The open source OpenXR runtime
a/util: Fix edge cases in Moses's distortion method
Before this, we read out of bounds at the bottom of the display. Unsure why nothing but Valgrind caught it.
authored by
Moses Turner
and committed by
Moses Turner
dcbdcede
bb752819
+26
-6
+26
-6
src/xrt/auxiliary/util/u_distortion_mesh.c
+26
-6
src/xrt/auxiliary/util/u_distortion_mesh.c
···
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float v_index_frac = (v * v_edge_num) - v_index_int;
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// Imagine this like a ray coming out of your eye with x, y coordinate bearing and z coordinate -1.0f
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struct xrt_vec2 bearing;
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struct xrt_vec2 bearing = {0};
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int stride = values->num_grid_points_u;
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float eps = 0.000001;
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if (u_index_frac > 0.000001 || v_index_frac > 0.000001) {
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struct xrt_vec2 *grid = values->grid[view];
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int topleft_i = (v_index_int * stride) + u_index_int;
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int topright_i = (v_index_int * stride) + u_index_int + 1;
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int bottomleft_i = ((v_index_int + 1) * stride) + u_index_int;
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int bottomright_i = ((v_index_int + 1) * stride) + u_index_int + 1;
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if (u_index_frac > eps && v_index_frac > eps) {
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// Usual case - we're in the middle of a cell
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// {top,bottom}-{left,right} notation might be inaccurate. The code *works* right now but don't take its
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// word when reading
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struct xrt_vec2 topleft = values->grid[view][(v_index_int * stride) + u_index_int];
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struct xrt_vec2 topright = values->grid[view][(v_index_int * stride) + u_index_int + 1];
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struct xrt_vec2 bottomleft = values->grid[view][((v_index_int + 1) * stride) + u_index_int];
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struct xrt_vec2 bottomright = values->grid[view][((v_index_int + 1) * stride) + u_index_int + 1];
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struct xrt_vec2 topleft = grid[topleft_i];
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struct xrt_vec2 topright = grid[topright_i];
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struct xrt_vec2 bottomleft = grid[bottomleft_i];
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struct xrt_vec2 bottomright = grid[bottomright_i];
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struct xrt_vec2 left_point_on_line_segment = m_vec2_lerp(topleft, bottomleft, v_index_frac);
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struct xrt_vec2 right_point_on_line_segment = m_vec2_lerp(topright, bottomright, v_index_frac);
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bearing = m_vec2_lerp(left_point_on_line_segment, right_point_on_line_segment, u_index_frac);
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} else if (v_index_frac > eps) {
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// We're on a vertical edge
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struct xrt_vec2 top = values->grid[view][topleft_i];
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struct xrt_vec2 bottom = values->grid[view][bottomleft_i];
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bearing = m_vec2_lerp(top, bottom, v_index_frac);
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} else if (u_index_frac > eps) {
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// We're on a horizontal edge
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struct xrt_vec2 left = values->grid[view][topleft_i];
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struct xrt_vec2 right = values->grid[view][topright_i];
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bearing = m_vec2_lerp(left, right, u_index_frac);
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} else {
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int acc_idx = (v_index_int * stride) + u_index_int;
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bearing = values->grid[view][acc_idx];