PartsEngine: Implement movie parts

This adds PARTS_MOVIE type which creates a SACT sprite as a render
target for DrawMovie.

The GL texture is shared between the SACT sprite and parts_common, so
movie frames rendered to the sprite are directly visible through the
parts engine's rendering path.

include/parts.h

@@ -116,6 +116,9 @@ bool PE_Load(struct page **buffer);
 // GUIEngine
 int PE_GetFreeNumber(void);
 bool PE_IsExist(int parts_no);
+// PartsFunc interface
+bool PE_init_parts_movie(int parts_no, int width, int height, int bg_r, int bg_g, int bg_b, int state);
+int PE_get_movie_sprite(int parts_no, int state);
 
 // construction.c
 bool PE_AddCreateToPartsConstructionProcess(int parts_no, int w, int h, int state);

src/hll/PartsEngine.c

@@ -18,6 +18,7 @@
 
 #include "system4/ain.h"
 
+#include "vm/page.h"
 #include "parts.h"
 #include "hll.h"
 
@@ -96,7 +97,39 @@ static void PartsEngine_AddComponentMotionPos(int parts_no, float begin_x, float
 			begin_t, end_t, curve_name);
 }
 
-HLL_WARN_UNIMPLEMENTED(0, int, PartsEngine, PartsFunc, int func_id, struct page **array_int, struct page **array_float, struct page **array_string);
+// Generic dispatch function for PartsEngine operations.
+// func_id selects the operation; arguments and return values are passed
+// through three typed arrays (int/bool, float, string).
+//
+// Calling convention (from game script):
+//   1. Push input values into the appropriate arrays.
+//   2. Push a placeholder (0 or "") for each output slot.
+//   3. Call PartsFunc; outputs are written back into the placeholder slots.
+static int PartsEngine_PartsFunc(int func_id, struct page **array_int,
+		struct page **array_float, struct page **array_string)
+{
+	int nr_ints = (array_int && *array_int) ? (*array_int)->nr_vars : 0;
+	union vm_value *ints = nr_ints ? (*array_int)->values : NULL;
+
+#define REQUIRE_INTS(n) \
+	if (nr_ints != (n)) VM_ERROR("Invalid arguments for PartsFunc %d: expected %d ints, got %d", func_id, (n), nr_ints)
+
+	switch (func_id) {
+	case 162:  // bool InitPartsMovie(int parts_no, int width, int height, int bg_r, int bg_g, int bg_b, int state)
+		REQUIRE_INTS(8);
+		ints[7].i = PE_init_parts_movie(ints[0].i, ints[1].i, ints[2].i, ints[3].i, ints[4].i, ints[5].i, ints[6].i);
+		return 1;
+	case 163:  // int GetMovieSprite(int parts_no, int state)
+		REQUIRE_INTS(3);
+		ints[2].i = PE_get_movie_sprite(ints[0].i, ints[1].i);
+		return 1;
+	default:
+		WARNING("Unknown func_id: %d", func_id);
+		return 0;
+	}
+#undef REQUIRE_INTS
+}
+
 HLL_WARN_UNIMPLEMENTED(, void, PartsEngine, StopSoundWithoutSystemSound);
 HLL_WARN_UNIMPLEMENTED(, void, PartsEngine, ReleaseMessage, void);
 HLL_WARN_UNIMPLEMENTED(0, int, PartsEngine, GetMessageType, void);

src/parts/debug.c

@@ -209,6 +209,11 @@ static void parts_flat_to_json(struct parts_flat *flat, cJSON *out, bool verbose
 	cJSON_AddNumberToObject(out, "end_frame", flat->end_frame);
 }
 
+static void parts_movie_to_json(struct parts_movie *movie, cJSON *out, bool verbose)
+{
+	cJSON_AddNumberToObject(out, "sprite_no", movie->sprite_no);
+}
+
 static cJSON *parts_state_to_json(struct parts_state *state, bool verbose)
 {
 	static const char *state_types[PARTS_NR_TYPES] = {
@@ -262,6 +267,9 @@ static cJSON *parts_state_to_json(struct parts_state *state, bool verbose)
 	case PARTS_FLAT:
 		parts_flat_to_json(&state->flat, obj, verbose);
 		break;
+	case PARTS_MOVIE:
+		parts_movie_to_json(&state->movie, obj, verbose);
+		break;
 	}
 
 	return obj;
@@ -545,6 +553,9 @@ static void parts_list_print(struct parts *parts, int indent)
 	case PARTS_FLAT:
 		sys_message("(flat %s)", state->flat.name ? display_sjis0(state->flat.name->text) : "(null)");
 		break;
+	case PARTS_MOVIE:
+		sys_message("(movie sp=%d)", state->movie.sprite_no);
+		break;
 	}
 
 	sys_message(" @ z=%d (%d)\n", parts->global.z, parts->local.z);

src/parts/parts.c

@@ -26,6 +26,7 @@
 #include "vm/page.h"
 #include "xsystem4.h"
 #include "sact.h"
+#include "sprite.h"
 #include "parts.h"
 #include "parts_internal.h"
 
@@ -178,6 +179,12 @@ static void parts_state_free(struct parts_state *state)
 	case PARTS_FLAT:
 		parts_flat_free(&state->flat);
 		break;
+	case PARTS_MOVIE:
+		// The texture is owned by the SACT sprite.
+		state->common.texture.handle = 0;
+		if (state->movie.sprite_no >= 0)
+			sact_SP_Delete(state->movie.sprite_no);
+		break;
 	}
 	memset(state, 0, sizeof(struct parts_state));
 }
@@ -225,6 +232,9 @@ void parts_state_reset(struct parts_state *state, enum parts_type type)
 	case PARTS_FLASH:
 	case PARTS_FLAT:
 		break;
+	case PARTS_MOVIE:
+		state->movie.sprite_no = -1;
+		break;
 	}
 }
 
@@ -300,6 +310,14 @@ struct parts_flat *parts_get_flat(struct parts *parts, int state)
 	return &parts->states[state].flat;
 }
 
+struct parts_movie *parts_get_movie(struct parts *parts, int state)
+{
+	if (parts->states[state].type != PARTS_MOVIE) {
+		parts_state_reset(&parts->states[state], PARTS_MOVIE);
+	}
+	return &parts->states[state].movie;
+}
+
 static Point calculate_offset(int mode, int w, int h)
 {
 	switch (mode) {
@@ -1861,3 +1879,36 @@ void PE_SetSpeedupRateByMessageSkip(int parts_no, int rate)
 	if (rate != 1)
 		UNIMPLEMENTED("(%d, %d)");
 }
+
+bool PE_init_parts_movie(int parts_no, int width, int height, int bg_r, int bg_g, int bg_b, int state)
+{
+	if (!parts_state_valid(--state))
+		return false;
+
+	struct parts *parts = parts_get(parts_no);
+	struct parts_movie *movie = parts_get_movie(parts, state);
+
+	int sp_no = sact_SP_GetUnuseNum(0);
+	struct sact_sprite *sp = sact_create_sprite(sp_no, width, height, bg_r, bg_g, bg_b, 255);
+	if (!sp)
+		return false;
+
+	struct texture *tex = sprite_get_texture(sp);
+	movie->sprite_no = sp_no;
+	movie->common.texture = *tex; // XXX: textures normally shouldn't be copied like this...
+	parts_set_dims(parts, &movie->common, width, height);
+	parts_dirty(parts);
+	return true;
+}
+
+int PE_get_movie_sprite(int parts_no, int state)
+{
+	if (!parts_state_valid(--state))
+		return -1;
+
+	struct parts *parts = parts_try_get(parts_no);
+	if (!parts || parts->states[state].type != PARTS_MOVIE)
+		return -1;
+
+	return parts->states[state].movie.sprite_no;
+}

src/parts/parts_internal.h

@@ -104,7 +104,8 @@ enum parts_type {
 	PARTS_CONSTRUCTION_PROCESS,
 	PARTS_FLASH,
 	PARTS_FLAT,
-#define PARTS_NR_TYPES (PARTS_FLAT+1)
+	PARTS_MOVIE,
+#define PARTS_NR_TYPES (PARTS_MOVIE+1)
 };
 
 struct parts_common {
@@ -313,6 +314,11 @@ struct parts_flat {
 	size_t nr_textures;
 };
 
+struct parts_movie {
+	struct parts_common common;
+	int sprite_no;  // SACT sprite number used as movie render target
+};
+
 struct parts_state {
 	enum parts_type type;
 	union {
@@ -325,6 +331,7 @@ struct parts_state {
 		struct parts_construction_process cproc;
 		struct parts_flash flash;
 		struct parts_flat flat;
+		struct parts_movie movie;
 	};
 };
 
@@ -385,6 +392,7 @@ struct parts_gauge *parts_get_vgauge(struct parts *parts, int state);
 struct parts_construction_process *parts_get_construction_process(struct parts *parts, int state);
 struct parts_flash *parts_get_flash(struct parts *parts, int state);
 struct parts_flat *parts_get_flat(struct parts *parts, int state);
+struct parts_movie *parts_get_movie(struct parts *parts, int state);
 void parts_set_pos(struct parts *parts, Point pos);
 void parts_set_global_pos(Point pos);
 void parts_set_dims(struct parts *parts, struct parts_common *common, int w, int h);

src/parts/render.c

@@ -419,6 +419,7 @@ void parts_render(struct parts *parts)
 	case PARTS_HGAUGE:
 	case PARTS_VGAUGE:
 	case PARTS_CONSTRUCTION_PROCESS:
+	case PARTS_MOVIE:
 		if (state->common.texture.handle)
 			parts_render_cg(parts, &state->common);
 		break;

src/parts/save.c

@@ -386,6 +386,8 @@ static void save_parts_state(struct iarray_writer *w, struct parts_state *state)
 	case PARTS_FLAT:
 		save_parts_flat(w, &state->flat);
 		break;
+	case PARTS_MOVIE:
+		break;
 	}
 }
 
@@ -428,6 +430,8 @@ static void load_parts_state(struct iarray_reader *r, struct parts *parts,
 	case PARTS_FLAT:
 		load_parts_flat(r, parts, &state->flat);
 		break;
+	case PARTS_MOVIE:
+		break;
 	}
 }