hasufell/half-edge
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Be more fault tolerant for drawing normals

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Some open data structures are not yet supported
with vertex normals. Avoid infinite loop for those and
just draw what we got.
This commit is contained in:
hasufell 2014-05-17 14:55:46 +02:00
parent a677668418
commit acadb1161c
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GPG Key ID: 220CD1C5BDEED020
2 changed files with 17 additions and 3 deletions
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6
src/gl_draw.c
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@ -100,7 +100,10 @@ static void draw_normals(HE_obj const * const obj,
glBegin(GL_LINES); glBegin(GL_LINES);
for (uint32_t i = 0; i < obj->vc; i++) { for (uint32_t i = 0; i < obj->vc; i++) {
VEC_NORMAL(&(obj->vertices[i]), &vec); /* be fault tolerant here, so we don't just
* kill the whole thing, because the normals failed to draw */
if (!vec_normal(&(obj->vertices[i]), &vec))
break;
glVertex3f(obj->vertices[i].vec->x, glVertex3f(obj->vertices[i].vec->x,
obj->vertices[i].vec->y, obj->vertices[i].vec->y,
@ -108,7 +111,6 @@ static void draw_normals(HE_obj const * const obj,
glVertex3f(obj->vertices[i].vec->x + (vec.x * normals_scale_factor), glVertex3f(obj->vertices[i].vec->x + (vec.x * normals_scale_factor),
obj->vertices[i].vec->y + (vec.y * normals_scale_factor), obj->vertices[i].vec->y + (vec.y * normals_scale_factor),
obj->vertices[i].vec->z + (vec.z * normals_scale_factor)); obj->vertices[i].vec->z + (vec.z * normals_scale_factor));
} }
glEnd(); glEnd();
glPopMatrix(); glPopMatrix();

14
src/half_edge.c
View File

@ -72,6 +72,7 @@ static bool get_all_emanating_edges(HE_vert const * const vert,
uint32_t *ec_out) uint32_t *ec_out)
{ {
uint32_t ec = 0; /* edge count */ uint32_t ec = 0; /* edge count */
uint32_t max_edges = 500; /* good guess to avoid infinite loop */
HE_edge **edge_array = NULL; HE_edge **edge_array = NULL;
if (!edge_array_out || !vert || !ec_out) if (!edge_array_out || !vert || !ec_out)
@ -89,6 +90,9 @@ static bool get_all_emanating_edges(HE_vert const * const vert,
edge = edge->pair->next; edge = edge->pair->next;
ec++; ec++;
/* sanity check */
if (ec > max_edges)
goto loop_fail_cleanup;
} while (edge && edge != vert->edge); } while (edge && edge != vert->edge);
/* set out-pointers */ /* set out-pointers */
@ -96,6 +100,10 @@ static bool get_all_emanating_edges(HE_vert const * const vert,
*ec_out = ec; /* this is the real size, not the x[ec] value */ *ec_out = ec; /* this is the real size, not the x[ec] value */
return true; return true;
loop_fail_cleanup:
free(edge_array);
return false;
} }
@ -146,7 +154,11 @@ bool vec_normal(HE_vert const * const vert, vector *vec)
if (!vert || !vec) if (!vert || !vec)
return false; return false;
GET_ALL_EMANATING_EDGES(vert, &edge_array, &ec); /* fault tolerance if we didn't get any
* normal */
if (!get_all_emanating_edges(vert, &edge_array, &ec))
return false;
COPY_VECTOR(edge_array[0]->vert->vec, &he_base); COPY_VECTOR(edge_array[0]->vert->vec, &he_base);
SET_NULL_VECTOR(vec); /* set to null for later summation */ SET_NULL_VECTOR(vec); /* set to null for later summation */