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| author | Arman Uguray <armansito@google.com> | 2021-05-25 00:07:24 -0700 |
|---|---|---|
| committer | jeremyk-lunarg <jeremyk@lunarg.com> | 2021-06-03 14:51:11 -0600 |
| commit | 3ae088978f2107d79ac9a8eaec9ae0600f54f19f (patch) | |
| tree | d53fe651cec77493016c16fd59a5368d5ed85038 /cube/cube.c | |
| parent | 6149e30699b36901715d46a5cef8959625ef399b (diff) | |
| download | usermoji-3ae088978f2107d79ac9a8eaec9ae0600f54f19f.tar.xz | |
vkcube: Fix disturbed rotation after many iterations
vkcube computes the model matrix for the cube by repeatedly multiplying
a rotation matrix with it. After a sufficient number of iterations the
matrix becomes disturbed (likely due to numerical errors) and stops
being orthogonal and the cube vertices start scaling increasingly on the
XY plane.
* Orthonormalize the model matrix after each multiplication to prevent
the scaling.
* Use mat4x4_rotate_Y() instead of mat4x4_rotate() as it is less
verbose.
* Remove unused duplicate vkcube_vs_uniform struct.
Diffstat (limited to 'cube/cube.c')
| -rw-r--r-- | cube/cube.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/cube/cube.c b/cube/cube.c index 83022306..7f6effbd 100644 --- a/cube/cube.c +++ b/cube/cube.c @@ -882,7 +882,8 @@ void demo_update_data_buffer(struct demo *demo) { // Rotate around the Y axis mat4x4_dup(Model, demo->model_matrix); - mat4x4_rotate(demo->model_matrix, Model, 0.0f, 1.0f, 0.0f, (float)degreesToRadians(demo->spin_angle)); + mat4x4_rotate_Y(demo->model_matrix, Model, (float)degreesToRadians(demo->spin_angle)); + mat4x4_orthonormalize(demo->model_matrix, demo->model_matrix); mat4x4_mul(MVP, VP, demo->model_matrix); memcpy(demo->swapchain_image_resources[demo->current_buffer].uniform_memory_ptr, (const void *)&MVP[0][0], matrixSize); |