overengineer entityimpl a bit more

src/deathpart.c

@@ -3,6 +3,16 @@
 #include "entityimpl.h"
 #include <stdlib.h>
 
+IMPL_INIT(deathpart) {
+	this->ignore_solids = true;
+	this->vel[0] = (float)(rand() % 1024) / 1024;
+	this->vel[1] = -(float)(rand() % 1024) / 512;
+	this->vel[0] *= this->vel[0];
+	if (rand() % 2)
+		this->vel[0] *= -1;
+	this->width = 1 + rand() % 2;
+}
+
 IMPL(update) {
 	if (this->deathpart.skip == 0) {
 		this->vel[1] *= AIR_RESISTANCE;
@@ -21,13 +31,3 @@ IMPL(draw) {
 		(void)LZY_DrawRect(this->pos[0], this->pos[1],
 		                   this->width, this->width);
 }
-
-IMPL_INIT(deathpart) {
-	this->ignore_solids = true;
-	this->vel[0] = (float)(rand() % 1024) / 1024;
-	this->vel[1] = -(float)(rand() % 1024) / 512;
-	this->vel[0] *= this->vel[0];
-	if (rand() % 2)
-		this->vel[0] *= -1;
-	this->width = 1 + rand() % 2;
-} IMPL_END

src/entity.c

@@ -100,5 +100,6 @@ entity_move(Entity *this, Game *g)
 Entity *
 entity_init(Entity *this, unsigned int type, int x, int y)
 {
-	return entitytags[type - 1].init(this, x, y);
+	entitytags[type - 1].init(this, x, y);
+	return this;
 }

src/entityimpl.h

@@ -5,22 +5,26 @@
 #include "entitytag.h"
 #include <string.h>
 
-#define IMPL(X) static void \
-X([[maybe_unused]] Entity *this, [[maybe_unused]] Game *g)
+[[maybe_unused]] static void *_draw;
+[[maybe_unused]] static void *_update;
 
-#define IMPL_INIT(X) static Entity *init(Entity *this, int x, int y); \
+#define IMPL(X) static void X(Entity *this, Game *g); \
+__attribute__((constructor)) static void init_##X() { _##X = X; } \
+static void X([[maybe_unused]] Entity *this, [[maybe_unused]] Game *g)
+
+#define IMPL_INIT(X) static void init(Entity *this, int x, int y); \
 __attribute__((constructor)) static void init_tag() { \
 	entitytags[num_entitytags].init = init; \
 	entitytags[num_entitytags++].name = #X; \
 } \
-static Entity * \
-init(Entity *this, int x, int y) { do { \
+static void _init(Entity *this); \
+static void init(Entity *this, int x, int y) { \
 	memset(this, 0, sizeof(*this)); \
-	this->update = update; \
-	this->draw = draw; \
+	this->update = _update; \
+	this->draw = _draw; \
 	this->pos[0] = x; \
 	this->pos[1] = y; \
 	this->type = entity_type(#X); \
-} while(0);
-
-#define IMPL_END return this; }
+	_init(this); \
+} \
+static void _init([[maybe_unused]] Entity *this)

src/entitytag.h

@@ -3,7 +3,7 @@
 
 typedef struct {
 	const char *name;
-	Entity *(*init)(Entity *this, int x, int y);
+	void (*init)(Entity *this, int x, int y);
 } EntityTag;
 
 extern unsigned int num_entitytags;

src/exit.c

@@ -1,7 +1,10 @@
 #include "entityimpl.h"
 #include "rotrect.h"
 
-IMPL(update) {
+IMPL_INIT(exit) {
+	this->width = 12;
+	this->height = 12;
+	this->exit.dir = 1;
 }
 
 IMPL(draw) {
@@ -9,9 +12,3 @@ IMPL(draw) {
 	rotrect(this->pos[0], this->pos[1],
 	        this->width, this->height, 0.2 * this->exit.dir);
 }
-
-IMPL_INIT(exit) {
-	this->width = 12;
-	this->height = 12;
-	this->exit.dir = 1;
-} IMPL_END

src/player.c

@@ -5,6 +5,22 @@
 #include "rotrect.h"
 #include <math.h>
 
+IMPL_INIT(player) {
+	this->width = 10;
+	this->height = 10;
+	this->player.scale_x = 1.0;
+	this->player.scale_y = 1.0;
+	this->player.dirx = 1;
+}
+
+IMPL(draw) {
+	LZY_DrawSetColor(BLACK);
+	const double width = this->width * this->player.scale_x + 2;
+	const double height = this->height * this->player.scale_y + 2;
+	rotrect(this->pos[0] - 1, this->pos[1] - 1,
+	        width, height, this->player.angle);
+}
+
 IMPL(update) {
 	const int on_ground = entity_collide(this, g, 0, 1);
 
@@ -72,19 +88,3 @@ IMPL(update) {
 	if (entity_place_meeting(this, g, entity_type("exit")) != NULL)
 		g->queue_next_scene = true;
 }
-
-IMPL(draw) {
-	LZY_DrawSetColor(BLACK);
-	const double width = this->width * this->player.scale_x + 2;
-	const double height = this->height * this->player.scale_y + 2;
-	rotrect(this->pos[0] - 1, this->pos[1] - 1,
-	        width, height, this->player.angle);
-}
-
-IMPL_INIT(player) {
-	this->width = 10;
-	this->height = 10;
-	this->player.scale_x = 1.0;
-	this->player.scale_y = 1.0;
-	this->player.dirx = 1;
-} IMPL_END

src/spike.c

@@ -1,13 +1,11 @@
 #include "entityimpl.h"
 #include "rotrect.h"
 
-IMPL(update) {}
+IMPL_INIT(spike) {
+	this->height = this->width = 8;
+}
 
 IMPL(draw) {
 	rotrect_draw(g->spike_rect, this->pos[0], this->pos[1]);
 	rotrect_draw(g->spike_irect, this->pos[0], this->pos[1]);
 }
-
-IMPL_INIT(spike) {
-	this->height = this->width = 8;
-} IMPL_END