32 lines
1021 B
C++
32 lines
1021 B
C++
#include "harness.hpp"
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#include <plot/math/transform.hpp>
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using plot::Transform;
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PLOT_TEST(linear_round_trip) {
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Transform t{2.0, 10.0, 3.0, -1.0, false, false};
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PLOT_CHECK_NEAR(t.to_screen_x(0.0), 10.0, 1e-12);
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PLOT_CHECK_NEAR(t.to_screen_x(5.0), 20.0, 1e-12);
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PLOT_CHECK_NEAR(t.to_data_x(20.0), 5.0, 1e-12);
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PLOT_CHECK_NEAR(t.to_data_y(t.to_screen_y(7.5)), 7.5, 1e-12);
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}
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PLOT_TEST(log_x_round_trip) {
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Transform t{100.0, 0.0, 1.0, 0.0, true, false};
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PLOT_CHECK_NEAR(t.to_screen_x(1.0), 0.0, 1e-12);
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PLOT_CHECK_NEAR(t.to_screen_x(10.0), 100.0, 1e-12);
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PLOT_CHECK_NEAR(t.to_data_x(100.0), 10.0, 1e-9);
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}
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PLOT_TEST(zoom_anchor_is_invariant) {
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// Anchoring a zoom at a data coordinate must leave that coordinate's screen
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// position unchanged.
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Transform t{1.0, 0.0, 1.0, 0.0, false, false};
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const double anchor_data = 3.25;
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const double before = t.to_screen_x(anchor_data);
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t.sx *= 4.0;
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t.tx = before - anchor_data * t.sx;
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PLOT_CHECK_NEAR(t.to_screen_x(anchor_data), before, 1e-12);
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}
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