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Fix rBb31ebd8c5c55: the asymmetric furstrum algorithm was still incorrect. 

Although somewhat less micro efficient, I decided to separate the `viewinv` matrix to calculate the world position separately.
This makes it easier to understand the code.
This commit is contained in:
Germano Cavalcante 2018-04-16 10:40:46 -03:00
parent 57c651d248
commit 86abc4da10
1 changed files with 34 additions and 75 deletions
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109
source/blender/draw/intern/draw_manager_exec.c
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@ -384,100 +384,55 @@ void DRW_state_clip_planes_reset(void)
/** \name Clipping (DRW_clipping)
* \{ */
/* Extract the 8 corners (world space).
/* Extract the 8 corners from a Projection Matrix.
* Although less accurate, this solution can be simplified as follows:
* BKE_boundbox_init_from_minmax(&bbox, (const float[3]){-1.0f, -1.0f, -1.0f}, (const float[3]){1.0f, 1.0f, 1.0f});
* for (int i = 0; i < 8; i++) {mul_project_m4_v3(viewprojinv, bbox.vec[i]);}
* for (int i = 0; i < 8; i++) {mul_project_m4_v3(projinv, bbox.vec[i]);}
*/
static void draw_frustum_boundbox_calc(
const float (*projmat)[4], const float (*viewinv)[4], BoundBox *r_bbox)
static void draw_frustum_boundbox_calc(const float(*projmat)[4], BoundBox *r_bbox)
{
float screenvecs[3][3], loc[3], near, far, w_half, h_half;
float near, far, left, right, bottom, top;
bool is_persp = projmat[3][3] == 0.0f;
copy_m3_m4(screenvecs, viewinv);
copy_v3_v3(loc, viewinv[3]);
/* get the values of the minimum and maximum clipping planes distances
* and half the width and height of the nearplane rectangle. */
if (is_persp) {
near = projmat[3][2] / (projmat[2][2] - 1.0f);
far = projmat[3][2] / (projmat[2][2] + 1.0f);
w_half = near / projmat[0][0];
h_half = near / projmat[1][1];
float w_half = near / projmat[0][0];
float h_half = near / projmat[1][1];
left = projmat[2][0] - w_half;
right = projmat[2][0] + w_half;
bottom = projmat[2][1] - h_half;
top = projmat[2][1] + h_half;
}
else {
near = (projmat[3][2] + 1.0f) / projmat[2][2];
far = (projmat[3][2] - 1.0f) / projmat[2][2];
w_half = 1.0f / projmat[0][0];
h_half = 1.0f / projmat[1][1];
left = (-1.0f - projmat[3][0]) / projmat[0][0];
right = (1.0f - projmat[3][0]) / projmat[0][0];
bottom = (-1.0f - projmat[3][1]) / projmat[1][1];
top = (1.0f - projmat[3][1]) / projmat[1][1];
}
/* With vectors aligned to the screen, reconstruct
* the near plane from the dimensions obtained earlier. */
float mid[3], hor[3], ver[3];
mul_v3_v3fl(hor, screenvecs[0], w_half);
mul_v3_v3fl(ver, screenvecs[1], h_half);
madd_v3_v3v3fl(mid, loc, screenvecs[2], -near);
/* The case below is for non-symmetric frustum. */
if (is_persp) {
madd_v3_v3fl(mid, hor, projmat[2][0]);
madd_v3_v3fl(mid, ver, projmat[2][1]);
}
else {
madd_v3_v3fl(mid, hor, -projmat[3][0]);
madd_v3_v3fl(mid, ver, -projmat[3][1]);
}
r_bbox->vec[0][0] = mid[0] - ver[0] - hor[0];
r_bbox->vec[0][1] = mid[1] - ver[1] - hor[1];
r_bbox->vec[0][2] = mid[2] - ver[2] - hor[2];
r_bbox->vec[3][0] = mid[0] + ver[0] - hor[0];
r_bbox->vec[3][1] = mid[1] + ver[1] - hor[1];
r_bbox->vec[3][2] = mid[2] + ver[2] - hor[2];
r_bbox->vec[7][0] = mid[0] + ver[0] + hor[0];
r_bbox->vec[7][1] = mid[1] + ver[1] + hor[1];
r_bbox->vec[7][2] = mid[2] + ver[2] + hor[2];
r_bbox->vec[4][0] = mid[0] - ver[0] + hor[0];
r_bbox->vec[4][1] = mid[1] - ver[1] + hor[1];
r_bbox->vec[4][2] = mid[2] - ver[2] + hor[2];
r_bbox->vec[0][2] = r_bbox->vec[3][2] = r_bbox->vec[7][2] = r_bbox->vec[4][2] = -near;
r_bbox->vec[1][2] = r_bbox->vec[2][2] = r_bbox->vec[6][2] = r_bbox->vec[5][2] = -far;
r_bbox->vec[0][0] = r_bbox->vec[3][0] = left;
r_bbox->vec[4][0] = r_bbox->vec[7][0] = right;
r_bbox->vec[0][1] = r_bbox->vec[4][1] = bottom;
r_bbox->vec[7][1] = r_bbox->vec[3][1] = top;
/* Get the coordinates of the far plane. */
if (is_persp) {
float sca_far = far / near;
mid[0] = mid[0] + (mid[0] - loc[0]) * sca_far;
mid[1] = mid[1] + (mid[1] - loc[1]) * sca_far;
mid[2] = mid[2] + (mid[2] - loc[2]) * sca_far;
mul_v3_fl(hor, sca_far);
mul_v3_fl(ver, sca_far);
}
else {
madd_v3_v3v3fl(mid, loc, screenvecs[2], -far);
/* Non-symmetric frustum. */
madd_v3_v3fl(mid, hor, -projmat[3][0]);
madd_v3_v3fl(mid, ver, -projmat[3][1]);
left *= sca_far;
bottom *= sca_far;
right *= sca_far;
top *= sca_far;
}
r_bbox->vec[1][0] = mid[0] - ver[0] - hor[0];
r_bbox->vec[1][1] = mid[1] - ver[1] - hor[1];
r_bbox->vec[1][2] = mid[2] - ver[2] - hor[2];
r_bbox->vec[2][0] = mid[0] + ver[0] - hor[0];
r_bbox->vec[2][1] = mid[1] + ver[1] - hor[1];
r_bbox->vec[2][2] = mid[2] + ver[2] - hor[2];
r_bbox->vec[6][0] = mid[0] + ver[0] + hor[0];
r_bbox->vec[6][1] = mid[1] + ver[1] + hor[1];
r_bbox->vec[6][2] = mid[2] + ver[2] + hor[2];
r_bbox->vec[5][0] = mid[0] - ver[0] + hor[0];
r_bbox->vec[5][1] = mid[1] - ver[1] + hor[1];
r_bbox->vec[5][2] = mid[2] - ver[2] + hor[2];
r_bbox->vec[1][0] = r_bbox->vec[2][0] = left;
r_bbox->vec[6][0] = r_bbox->vec[5][0] = right;
r_bbox->vec[1][1] = r_bbox->vec[5][1] = bottom;
r_bbox->vec[2][1] = r_bbox->vec[6][1] = top;
}
static void draw_clipping_setup_from_view(void)
@ -495,11 +450,15 @@ static void draw_clipping_setup_from_view(void)
#if 0 /* It has accuracy problems. */
BKE_boundbox_init_from_minmax(&bbox, (const float[3]){-1.0f, -1.0f, -1.0f}, (const float[3]){1.0f, 1.0f, 1.0f});
for (int i = 0; i < 8; i++) {
mul_project_m4_v3(DST.view_data.matstate.mat[DRW_MAT_PERSINV], bbox.vec[i]);
mul_project_m4_v3(projinv, bbox.vec[i]);
}
#else
draw_frustum_boundbox_calc(projmat, viewinv, &bbox);
draw_frustum_boundbox_calc(projmat, &bbox);
#endif
/* Transform into world space. */
for (int i = 0; i < 8; i++) {
mul_m4_v3(viewinv, bbox.vec[i]);
}
/* Compute clip planes using the world space frustum corners. */
for (int p = 0; p < 6; p++) {