Correctly render sprites #5

Merged
Sara merged 6 commits from fix-render into main 2023-06-18 09:24:13 +00:00
4 changed files with 184 additions and 6 deletions

4
.gitignore vendored
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@ -1,3 +1,6 @@
# ide files
.nvimrc
# build dirs
bin/
release/
@ -8,3 +11,4 @@ compile_commands.json
# clangd cache
.cache/
.helix

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@ -80,10 +80,10 @@ static
void _exec_sprite_cmd(const drawcmd_t* cmd) {
const sprite_t* sprite = &cmd->sprite;
SDL_FRect untransformed = {sprite->x, sprite->y, sprite->sx, sprite->sy};
untransformed.x -= sprite->origin.x;
untransformed.y -= sprite->origin.y;
SDL_FRect destrect = get_dest_with_size(untransformed, cmd->ui);
SDL_FPoint origin = {destrect.w * sprite->origin.x, destrect.h * sprite->origin.y};
destrect.x -= origin.x;
destrect.y -= origin.y;
SDL_RenderCopyExF(g_context.renderer, sprite->texture,
&sprite->uv, &destrect, sprite->rot,
&origin, sprite->flip);
@ -443,7 +443,7 @@ sprite_t make_sprite(const char* file, float x, float y) {
sprite_t sprite=(sprite_t){
.texture=get_texture(file),
.x=x,.y=y,
.origin=(SDL_FPoint){.x=0,.y=0},
.origin=(SDL_FPoint){.x=0.0,.y=0.0},
.sx=1.0,.sy=1.0,
.rot=0,
.depth=RLAYER_SPRITES,
@ -451,7 +451,6 @@ sprite_t make_sprite(const char* file, float x, float y) {
.flip=SDL_FLIP_NONE,
};
SDL_QueryTexture(sprite.texture, NULL, NULL, &sprite.uv.w, &sprite.uv.h);
sprite.origin.x = -(float)sprite.uv.h/2.f; sprite.origin.y = -(float)sprite.uv.h/2.f;
return sprite;
}

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@ -26,6 +26,7 @@ object_t* make_object() {
object_t* o = _find_free_object();
o->active = 1;
o->enabled = 1;
o->collider = collider_default();
o->evt_draw = &object_draw_sprite;
o->evt_update = NULL;
memset(&o->sprite, 0, sizeof(sprite_t));
@ -39,6 +40,12 @@ object_t* instantiate_object(const object_t *original) {
return obj;
}
collider_t collider_default() {
return (collider_t) {
.type=COLLIDERTYPE_NONE
};
}
void update_objects() {
for(int i = 0; i < WORLD_NUM_OBJECTS; ++i) {
if(g_objects[i].active == 1
@ -58,3 +65,142 @@ void draw_objects() {
}
}
}
static inline
int _rect_overlap(float aminx, float aminy, float amaxx, float amaxy, float bminx, float bminy, float bmaxx, float bmaxy) {
return
(
(aminx < bmaxx && aminx > bmaxx)
||
(amaxx > bminx && amaxx < bmaxx)
) && (
(aminy < bmaxy && aminy > bmaxy)
||
(amaxy > bminy && amaxy < bmaxy)
);
}
static inline
short _collision_aabb_aabb(const object_t* a, const object_t* b) {
const float aminx = a->collider.aabb.x + a->sprite.x, aminy = a->collider.aabb.y + a->sprite.x;
const float amaxx = aminx + a->collider.aabb.w, amaxy = aminy + a->collider.aabb.h;
const float bminx = b->collider.aabb.x, bminy = b->collider.aabb.y;
const float bmaxx = b->collider.aabb.x + b->collider.aabb.w, bmaxy = b->collider.aabb.y + b->collider.aabb.h;
return _rect_overlap(aminx, aminy, amaxx, amaxy, bminx, bminy, bmaxx, bmaxy);
}
static inline
short _collision_circle_circle(const object_t* a, const object_t* b) {
const float ax = a->sprite.x + a->collider.circle.x, ay = a->sprite.y + a->collider.circle.y,
bx = b->sprite.x + b->collider.circle.x, by = b->sprite.y + b->collider.circle.y;
const float dx = fabsf(ax-bx), dy = fabsf(ay-by);
const float sqrdist = dx*dx+dy*dy;
const float mindist = a->collider.circle.radius + b->collider.circle.radius;
const float mindistsqr = mindist*mindist;
return sqrdist < mindistsqr;
}
static inline
float fclampf(float x, float min_, float max_) {
return fminf(max_, fmaxf(min_, x));
}
static inline
short _collision_circle_aabb(const object_t* circle, const object_t* aabb) {
// generate a point on the edge of the rectangle that is closest to the circle
const float bbminx = aabb->collider.aabb.x + aabb->sprite.x, bbmaxx = bbminx + aabb->collider.aabb.w,
bbminy = aabb->collider.aabb.y + aabb->sprite.x, bbmaxy = bbminy + aabb->collider.aabb.h;
const float cx = circle->sprite.x + circle->collider.circle.x,
cy = circle->sprite.y + circle->collider.circle.y;
const float x = fclampf(cx, bbminx, bbmaxx),
y = fclampf(cy, bbminy, bbmaxy);
const float dx = fabsf(cx - x), dy = fabsf(cy - y);
// calculate the square distance from the centre of the circle to the edge of the aabb
const float distsqr = dx*dx+dy*dy;
const float rsqr = circle->collider.circle.radius*circle->collider.circle.radius;
// return if the square distance is larger than the square of the radius
return distsqr < rsqr;
}
static inline
short _collision_check(const object_t* a, const object_t* b) {
if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_AABB) {
return _collision_aabb_aabb(a, b);
} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_CIRCLE) {
return _collision_circle_circle(a, b);
} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_AABB) {
return _collision_circle_aabb(a, b);
} else if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_CIRCLE) {
return _collision_circle_aabb(b, a);
}
return 0;
}
static inline
short _can_collide(const object_t* object) {
return object->active && object->enabled && object->collider.evt_collision != NULL;
}
void update_collision() {
for(int outer = 0; outer < WORLD_NUM_OBJECTS; ++outer) {
object_t* oobject = g_objects + outer;
if(!_can_collide(oobject)) continue;
for(int inner = 0; inner < WORLD_NUM_OBJECTS; ++inner) {
object_t* iobject = g_objects + inner;
if(!_can_collide(oobject)) continue;
if(outer != inner && _collision_check(iobject, oobject)) {
oobject->collider.evt_collision(oobject, iobject);
iobject->collider.evt_collision(iobject, oobject);
}
}
}
}
object_t* interpolate_move(object_t* object, float target_x, float target_y, float max_step_size) {
// calculate step delta
float dx = target_x - object->sprite.x, dy = target_y - object->sprite.y;
// calculate direction x,y
float m = sqrtf(dx*dx + dy*dy);
dx /= m; dy /= m;
dx *= max_step_size; dy *= max_step_size;
// ensure this object would ever collide
// if it wouldn't collide anyway, just set position
if(_can_collide(object)) {
object->sprite.x = target_x;
object->sprite.y = target_y;
return NULL;
}
/*
* 1. check collision with every other object
* 2. move towards target
*/
while(object->sprite.x != target_x || object->sprite.y != target_y) {
for(int i = 0; i < WORLD_NUM_OBJECTS; ++i) {
object_t* other = g_objects + i;
if(!_can_collide(other)) continue;
if(object != other && _collision_check(other, object)) {
other->collider.evt_collision(other, object);
object->collider.evt_collision(object, other);
return other;
}
}
// move towards target, snap to target if distance is too low
float distx = fabsf(object->sprite.x - target_x), disty = fabsf(object->sprite.y - target_y);
if(distx < fabsf(dx) && disty < fabsf(dy)) {
object->sprite.x += dx; object->sprite.y += dy;
} else {
object->sprite.x = target_x;
object->sprite.y = target_y;
}
}
// no collision, return nothing
return NULL;
}

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@ -10,11 +10,33 @@ typedef struct object_t object_t;
typedef void(*tick_fn)(struct object_t*);
typedef void(*draw_fn)(struct object_t*);
typedef void(*collided_fn)(struct object_t*, struct object_t*);
typedef enum collider_type_t {
COLLIDERTYPE_MIN,
COLLIDERTYPE_NONE,
COLLIDERTYPE_CIRCLE,
COLLIDERTYPE_AABB,
COLLIDERTYPE_MAX,
} collider_type_t;
typedef struct collider_t {
collider_type_t type;
collided_fn evt_collision;
union {
struct {
float x, y;
float radius;
} circle;
SDL_FRect aabb;
};
} collider_t;
struct object_t {
sprite_t sprite;
int active; // 1 if this object is in use and should not be overriden
int enabled; // 1 if this object's events should be triggered
int active; // 1 if this object is in use and should not be overriden.
int enabled; // 1 if this object's events should be triggered.
collider_t collider; // the collider to use for this object's physics interaction.
uintptr_t timer; // free to use for whatever
@ -26,12 +48,19 @@ extern object_t g_objects[WORLD_NUM_OBJECTS];
void world_clear();
object_t* make_object();
object_t* instantiate_object(const object_t* original);
collider_t collider_default();
void object_draw_sprite(object_t* object);
void update_objects();
void draw_objects();
void update_collision();
object_t* interpolate_move(object_t* object, float target_x, float target_y, float max_step_size);
#endif /* _world_h */