From c584dd2298d23a366d0109e6443e698e0ee53370 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20Foucault?= Date: Thu, 9 Jul 2020 16:50:22 +0200 Subject: DRW: Put viewvecs calculation to view update This avoids code duplication between draw engines. --- source/blender/draw/intern/draw_manager_data.c | 46 ++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'source/blender') diff --git a/source/blender/draw/intern/draw_manager_data.c b/source/blender/draw/intern/draw_manager_data.c index 3d83b918757..41f442adec9 100644 --- a/source/blender/draw/intern/draw_manager_data.c +++ b/source/blender/draw/intern/draw_manager_data.c @@ -1656,6 +1656,52 @@ static void draw_view_matrix_state_update(DRWViewUboStorage *storage, mul_m4_m4m4(storage->persmat, winmat, viewmat); invert_m4_m4(storage->persinv, storage->persmat); + + const bool is_persp = (winmat[3][3] == 0.0f); + + /* Near clip distance. */ + storage->viewvecs[0][3] = (is_persp) ? -winmat[3][2] / (winmat[2][2] - 1.0f) : + -(winmat[3][2] + 1.0f) / winmat[2][2]; + + /* Far clip distance. */ + storage->viewvecs[1][3] = (is_persp) ? -winmat[3][2] / (winmat[2][2] + 1.0f) : + -(winmat[3][2] - 1.0f) / winmat[2][2]; + + /* view vectors for the corners of the view frustum. + * Can be used to recreate the world space position easily */ + float view_vecs[4][3] = { + {-1.0f, -1.0f, -1.0f}, + {1.0f, -1.0f, -1.0f}, + {-1.0f, 1.0f, -1.0f}, + {-1.0f, -1.0f, 1.0f}, + }; + + /* convert the view vectors to view space */ + for (int i = 0; i < 4; i++) { + mul_project_m4_v3(storage->wininv, view_vecs[i]); + /* normalized trick see: + * http://www.derschmale.com/2014/01/26/reconstructing-positions-from-the-depth-buffer */ + if (is_persp) { + /* Divide XY by Z. */ + mul_v2_fl(view_vecs[i], 1.0f / view_vecs[i][2]); + } + } + + /** + * If ortho : view_vecs[0] is the near-bottom-left corner of the frustum and + * view_vecs[1] is the vector going from the near-bottom-left corner to + * the far-top-right corner. + * If Persp : view_vecs[0].xy and view_vecs[1].xy are respectively the bottom-left corner + * when Z = 1, and top-left corner if Z = 1. + * view_vecs[0].z the near clip distance and view_vecs[1].z is the (signed) + * distance from the near plane to the far clip plane. + */ + copy_v3_v3(storage->viewvecs[0], view_vecs[0]); + + /* we need to store the differences */ + storage->viewvecs[1][0] = view_vecs[1][0] - view_vecs[0][0]; + storage->viewvecs[1][1] = view_vecs[2][1] - view_vecs[0][1]; + storage->viewvecs[1][2] = view_vecs[3][2] - view_vecs[0][2]; } /* Create a view with culling. */ -- cgit v1.2.3