void idle(void) { if (deltaSinceDraw) { x += deltaSinceDraw; clamp_x(); draw(); deltaSinceDraw = 0; } }
/* ARGSUSED */ void button(int button, int state, int xpos, int ypos) { if (state == GLUT_DOWN) { mouseOriginX = xpos; deltaSinceDraw = 0; glutIdleFunc(idle); return; } if (!moveCalled) { if (button == GLUT_MIDDLE_BUTTON) x = 1.; else x = (float)xpos / ((float)w / 2.); clamp_x(); deltaSinceDraw = 100000.; } moveCalled = 0; if (deltaSinceDraw) draw(); printf("x = %f\n", x); glutIdleFunc(NULL); }
static void paint_large_line (GooDemoLargeLine *line, cairo_t *cr, const GooCanvasBounds *bounds, gdouble line_width, gdouble x1, gdouble y1, gdouble x2, gdouble y2) { GooCanvasItem *item = (GooCanvasItem*) line; GooCanvasItemSimple *simple = (GooCanvasItemSimple*) line; GooCanvas *canvas = simple->canvas; GooCanvasBounds tmp_bounds = *bounds; gdouble point1[2], point2[2], *p1, *p2; point1[0] = x1; point1[1] = y1; point2[0] = x2; point2[1] = y2; /* Transform the coordinates to the canvas device space, so we can clamp the line to the bounds to be painted. */ goo_canvas_convert_from_item_space (canvas, item, &point1[0], &point1[1]); goo_canvas_convert_from_item_space (canvas, item, &point2[0], &point2[1]); /* Extend the bounds a bit to account for the line width. */ tmp_bounds.x1 -= line_width; tmp_bounds.y1 -= line_width; tmp_bounds.x2 += line_width; tmp_bounds.y2 += line_width; /* Make p1 the left-most point. */ if (point1[0] < point2[0]) { p1 = point1; p2 = point2; } else { p1 = point2; p2 = point1; } /* Just return if the line is completely outside the bounds horizontally. */ if (p2[0] < tmp_bounds.x1 || p1[0] > tmp_bounds.x2) return; /* Clamp each x coordinate to the bounds. */ if (p1[0] < tmp_bounds.x1) clamp_x (p1, p2, tmp_bounds.x1); if (p2[0] > tmp_bounds.x2) clamp_x (p2, p1, tmp_bounds.x2); /* Now make p1 the top-most point. */ if (point1[1] < point2[1]) { p1 = point1; p2 = point2; } else { p1 = point2; p2 = point1; } /* Just return if the line is completely outside the bounds vertically. */ if (p2[1] < tmp_bounds.y1 || p1[1] > tmp_bounds.y2) return; /* Clamp each y coordinate to the bounds. */ if (p1[1] < tmp_bounds.y1) clamp_y (p1, p2, tmp_bounds.y1); if (p2[1] > tmp_bounds.y2) clamp_y (p2, p1, tmp_bounds.y2); /* Convert back to item space. */ goo_canvas_convert_to_item_space (canvas, item, &point1[0], &point1[1]); goo_canvas_convert_to_item_space (canvas, item, &point2[0], &point2[1]); /* Draw the line. */ cairo_move_to (cr, point1[0], point1[1]); cairo_line_to (cr, point2[0], point2[1]); cairo_stroke (cr); }