if (bl | br) {
+			sprite->vel.y = 0;
+			// player jump
+			if (b_a && (sprite->frames_since_last_jump > JUMP_TIMEOUT_FRAMES)) {
+				sprite->vel.y = -JUMP_VEL;
+				sprite->frames_since_last_jump = 0;
+			}
 		}
+	} else if (sprite->vel.y < 0) {
+		tl = map->data[GET_TILE_INDEX_BY_COORD(sc.itl.x, sc.itl.y-1)];
+		tr = map->data[GET_TILE_INDEX_BY_COORD(sc.itr.x, sc.itr.y-1)];
+		if (tl | tr) sprite->vel.y = 0;
 	}
 
+	if (sprite->vel.x > 0) {
+		rt = map->data[GET_TILE_INDEX_BY_COORD(sc.itr.x+1, sc.itr.y)];
+		rb = map->data[GET_TILE_INDEX_BY_COORD(sc.ibr.x+1, sc.ibr.y)];
+		if (rt | rb) sprite->vel.x = 0;
+	} else if (sprite->vel.x < 0) {
+		lt = map->data[GET_TILE_INDEX_BY_COORD(sc.itl.x-1, sc.itl.y)];
+		lb = map->data[GET_TILE_INDEX_BY_COORD(sc.ibl.x-1, sc.ibl.y)];
+		if (lt | lb) sprite->vel.x = 0;
+	}
+
+	absvelx = abs(sprite->vel.x);
+	absvely = abs(sprite->vel.y);
+
+	collision_check_steps =  (absvelx > absvely) ? absvelx : absvely;
+
 	original_position.x = sprite->pos.x;
 	original_position.y = sprite->pos.y;
 	// check if following the path by the velocity will lead to a collision
+	for (int step = collision_check_steps; step >= 0; step--) {
+		sprite->pos.x = original_position.x + ((step * sprite->vel.x)/collision_check_steps);
+		sprite->pos.y = original_position.y + ((step * sprite->vel.y)/collision_check_steps);
 
-	// if no velocity component, pretend sprite has already collided
-	colx = sprite->vel.x == 0;
-	coly = sprite->vel.y == 0;
-
-	//for (int step = collision_check_steps; step >= 0; step--) {
-	if(sprite->vel.y != 0){
-		sprite->pos.y = original_position.y + sprite->vel.y;
-
-		if (sprite->vel.y < 0) {
-			coly += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[0], sprite->pos.y - offsets[1]-LYO)];
-			if (!coly) coly += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[2], sprite->pos.y - offsets[1]-LYO)];
-		} else if (sprite->vel.y > 0) {
-			coly += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[0], sprite->pos.y - offsets[3]-LYO)];
-			if (!coly) coly += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[2], sprite->pos.y - offsets[3]-LYO)];
-		}
-		
-		if (coly) sprite->pos.y = original_position.y;
+		sprite_internal_collision = 0;
+		if (map->data[GET_TILE_INDEX_BY_COORD(sc.itl.x, sc.itl.y)]) sprite_internal_collision++;
+		if (map->data[GET_TILE_INDEX_BY_COORD(sc.itr.x, sc.itr.y)]) sprite_internal_collision++;
+		if (map->data[GET_TILE_INDEX_BY_COORD(sc.ibl.x, sc.ibl.y)]) sprite_internal_collision++;
+		if (map->data[GET_TILE_INDEX_BY_COORD(sc.ibr.x, sc.ibr.y)]) sprite_internal_collision++;
+		if (sprite_internal_collision == 0) break;
 	}
 
-	if(sprite->vel.x != 0) {
-		sprite->pos.x = original_position.x + sprite->vel.x;
-
-		if (sprite->vel.x < 0) {
-			colx += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[0], sprite->pos.y - offsets[1]-LYO)];
-			if(!colx) colx += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[0], sprite->pos.y - offsets[3]-LYO)];
-		} else if (sprite->vel.x > 0) {
-			colx += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[2], sprite->pos.y - offsets[1]-LYO)];
-			if(!colx) colx += map->data[GET_TILE_INDEX_BY_COORD(sprite->pos.x - offsets[2], sprite->pos.y - offsets[3]-LYO)];
-		}
-
-		if (colx) sprite->pos.x = original_position.x;
-	}
-
-	sprite_update_bitmap(sprite);
 	sprite_draw_to_screen(sprite);
+	move_sprite(sprite->gb_sprite_index, sprite->pos.x, sprite->pos.y);
 }
 
+
+// set new sprite bitmap
 void sprite_update_bitmap(Sprite *sprite)
 {
-
 	sprite->bitmap_index_prev = sprite->bitmap_index;
-
-	     if ((sprite->vel.y > 0) && (sprite->vel.x > 0)) sprite->bitmap_index = SI_DOWN_RIGHT;
+	if ((sprite->vel.y > 0) && (sprite->vel.x > 0)) sprite->bitmap_index = SI_DOWN_RIGHT;
 	else if ((sprite->vel.y < 0) && (sprite->vel.x > 0)) sprite->bitmap_index = SI_UP_RIGHT;
 	else if ((sprite->vel.y > 0) && (sprite->vel.x < 0)) sprite->bitmap_index = SI_DOWN_LEFT;
 	else if ((sprite->vel.y < 0) && (sprite->vel.x < 0)) sprite->bitmap_index = SI_UP_LEFT;
@@ -163,11 +198,11 @@ void sprite_update_bitmap(Sprite *sprite)
 
 void sprite_draw_to_screen(Sprite *sprite)
 {
-	int bmi = sprite->bitmap_index;
-
-	if (sprite->bitmap_index_prev != bmi) {
-		set_sprite_tile(sprite->gb_sprite_index, sprite->bitmap_indexes[bmi]);
-		set_sprite_prop(sprite->gb_sprite_index, sprite->bitmap_prop[bmi]);
+	// only set sprite if sprite to be used has changed
+	sprite_update_bitmap(sprite);
+	if (sprite->bitmap_index_prev != sprite->bitmap_index) {
+		set_sprite_tile(sprite->gb_sprite_index, sprite->bitmap_indexes[sprite->bitmap_index]);
+		set_sprite_prop(sprite->gb_sprite_index, sprite->bitmap_prop[sprite->bitmap_index]);
 	}
 	move_sprite(sprite->gb_sprite_index, sprite->pos.x, sprite->pos.y);
 }

src/sprite.h

@@ -22,13 +22,15 @@ typedef struct Sprites {
 	int has_diag_sprites;
 	int has_joypad;
 	char name[20];
-	int collision_offset[8][12];
+	SpriteCorners collision_offset[8];
 	UVec pos;
 	Vec vel;
 	Vec acc;
 } Sprite;
 
 void sprite_iter_frame(Sprite *sprite, Map *map, int joypad, unsigned int *fc);
+unsigned int sprite_internal_collision(Map *map, Sprite *sprite);
+unsigned int sprite_collision(Map *map, Sprite *sprite);
 void sprite_draw_to_screen(Sprite *sprite);
 
 #endif