From d3969b617a9f27962f5bd8b1113763bf7134fc47 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Kristian=20H=C3=B8gsberg?= Date: Sat, 20 May 2006 17:30:28 -0400 Subject: [PATCH] Add fps counter, add comment about sqrt() approximation. --- akamaru.c | 170 ++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 106 insertions(+), 64 deletions(-) diff --git a/akamaru.c b/akamaru.c index fe14d20..14d0601 100644 --- a/akamaru.c +++ b/akamaru.c @@ -20,6 +20,7 @@ #include #include #include +#include #include const double ground_friction = 0.1, ground_level = 400; @@ -206,13 +207,13 @@ model_init_curtain (Model *model) static void model_init_grid (Model *model) { - const int num_ropes = 4; - const int num_rope_objects = 4; + const int num_ropes = 10; + const int num_rope_objects = 10; const int num_objects = num_ropes * num_rope_objects; const int num_strings = num_ropes * (num_rope_objects - 1) + (num_ropes - 1) * num_rope_objects; - const int string_length = 30; - const int rope_offset = 30; + const int string_length = 10; + const int rope_offset = 10; double x, y; int i, j, index, string_index; @@ -312,6 +313,29 @@ model_integrate (Model *model, double step) } } +/* The square root in the distance computation for the string and + * stick constraints can be aproximated using Newton: + * + * distance = + * (model->sticks[i].length + + * (dx * dx + dy * dy) / model->sticks[i].length) / 2; + * + * This works really well, since the constraints aren't typically + * violated much. Thus, the distance is really close to the stick + * length, which then makes a good initial guess. However, the + * approximation seems to be slower that just calling sqrt()... + */ + +static inline double +estimate_distance (double dx, double dy, double r) +{ +#ifdef APPROXIMATE_SQUARE_ROOTS + return (r + (dx * dx + dy * dy) / r) / 2; +#else + return sqrt (dx * dx + dy * dy); +#endif +} + static void model_constrain (Model *model, double step) { @@ -376,7 +400,7 @@ model_constrain (Model *model, double step) y = model->strings[i].a->position.y; dx = model->strings[i].b->position.x - x; dy = model->strings[i].b->position.y - y; - distance = sqrt (dx * dx + dy * dy); + distance = estimate_distance (dx, dy, model->strings[i].length); if (distance < model->strings[i].length) continue; fraction = (distance - model->strings[i].length) / distance / 2; @@ -386,36 +410,19 @@ model_constrain (Model *model, double step) model->strings[i].b->position.y = y + dy * (1 - fraction); } -#if 1 /* Stick constraints. */ for (i = 0; i < model->num_sticks; i++) { x = model->sticks[i].a->position.x; y = model->sticks[i].a->position.y; dx = model->sticks[i].b->position.x - x; dy = model->sticks[i].b->position.y - y; - distance = sqrt (dx * dx + dy * dy); + distance = estimate_distance (dx, dy, model->sticks[i].length); fraction = (distance - model->sticks[i].length) / distance / 2; model->sticks[i].a->position.x = x + dx * fraction; model->sticks[i].a->position.y = y + dy * fraction; model->sticks[i].b->position.x = x + dx * (1 - fraction); model->sticks[i].b->position.y = y + dy * (1 - fraction); } -#else - /* Stick constraints, without square roots. */ - squared = stick_length * stick_length; - for (i = 0; i < model->num_objects - 1; i++) { - j = i + 1; - x = model->objects[i].position.x; - y = model->objects[i].position.y; - dx = model->objects[j].position.x - x; - dy = model->objects[j].position.y - y; - fraction = squared / (dx * dx + dy * dy + squared) - 0.5; - model->objects[i].position.x = x + dx * fraction; - model->objects[i].position.y = y + dy * fraction; - model->objects[j].position.x = x + dx * (1 - fraction); - model->objects[j].position.y = y + dy * (1 - fraction); - } -#endif } static void @@ -426,7 +433,7 @@ model_step (Model *model, double delta_t) model_accumulate_forces (model); model_integrate (model, delta_t); - for (i = 0; i < 35; i++) + for (i = 0; i < 100; i++) model_constrain (model, delta_t); model->theta += delta_t; @@ -578,12 +585,22 @@ static Color red = { 1, 0, 0 }; static Color black = { 0, 0, 0 }; static Color white = { 1, 1, 1 }; +typedef struct _Closure Closure; +struct _Closure { + GtkWidget *drawing_area; + GtkWidget *fps_label; + Model *model; + int frame_count; + int i; + struct timeval start; +}; + static gboolean expose_event (GtkWidget *widget, GdkEventExpose *event, gpointer data) { - Model *model = data; + Closure *closure = data; cairo_t *cr; cr = gdk_cairo_create (widget->window); @@ -591,11 +608,11 @@ expose_event (GtkWidget *widget, cairo_set_source_rgb (cr, 1, 1, 1); cairo_paint (cr); - draw_constraints (cr, model, &red); - draw_sticks (cr, model, &black); - draw_strings (cr, model, &green); - draw_offsets (cr, model, &blue); - draw_objects (cr, model, &white); + draw_constraints (cr, closure->model, &red); + draw_sticks (cr, closure->model, &black); + draw_strings (cr, closure->model, &green); + draw_offsets (cr, closure->model, &blue); + draw_objects (cr, closure->model, &white); cairo_destroy (cr); @@ -607,14 +624,15 @@ button_press_event (GtkWidget *widget, GdkEventButton *event, gpointer data) { - Model *model = data; + Closure *closure = data; if (event->button != 1) return TRUE; - model->anchor_position.x = event->x; - model->anchor_position.y = event->y; - model->anchor_object = model_find_nearest (model, event->x, event->y); + closure->model->anchor_position.x = event->x; + closure->model->anchor_position.y = event->y; + closure->model->anchor_object = model_find_nearest (closure->model, + event->x, event->y); return TRUE; } @@ -624,12 +642,12 @@ button_release_event (GtkWidget *widget, GdkEventButton *event, gpointer data) { - Model *model = data; + Closure *closure = data; if ((event->state & GDK_BUTTON1_MASK) == 0) return TRUE; - model->anchor_object = NULL; + closure->model->anchor_object = NULL; return TRUE; } @@ -639,14 +657,14 @@ motion_notify_event (GtkWidget *widget, GdkEventMotion *event, gpointer data) { - Model *model = data; + Closure *closure = data; int x, y; GdkModifierType state; gdk_window_get_pointer (event->window, &x, &y, &state); - model->anchor_position.x = x + 0.5; - model->anchor_position.y = y + 0.5; + closure->model->anchor_position.x = x + 0.5; + closure->model->anchor_position.y = y + 0.5; return TRUE; } @@ -656,7 +674,7 @@ typedef void (*ModelInitFunc) (Model *model); static void model_changed (GtkComboBox *combo, gpointer user_data) { - Model *model = user_data; + Closure *closure = user_data; GtkTreeIter iter; GtkTreeModel *tree_model; ModelInitFunc init; @@ -668,8 +686,8 @@ model_changed (GtkComboBox *combo, gpointer user_data) gtk_tree_model_get (tree_model, &iter, 0, &name, 1, &init, -1); - model_fini (model); - (*init) (model); + model_fini (closure->model); + (*init) (closure->model); } static GtkTreeModel * @@ -702,7 +720,7 @@ create_model_store (void) } static GtkWidget * -create_model_combo (Model *model) +create_model_combo (Closure *closure) { GtkWidget *hbox; GtkWidget *combo, *label; @@ -728,13 +746,18 @@ create_model_combo (Model *model) gtk_label_set_mnemonic_widget (GTK_LABEL (label), combo); gtk_box_pack_start (GTK_BOX (hbox), combo, FALSE, FALSE, 0); g_signal_connect (combo, "changed", - G_CALLBACK (model_changed), model); + G_CALLBACK (model_changed), closure); + + label = gtk_label_new ("Frames per second: 0"); + gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0); + + closure->fps_label = label; return hbox; } -static GtkWidget * -create_window (Model *model) +static void +create_window (Closure *closure) { GtkWidget *window; GtkWidget *frame; @@ -743,7 +766,7 @@ create_window (Model *model) GtkWidget *model_combo; window = gtk_window_new (GTK_WINDOW_TOPLEVEL); - gtk_window_set_title (GTK_WINDOW (window), "Drawing Area"); + gtk_window_set_title (GTK_WINDOW (window), "Akamaru"); g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), &window); @@ -771,16 +794,16 @@ create_window (Model *model) /* Signals used to handle backing pixmap */ g_signal_connect (da, "expose_event", - G_CALLBACK (expose_event), model); + G_CALLBACK (expose_event), closure); /* Event signals */ g_signal_connect (da, "motion_notify_event", - G_CALLBACK (motion_notify_event), model); + G_CALLBACK (motion_notify_event), closure); g_signal_connect (da, "button_press_event", - G_CALLBACK (button_press_event), model); + G_CALLBACK (button_press_event), closure); g_signal_connect (da, "button_release_event", - G_CALLBACK (button_release_event), model); + G_CALLBACK (button_release_event), closure); /* Ask to receive events the drawing area doesn't normally * subscribe to @@ -792,32 +815,49 @@ create_window (Model *model) | GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK); - model_combo = create_model_combo (model); + model_combo = create_model_combo (closure); gtk_box_pack_start (GTK_BOX (vbox), model_combo, FALSE, FALSE, 0); - return da; + closure->drawing_area = da; } -typedef struct _Closure Closure; -struct _Closure { - GtkWidget *drawing_area; - Model *model; - int i; -}; - static gint timeout_callback (gpointer data) { Closure *closure = data; int i; - for (i = 0; i < 3; i++) - model_step (closure->model, 0.5); + model_step (closure->model, 1); closure->i++; if (closure->i == 1) { gtk_widget_queue_draw (closure->drawing_area); closure->i = 0; + closure->frame_count++; + } + + if (closure->frame_count == 200) { + struct timeval end, elapsed; + double total; + char text[50]; + + closure->frame_count = 0; + gettimeofday (&end, NULL); + if (closure->start.tv_usec > end.tv_usec) { + end.tv_usec += 1000000; + end.tv_sec--; + } + + elapsed.tv_usec = end.tv_usec - closure->start.tv_usec; + elapsed.tv_sec = end.tv_sec - closure->start.tv_sec; + + total = elapsed.tv_sec + ((double) elapsed.tv_usec / 1e6); + if (total < 0) { + total = 0; + } + closure->start = end; + snprintf (text, sizeof text, "Frames per second: %.2f", 200 / total); + gtk_label_set_text (GTK_LABEL (closure->fps_label), text); } return TRUE; @@ -831,11 +871,13 @@ main (int argc, char *argv[]) gtk_init (&argc, &argv); model_init_rope (&model); - closure.drawing_area = create_window (&model); + create_window (&closure); closure.i = 0; gtk_widget_show_all (gtk_widget_get_toplevel (closure.drawing_area)); closure.model = &model; - g_timeout_add (100, timeout_callback, &closure); + closure.frame_count = 0; + gettimeofday (&closure.start, NULL); + g_timeout_add (40, timeout_callback, &closure); gtk_main (); return 0; -- 2.43.0