modules/*: first stab at utilizing supplied seeds

This is a mostly mechanical change of using rand_r() in place of
rand(), using the provided seed as the seed state.

There's some outstanding rand()s outside of create_context()
which should probably get switched over, with the seed being
stowed in the context struct.  I didn't bother going deeper on
this at the moment in the interests of getting to sleep soon.

11 files changed, 33 insertions, 28 deletions

diff --git a/src/modules/compose/compose.c b/src/modules/compose/compose.c
index b0f0104..f55e516 100644
--- a/src/modules/compose/compose.c
+++ b/src/modules/compose/compose.c
@@ -90,7 +90,7 @@ static void * compose_create_context(unsigned seed, unsigned ticks, unsigned n_c
 		(void) til_module_randomize_setup(layer_module, &layer_setup, NULL);
 
 		ctxt->layers[i].module = layer_module;
-		(void) til_module_create_context(layer_module, rand(), ticks, layer_setup, &ctxt->layers[i].module_ctxt);
+		(void) til_module_create_context(layer_module, rand_r(&seed), ticks, layer_setup, &ctxt->layers[i].module_ctxt);
 		til_setup_free(layer_setup);
 
 		ctxt->n_layers++;
@@ -102,7 +102,7 @@ static void * compose_create_context(unsigned seed, unsigned ticks, unsigned n_c
 		ctxt->texture.module = til_lookup_module(((compose_setup_t *)setup)->texture);
 		(void) til_module_randomize_setup(ctxt->texture.module, &texture_setup, NULL);
 
-		(void) til_module_create_context(ctxt->texture.module, rand(), ticks, texture_setup, &ctxt->texture.module_ctxt);
+		(void) til_module_create_context(ctxt->texture.module, rand_r(&seed), ticks, texture_setup, &ctxt->texture.module_ctxt);
 		til_setup_free(texture_setup);
 	}
 
diff --git a/src/modules/julia/julia.c b/src/modules/julia/julia.c
index c24e40a..d9cfdff 100644
--- a/src/modules/julia/julia.c
+++ b/src/modules/julia/julia.c
@@ -73,7 +73,7 @@ static void * julia_create_context(unsigned seed, unsigned ticks, unsigned n_cpu
 	if (!ctxt)
 		return NULL;
 
-	ctxt->rr = ((float)rand()) / (float)RAND_MAX * 100.f;
+	ctxt->rr = ((float)rand_r(&seed)) / (float)RAND_MAX * 100.f;
 
 	return ctxt;
 }
diff --git a/src/modules/meta2d/meta2d.c b/src/modules/meta2d/meta2d.c
index 8b87804..d1063de 100644
--- a/src/modules/meta2d/meta2d.c
+++ b/src/modules/meta2d/meta2d.c
@@ -78,8 +78,9 @@ static void * meta2d_create_context(unsigned seed, unsigned ticks, unsigned n_cp
 	for (int i = 0; i < META2D_NUM_BALLS; i++) {
 		meta2d_ball_t	*ball = &ctxt->balls[i];
 
+		/* TODO: add _r() variants of v[23]f_rand()? */
 		v2f_rand(&ball->position, &(v2f_t){-.7f, -.7f}, &(v2f_t){.7f, .7f});
-		ball->radius = rand() / (float)RAND_MAX * .2f + .05f;
+		ball->radius = rand_r(&seed) / (float)RAND_MAX * .2f + .05f;
 		v3f_rand(&ball->color, &(v3f_t){0.f, 0.f, 0.f}, &(v3f_t){1.f, 1.f, 1.f});
 	}
 
diff --git a/src/modules/montage/montage.c b/src/modules/montage/montage.c
index a7030ff..1b79de5 100644
--- a/src/modules/montage/montage.c
+++ b/src/modules/montage/montage.c
@@ -90,7 +90,7 @@ static void * montage_create_context(unsigned seed, unsigned ticks, unsigned n_c
 		(void) til_module_randomize_setup(module, &setup, NULL);
 
 		if (module->create_context)	/* FIXME errors */
-			ctxt->contexts[i] = module->create_context(rand(), ticks, 1, setup);
+			ctxt->contexts[i] = module->create_context(rand_r(&seed), ticks, 1, setup);
 
 		til_setup_free(setup);
 	}
diff --git a/src/modules/plasma/plasma.c b/src/modules/plasma/plasma.c
index aca4e85..dfcbd15 100644
--- a/src/modules/plasma/plasma.c
+++ b/src/modules/plasma/plasma.c
@@ -66,7 +66,7 @@ static void * plasma_create_context(unsigned seed, unsigned ticks, unsigned n_cp
 	if (!ctxt)
 		return NULL;
 
-	ctxt->rr = rand();
+	ctxt->rr = rand_r(&seed);
 
 	return ctxt;
 }
diff --git a/src/modules/roto/roto.c b/src/modules/roto/roto.c
index 0969929..8908bd2 100644
--- a/src/modules/roto/roto.c
+++ b/src/modules/roto/roto.c
@@ -39,8 +39,8 @@ static void * roto_create_context(unsigned seed, unsigned ticks, unsigned n_cpus
 	if (!ctxt)
 		return NULL;
 
-	ctxt->r = rand();
-	ctxt->rr = rand();
+	ctxt->r = rand_r(&seed);
+	ctxt->rr = rand_r(&seed);
 
 	return ctxt;
 }
diff --git a/src/modules/rtv/rtv.c b/src/modules/rtv/rtv.c
index 6cd9744..3e789ab 100644
--- a/src/modules/rtv/rtv.c
+++ b/src/modules/rtv/rtv.c
@@ -242,7 +242,7 @@ static void * rtv_create_context(unsigned seed, unsigned ticks, unsigned n_cpus,
 	ctxt->snow_channel.module = &rtv_none_module;
 	if (((rtv_setup_t *)setup)->snow_module) {
 		ctxt->snow_channel.module = til_lookup_module(((rtv_setup_t *)setup)->snow_module);
-		(void) til_module_create_context(ctxt->snow_channel.module, rand(), ticks, NULL, &ctxt->snow_channel.module_ctxt);
+		(void) til_module_create_context(ctxt->snow_channel.module, rand_r(&seed), ticks, NULL, &ctxt->snow_channel.module_ctxt);
 	}
 
 	for (size_t i = 0; i < n_modules; i++) {
diff --git a/src/modules/snow/snow.c b/src/modules/snow/snow.c
index 82ad847..bf0aee0 100644
--- a/src/modules/snow/snow.c
+++ b/src/modules/snow/snow.c
@@ -10,8 +10,8 @@
 /* This implements white noise / snow just using rand() */
 
 typedef union snow_seed_t {
-	char	__padding[256];		/* prevent seeds sharing a cache-line */
-	int	seed;
+	char		__padding[256];		/* prevent seeds sharing a cache-line */
+	unsigned	seed;
 } snow_seed_t;
 
 typedef struct snow_context_t {
@@ -29,7 +29,7 @@ static void * snow_create_context(unsigned seed, unsigned ticks, unsigned n_cpus
 		return NULL;
 
 	for (unsigned i = 0; i < n_cpus; i++)
-		ctxt->seeds[i].seed = rand();
+		ctxt->seeds[i].seed = rand_r(&seed);
 
 	return ctxt;
 }
@@ -50,7 +50,7 @@ static void snow_prepare_frame(void *context, unsigned ticks, unsigned n_cpus, t
 static void snow_render_fragment(void *context, unsigned ticks, unsigned cpu, til_fb_fragment_t *fragment)
 {
 	snow_context_t	*ctxt = context;
-	int		*seed = &ctxt->seeds[cpu].seed;
+	unsigned	*seed = &ctxt->seeds[cpu].seed;
 
 	for (unsigned y = fragment->y; y < fragment->y + fragment->height; y++) {
 		for (unsigned x = fragment->x; x < fragment->x + fragment->width; x++) {
diff --git a/src/modules/spiro/spiro.c b/src/modules/spiro/spiro.c
index 07d9fbf..a2adb7b 100644
--- a/src/modules/spiro/spiro.c
+++ b/src/modules/spiro/spiro.c
@@ -38,12 +38,12 @@ static void * spiro_create_context(unsigned seed, unsigned ticks, unsigned n_cpu
 	if (!ctxt)
 		return NULL;
 
-	ctxt->r=.25f+(rand()/(float)RAND_MAX)*.5f;
+	ctxt->r=.25f+(rand_r(&seed)/(float)RAND_MAX)*.5f;
 	if(ctxt->r>.5f)
 		ctxt->r_dir=-1;
 	else
 		ctxt->r_dir=1;
-	ctxt->p=(rand()/(float)RAND_MAX)*ctxt->r;
+	ctxt->p=(rand_r(&seed)/(float)RAND_MAX)*ctxt->r;
 	ctxt->p_dir=ctxt->r_dir*-1;
 #ifdef DEBUG
 	printf("spiro: initial context: r=%f, dir=%i, p=%f, dir=%i\n", ctxt->r, ctxt->r_dir, ctxt->p, ctxt->p_dir);
diff --git a/src/modules/stars/stars.c b/src/modules/stars/stars.c
index 21ae7f5..5506559 100644
--- a/src/modules/stars/stars.c
+++ b/src/modules/stars/stars.c
@@ -32,6 +32,7 @@ typedef struct stars_context_t {
 	float		offset_x;
 	float		offset_y;
 	float		offset_angle;
+	unsigned	seed;
 } stars_context_t;
 
 typedef struct stars_setup_t {
@@ -44,8 +45,8 @@ static stars_setup_t stars_default_setup = {
 };
 
 
-float get_random_unit_coord() {
-	return (((float)rand()/(float)RAND_MAX)*2.0)-1.0;
+float get_random_unit_coord(unsigned *seed) {
+	return (((float)rand_r(seed)/(float)RAND_MAX)*2.0)-1.0;
 }
 
 
@@ -63,6 +64,7 @@ static void * stars_create_context(unsigned seed, unsigned ticks, unsigned n_cpu
 		return NULL;
 
 	ctxt->points = NULL;
+	ctxt->seed = seed;
 	ctxt->rot_adj = ((stars_setup_t *)setup)->rot_adj;
 	ctxt->rot_rate = 0.00;
 	ctxt->rot_angle = 0;
@@ -72,12 +74,12 @@ static void * stars_create_context(unsigned seed, unsigned ticks, unsigned n_cpu
 
 	//add a bunch of points
 	for(z=0.01; z<1; z=z+0.01) {
-		for(int i=0; i<rand()%16; i++){
+		for(int i=0; i<rand_r(&ctxt->seed)%16; i++){
 			p_ptr = malloc(sizeof(struct points));
 			if (!p_ptr)
 				return NULL;
-			p_ptr->x = get_random_unit_coord();
-			p_ptr->y = get_random_unit_coord();
+			p_ptr->x = get_random_unit_coord(&ctxt->seed);
+			p_ptr->y = get_random_unit_coord(&ctxt->seed);
 			p_ptr->z = z;
 			p_ptr->next = ctxt->points;
 			ctxt->points = p_ptr;
@@ -185,12 +187,12 @@ static void stars_render_fragment(void *context, unsigned ticks, unsigned cpu, t
 	}
 
 	// add stars at horizon
-	for(int i=0; i<rand()%16; i++){
+	for(int i=0; i<rand_r(&ctxt->seed)%16; i++){
 		tmp_ptr = malloc(sizeof(struct points));
 		if (!tmp_ptr)
 			break;
-		tmp_ptr->x = get_random_unit_coord();
-		tmp_ptr->y = get_random_unit_coord();
+		tmp_ptr->x = get_random_unit_coord(&ctxt->seed);
+		tmp_ptr->y = get_random_unit_coord(&ctxt->seed);
 		tmp_ptr->z = 0.01;
 		tmp_ptr->next = ctxt->points;
 		ctxt->points = tmp_ptr;
diff --git a/src/modules/voronoi/voronoi.c b/src/modules/voronoi/voronoi.c
index 0a9ba70..adb180d 100644
--- a/src/modules/voronoi/voronoi.c
+++ b/src/modules/voronoi/voronoi.c
@@ -42,6 +42,7 @@ typedef struct voronoi_distances_t {
 } voronoi_distances_t;
 
 typedef struct voronoi_context_t {
+	unsigned		seed;
 	voronoi_setup_t		setup;
 	voronoi_distances_t	distances;
 	voronoi_cell_t		cells[];
@@ -67,12 +68,12 @@ static void voronoi_randomize(voronoi_context_t *ctxt)
 	for (size_t i = 0; i < ctxt->setup.n_cells; i++) {
 		voronoi_cell_t	*p = &ctxt->cells[i];
 
-		p->origin.x = ((float)rand() * inv_rand_max) * 2.f - 1.f;
-		p->origin.y = ((float)rand() * inv_rand_max) * 2.f - 1.f;
+		p->origin.x = ((float)rand_r(&ctxt->seed) * inv_rand_max) * 2.f - 1.f;
+		p->origin.y = ((float)rand_r(&ctxt->seed) * inv_rand_max) * 2.f - 1.f;
 
-		p->color = ((uint32_t)(rand() % 256)) << 16;
-		p->color |= ((uint32_t)(rand() % 256)) << 8;
-		p->color |= ((uint32_t)(rand() % 256));
+		p->color = ((uint32_t)(rand_r(&ctxt->seed) % 256)) << 16;
+		p->color |= ((uint32_t)(rand_r(&ctxt->seed) % 256)) << 8;
+		p->color |= ((uint32_t)(rand_r(&ctxt->seed) % 256));
 	}
 }
 
@@ -89,6 +90,7 @@ static void * voronoi_create_context(unsigned seed, unsigned ticks, unsigned n_c
 		return NULL;
 
 	ctxt->setup = *(voronoi_setup_t *)setup;
+	ctxt->seed = seed;
 
 	voronoi_randomize(ctxt);