Merge pull request #36 from npisanti/master

less deterministic random

sim.c

@@ -142,6 +142,7 @@ typedef struct {
   Glyph* vars_slots;
   Piano_bits piano_bits;
   Oevent_list* oevent_list;
+  Usz random_seed;
 } Oper_extra_params;
 
 static void oper_poke_and_stun(Glyph* restrict gbuffer, Mark* restrict mbuffer,
@@ -664,8 +665,8 @@ BEGIN_OPERATOR(random)
     min = b;
     max = a;
   }
-  Usz key = y * width + x;
-  key = hash32_shift_mult((y * width + x) ^ (Tick_number << UINT32_C(16)));
+  Usz key = hash32_shift_mult((extra_params->random_seed + y * width + x) ^
+                              (Tick_number << UINT32_C(16)));
   Usz val = key % (max - min) + min;
   POKE(1, 0, glyph_of(val));
 END_OPERATOR
@@ -769,8 +770,8 @@ END_OPERATOR
 //////// Run simulation
 
 void orca_run(Glyph* restrict gbuf, Mark* restrict mbuf, Usz height, Usz width,
-              Usz tick_number, Oevent_list* oevent_list,
-              Piano_bits piano_bits) {
+              Usz tick_number, Oevent_list* oevent_list, Piano_bits piano_bits,
+              Usz random_seed) {
   Glyph vars_slots[Glyphs_index_count];
   memset(vars_slots, '.', sizeof(vars_slots));
   mbuffer_clear(mbuf, height, width);
@@ -779,6 +780,7 @@ void orca_run(Glyph* restrict gbuf, Mark* restrict mbuf, Usz height, Usz width,
   extras.vars_slots = &vars_slots[0];
   extras.piano_bits = piano_bits;
   extras.oevent_list = oevent_list;
+  extras.random_seed = random_seed;
 
   for (Usz iy = 0; iy < height; ++iy) {
     Glyph const* glyph_row = gbuf + iy * width;

sim.h

@@ -15,6 +15,8 @@ static inline Piano_bits piano_bits_of(Glyph g) {
   return UINT64_C(0);
 }
 
+void init_random_seed(Usz value);
+
 void orca_run(Glyph* restrict gbuffer, Mark* restrict mbuffer, Usz height,
               Usz width, Usz tick_number, Oevent_list* oevent_list,
-              Piano_bits piano_bits);
+              Piano_bits piano_bits, Usz random_seed);

tui_main.c

@@ -768,8 +768,45 @@ typedef struct {
   bool is_mouse_down : 1;
   bool is_mouse_dragging : 1;
   bool is_hud_visible : 1;
+  Usz random_seed;
 } Ged;
 
+// for initializing random, unsed in ged_init
+// http://www.concentric.net/~Ttwang/tech/inthash.htm
+Usz random_seed_mix(void) {
+  Isz a = (Isz)clock();
+  Isz b = (Isz)time(NULL);
+  Isz c = (Isz)getpid();
+  a = a - b;
+  a = a - c;
+  a = a ^ (c >> 13);
+  b = b - c;
+  b = b - a;
+  b = b ^ (a << 8);
+  c = c - a;
+  c = c - b;
+  c = c ^ (b >> 13);
+  a = a - b;
+  a = a - c;
+  a = a ^ (c >> 12);
+  b = b - c;
+  b = b - a;
+  b = b ^ (a << 16);
+  c = c - a;
+  c = c - b;
+  c = c ^ (b >> 5);
+  a = a - b;
+  a = a - c;
+  a = a ^ (c >> 3);
+  b = b - c;
+  b = b - a;
+  b = b ^ (a << 10);
+  c = c - a;
+  c = c - b;
+  c = c ^ (b >> 15);
+  return (Usz)c;
+}
+
 void ged_init(Ged* a, Usz undo_limit, Usz init_bpm) {
   field_init(&a->field);
   field_init(&a->scratch_field);
@@ -807,6 +844,7 @@ void ged_init(Ged* a, Usz undo_limit, Usz init_bpm) {
   a->is_mouse_down = false;
   a->is_mouse_dragging = false;
   a->is_hud_visible = false;
+  a->random_seed = random_seed_mix();
 }
 
 void ged_deinit(Ged* a) {
@@ -1105,7 +1143,7 @@ void ged_do_stuff(Ged* a) {
     apply_time_to_sustained_notes(oosc_dev, midi_mode, secs_span,
                                   &a->susnote_list, &a->time_to_next_note_off);
     orca_run(a->field.buffer, a->mbuf_r.buffer, a->field.height, a->field.width,
-             a->tick_num, &a->oevent_list, a->piano_bits);
+             a->tick_num, &a->oevent_list, a->piano_bits, a->random_seed);
     ++a->tick_num;
     a->piano_bits = ORCA_PIANO_BITS_NONE;
     a->needs_remarking = true;
@@ -1199,7 +1237,7 @@ void ged_draw(Ged* a, WINDOW* win) {
     mbuf_reusable_ensure_size(&a->mbuf_r, a->field.height, a->field.width);
     orca_run(a->scratch_field.buffer, a->mbuf_r.buffer, a->field.height,
              a->field.width, a->tick_num, &a->scratch_oevent_list,
-             a->piano_bits);
+             a->piano_bits, a->random_seed);
     a->needs_remarking = false;
   }
   int win_h = a->win_h;
@@ -1574,7 +1612,7 @@ void ged_input_cmd(Ged* a, Ged_input_cmd ev) {
   case Ged_input_cmd_step_forward:
     undo_history_push(&a->undo_hist, &a->field, a->tick_num);
     orca_run(a->field.buffer, a->mbuf_r.buffer, a->field.height, a->field.width,
-             a->tick_num, &a->oevent_list, a->piano_bits);
+             a->tick_num, &a->oevent_list, a->piano_bits, a->random_seed);
     ++a->tick_num;
     a->piano_bits = ORCA_PIANO_BITS_NONE;
     a->needs_remarking = true;
@@ -1878,6 +1916,7 @@ int main(int argc, char** argv) {
   int init_grid_dim_x = 57;
   Midi_mode midi_mode;
   midi_mode_init_null(&midi_mode);
+
   for (;;) {
     int c = getopt_long(argc, argv, "h", tui_options, NULL);
     if (c == -1)