Fix misc math bugs

This commit is contained in:
Pyrex 2024-02-27 21:49:20 -08:00
parent 5f522abcb5
commit c5c677320b
7 changed files with 91 additions and 28 deletions

View File

@ -9,29 +9,50 @@ bool game_collision_is_occlusive(sys_maptile tile) {
return false;
}
// c's modulus can produce a negative result. don't allow that!
#define modulus(x, mod) ((x) % (mod) + (mod)) % (mod)
#define round_down(x, incr) (x) - modulus(x, incr)
#define round_up(x, incr) round_down((x) + (incr) - 1, incr)
bool game_collision_can_move(game_bbox body, sys_i32 dx, sys_i32 dy) {
// First: place the body in space.
// Align its top-left corner to the pixel boundary
sys_i32 x = body.x + dx;
sys_i32 y = body.y + dy;
// the player can never leave the map
if (x < 0) { return false; }
if (y < 0) { return false; }
if (x + body.w > map_game_map.width * TILE_SZ_MICROPIXEL) {
return false;
}
if (y + body.h > map_game_map.height * TILE_SZ_MICROPIXEL) {
return false;
}
// this is extremely similar to the logic in move_to_contact
// but has different rounding behavior
// (because a body at a fractional position must not actually collide
// with fractional pixels)
sys_i32 body_x0 = round_down(x, PIXEL_SZ_MICROPIXEL);
sys_i32 body_y0 = round_down(y, PIXEL_SZ_MICROPIXEL);
sys_i32 body_x1 = body_x0 + body.w;
sys_i32 body_y1 = body_y0 + body.h;
sys_i32 tile_x0 = round_down(body_x0, TILE_SZ_MICROPIXEL);
sys_i32 tile_y0 = round_down(body_y0, TILE_SZ_MICROPIXEL);
sys_i32 tile_x1 = round_up(body_x1, TILE_SZ_MICROPIXEL);
sys_i32 tile_y1 = round_up(body_y1, TILE_SZ_MICROPIXEL);
// now convert to tile coords instead of pixels
tile_x0 /= TILE_SZ_MICROPIXEL;
tile_y0 /= TILE_SZ_MICROPIXEL;
tile_x1 /= TILE_SZ_MICROPIXEL;
tile_y1 /= TILE_SZ_MICROPIXEL;
for (sys_i32 y = tile_y0; y < tile_y1; y++) {
for (sys_i32 x = tile_x0; x < tile_x1; x++) {
bool invalid;
sys_maptile tile = sys_map_get(map_game_map, x, y, &invalid);
if (invalid || game_collision_is_occlusive(tile)) {
return false;
}
}
}
// TODO: Collide with blocks
// If two collides with a block, check if one collides with it.
// The collision only matters if one doesn't.
return true;
}
#define round_down(x, incr) (x) - (x) % (incr)
#define round_up(x, incr) round_down((x) + (incr) - 1, incr)
game_collision game_collision_move_to_contact(
game_bbox* body, sys_i32 total_dx, sys_i32 total_dy
) {

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@ -5,6 +5,7 @@
#include "sys/sys.h"
#define TILE_SZ_MICROPIXEL 0x800
#define PIXEL_SZ_MICROPIXEL 0x100
typedef struct {
sys_i32 x;
@ -24,4 +25,4 @@ bool game_collision_is_occlusive(sys_maptile tile);
bool game_collision_can_move(game_bbox body, sys_i32 dx, sys_i32 dy);
game_collision game_collision_move_to_contact(game_bbox* body, sys_i32 x, sys_i32 y);
#endif
#endif // GAME_COLLISION_H

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@ -5,12 +5,15 @@
#include "game.h"
#include "sys/sys.h"
#define GAME_PLAYER_ORIGIN_X 4
#define GAME_PLAYER_ORIGIN_Y 4
game_bbox game_player_bbox = {
.x=0x9000,
// .y=0x5800,
.y=0x0000,
.w=0x1000,
.h=0x1000,
.w=0x0800,
.h=0x0c00,
};
bool game_player_grounded = false;
sys_i32 game_player_jump_frames = 0;
@ -44,7 +47,9 @@ void game_player_update() {
if (collision.collided_x) { game_player_dx = 0; }
if (collision.collided_y) { game_player_dy = 0; }
game_player_grounded = !game_collision_can_move(game_player_bbox, 0, 1);
game_player_grounded = !game_collision_can_move(
game_player_bbox, 0, PIXEL_SZ_MICROPIXEL
);
{
sys_i32 fric_numerator = game_player_grounded ? 0x70 : 0x7f;
@ -63,8 +68,11 @@ void game_player_update() {
// allow this if grounded or if it's not a change of direction
if (
/*
game_player_grounded ||
(sys_sgn_i32(wanted_dx) == sys_sgn_i32(game_player_dx))
*/
true
) {
game_player_dx = wanted_dx;
} else {
@ -74,19 +82,20 @@ void game_player_update() {
}
if (game_player_grounded || game_player_coyote_frames > 0) {
if (sys_btn(DEVICE_BUTTON_U)) {
if (sys_btnp(DEVICE_BUTTON_U, false)) {
game_player_dy = -0x300;
game_player_jump_frames = 15;
game_player_grounded = false;
}
}
if (game_player_dx < 0) { game_player_faceleft = true; }
if (game_player_dx > 0) { game_player_faceleft = false; }
bool wants_to_go_higher = false;
if (game_player_grounded) {
game_player_coyote_frames = 5;
if (game_player_dy > 0) { game_player_dy = 0; }
if (game_player_dx < 0) { game_player_faceleft = true; }
if (game_player_dx > 0) { game_player_faceleft = false; }
if (sys_abs_i32(game_player_dx) < 0x20) { game_player_dx = 0; }
}
else {
@ -108,7 +117,7 @@ void game_player_update() {
} else {
game_player_anim_transition(GAME_PLAYER_ANIM_WALKING);
game_player_anim_add_progress(
sys_min_i32(sys_abs_i32(game_player_dx) / 0x10, 0x8)
sys_min_i32(sys_abs_i32(game_player_dx) / 0x10, 0x20)
);
}
} else {
@ -138,8 +147,8 @@ void game_player_draw() {
sys_sprite_draw_ext(
spr_game_player,
game_player_image,
game_player_bbox.x / 0x100,
game_player_bbox.y / 0x100,
game_player_bbox.x / 0x100 - GAME_PLAYER_ORIGIN_X,
game_player_bbox.y / 0x100 - GAME_PLAYER_ORIGIN_Y,
2, 2,
game_player_faceleft, false
);

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@ -295,6 +295,24 @@ void sys_map_draw(
}
}
sys_maptile sys_map_get(
sys_map map,
sys_i32 tile_x, sys_i32 tile_y,
bool* flag_invalid
) {
if (flag_invalid != NULL) { *flag_invalid = false; }
if (
tile_x < 0 || tile_y < 0 ||
tile_x >= map.width || tile_y >= map.height
) {
if (flag_invalid != NULL) { *flag_invalid = true; }
return 255;
}
return map.tiles[tile_x + map.width * tile_y];
}
// == internal primitives ==
void sys_pixel_internal_set(sys_i32 x, sys_i32 y, sys_color c) {
sys_color realc = sys_dpal[c];

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@ -179,4 +179,16 @@ void sys_map_draw(
// TODO: Layers?
);
/**
* Get a single map tile, putting whether the coords were invalid into
* flag_invalid.
*
* (flag_invalid may be null)
*/
sys_maptile sys_map_get(
sys_map map,
sys_i32 tile_x, sys_i32 tile_y,
bool* flag_invalid
);
#endif // CROCPARTY_SYS_GRAPHICS_H

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@ -25,9 +25,10 @@ bool sys_btn(DeviceButton button) {
return sys_input_down_frames[button] >= 1;
}
bool sys_btnp(DeviceButton button) {
bool sys_btnp(DeviceButton button, bool repeat) {
if (button >= DEVICE_BUTTON_N) { return false; }
if (sys_input_down_frames[button] == 1) { return true; }
if (!repeat) { return false; }
// 31 and every 8 frames after that
if (sys_input_down_frames[button] >= 31 && (sys_input_down_frames[button] - 31) % 8 == 0) {
return true;

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@ -26,8 +26,9 @@ bool sys_btn(DeviceButton button);
/**
* Return whether a button was just pressed.
*
* Repeats after 30 frames, returning true every 8 frames after that.
* If `repeat`, then this repeats after 30 frames, returning true every 8
* frames after that.
*/
bool sys_btnp(DeviceButton button);
bool sys_btnp(DeviceButton button, bool repeat);
#endif // SYS_INPUT_H