40 lines
845 B
C
40 lines
845 B
C
#include <math.h>
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#include <gtk/gtk.h>
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#include "gravity.h"
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#include "game.h"
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double g_y = 20;
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double g_x = 0;
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static int gravity_vector_countdown = 0;
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static int gravity_vector_init = 300;
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void gravity_draw (cairo_t * cr) {
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if (gravity_vector_countdown != 0) {
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cairo_save(cr);
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cairo_new_path(cr);
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cairo_move_to(cr, width/2, height/2);
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cairo_line_to(cr, width/2 + g_x, height/2 + g_y);
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cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);
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cairo_set_line_width(cr, 1.0);
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cairo_stroke(cr);
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cairo_arc(cr, width/2 + g_x, height/2 + g_y, 3, 0, 2*M_PI);
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cairo_fill(cr);
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if (gravity_vector_countdown > 0)
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--gravity_vector_countdown;
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cairo_restore(cr);
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}
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}
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void gravity_show () {
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gravity_vector_countdown = gravity_vector_init;
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};
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void gravity_change (double dx, double dy) {
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g_x += dx;
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g_y += dy;
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gravity_show ();
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};
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