Files
test2/source/blender/geometry/intern/mesh_primitive_cuboid.cc
Hans Goudey 2c43a9eed9 Cleanup: Move BKE_mesh_calc_edges to bke namespace
Also use reference for mesh argument, and move edges calculation
from legacy faces to "legacy" file.
2023-12-20 20:47:10 -05:00

407 lines
13 KiB
C++

/* SPDX-FileCopyrightText: 2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#include "BKE_attribute.hh"
#include "BKE_mesh.hh"
#include "GEO_mesh_primitive_cuboid.hh"
namespace blender::geometry {
struct CuboidConfig {
float3 size;
int verts_x;
int verts_y;
int verts_z;
int edges_x;
int edges_y;
int edges_z;
int vertex_count;
int face_count;
int loop_count;
CuboidConfig(float3 size, int verts_x, int verts_y, int verts_z)
: size(size),
verts_x(verts_x),
verts_y(verts_y),
verts_z(verts_z),
edges_x(verts_x - 1),
edges_y(verts_y - 1),
edges_z(verts_z - 1)
{
BLI_assert(edges_x > 0 && edges_y > 0 && edges_z > 0);
this->vertex_count = this->get_vertex_count();
this->face_count = this->get_face_count();
this->loop_count = this->face_count * 4;
}
private:
int get_vertex_count()
{
const int inner_position_count = (verts_x - 2) * (verts_y - 2) * (verts_z - 2);
return verts_x * verts_y * verts_z - inner_position_count;
}
int get_face_count()
{
return 2 * (edges_x * edges_y + edges_y * edges_z + edges_z * edges_x);
}
};
static void calculate_positions(const CuboidConfig &config, MutableSpan<float3> positions)
{
const float z_bottom = -config.size.z / 2.0f;
const float z_delta = config.size.z / config.edges_z;
const float x_left = -config.size.x / 2.0f;
const float x_delta = config.size.x / config.edges_x;
const float y_front = -config.size.y / 2.0f;
const float y_delta = config.size.y / config.edges_y;
int vert_index = 0;
for (const int z : IndexRange(config.verts_z)) {
if (ELEM(z, 0, config.edges_z)) {
/* Fill bottom and top. */
const float z_pos = z_bottom + z_delta * z;
for (const int y : IndexRange(config.verts_y)) {
const float y_pos = y_front + y_delta * y;
for (const int x : IndexRange(config.verts_x)) {
const float x_pos = x_left + x_delta * x;
positions[vert_index++] = float3(x_pos, y_pos, z_pos);
}
}
}
else {
for (const int y : IndexRange(config.verts_y)) {
if (ELEM(y, 0, config.edges_y)) {
/* Fill y-sides. */
const float y_pos = y_front + y_delta * y;
const float z_pos = z_bottom + z_delta * z;
for (const int x : IndexRange(config.verts_x)) {
const float x_pos = x_left + x_delta * x;
positions[vert_index++] = float3(x_pos, y_pos, z_pos);
}
}
else {
/* Fill x-sides. */
const float x_pos = x_left;
const float y_pos = y_front + y_delta * y;
const float z_pos = z_bottom + z_delta * z;
positions[vert_index++] = float3(x_pos, y_pos, z_pos);
const float x_pos2 = x_left + x_delta * config.edges_x;
positions[vert_index++] = float3(x_pos2, y_pos, z_pos);
}
}
}
}
}
/* vert_1 = bottom left, vert_2 = bottom right, vert_3 = top right, vert_4 = top left.
* Hence they are passed as 1,4,3,2 when calculating faces clockwise, and 1,2,3,4 for
* anti-clockwise.
*/
static void define_quad(MutableSpan<int> corner_verts,
const int loop_index,
const int vert_1,
const int vert_2,
const int vert_3,
const int vert_4)
{
corner_verts[loop_index] = vert_1;
corner_verts[loop_index + 1] = vert_2;
corner_verts[loop_index + 2] = vert_3;
corner_verts[loop_index + 3] = vert_4;
}
static void calculate_corner_verts(const CuboidConfig &config, MutableSpan<int> corner_verts)
{
int loop_index = 0;
/* Number of vertices in an XY cross-section of the cube (barring top and bottom faces). */
const int xy_cross_section_vert_count = config.verts_x * config.verts_y -
(config.verts_x - 2) * (config.verts_y - 2);
/* Calculate faces for Bottom faces. */
int vert_1_start = 0;
for ([[maybe_unused]] const int y : IndexRange(config.edges_y)) {
for (const int x : IndexRange(config.edges_x)) {
const int vert_1 = vert_1_start + x;
const int vert_2 = vert_1_start + config.verts_x + x;
const int vert_3 = vert_2 + 1;
const int vert_4 = vert_1 + 1;
define_quad(corner_verts, loop_index, vert_1, vert_2, vert_3, vert_4);
loop_index += 4;
}
vert_1_start += config.verts_x;
}
/* Calculate faces for Front faces. */
vert_1_start = 0;
int vert_2_start = config.verts_x * config.verts_y;
for ([[maybe_unused]] const int z : IndexRange(config.edges_z)) {
for (const int x : IndexRange(config.edges_x)) {
define_quad(corner_verts,
loop_index,
vert_1_start + x,
vert_1_start + x + 1,
vert_2_start + x + 1,
vert_2_start + x);
loop_index += 4;
}
vert_1_start = vert_2_start;
vert_2_start += config.verts_x * config.verts_y - (config.verts_x - 2) * (config.verts_y - 2);
}
/* Calculate faces for Top faces. */
vert_1_start = config.verts_x * config.verts_y +
(config.verts_z - 2) * (config.verts_x * config.verts_y -
(config.verts_x - 2) * (config.verts_y - 2));
vert_2_start = vert_1_start + config.verts_x;
for ([[maybe_unused]] const int y : IndexRange(config.edges_y)) {
for (const int x : IndexRange(config.edges_x)) {
define_quad(corner_verts,
loop_index,
vert_1_start + x,
vert_1_start + x + 1,
vert_2_start + x + 1,
vert_2_start + x);
loop_index += 4;
}
vert_2_start += config.verts_x;
vert_1_start += config.verts_x;
}
/* Calculate faces for Back faces. */
vert_1_start = config.verts_x * config.edges_y;
vert_2_start = vert_1_start + xy_cross_section_vert_count;
for (const int z : IndexRange(config.edges_z)) {
if (z == (config.edges_z - 1)) {
vert_2_start += (config.verts_x - 2) * (config.verts_y - 2);
}
for (const int x : IndexRange(config.edges_x)) {
define_quad(corner_verts,
loop_index,
vert_1_start + x,
vert_2_start + x,
vert_2_start + x + 1,
vert_1_start + x + 1);
loop_index += 4;
}
vert_2_start += xy_cross_section_vert_count;
vert_1_start += xy_cross_section_vert_count;
}
/* Calculate faces for Left faces. */
vert_1_start = 0;
vert_2_start = config.verts_x * config.verts_y;
for (const int z : IndexRange(config.edges_z)) {
for (const int y : IndexRange(config.edges_y)) {
int vert_1;
int vert_2;
int vert_3;
int vert_4;
if (z == 0 || y == 0) {
vert_1 = vert_1_start + config.verts_x * y;
vert_4 = vert_1 + config.verts_x;
}
else {
vert_1 = vert_1_start + 2 * y;
vert_1 += config.verts_x - 2;
vert_4 = vert_1 + 2;
}
if (y == 0 || z == (config.edges_z - 1)) {
vert_2 = vert_2_start + config.verts_x * y;
vert_3 = vert_2 + config.verts_x;
}
else {
vert_2 = vert_2_start + 2 * y;
vert_2 += config.verts_x - 2;
vert_3 = vert_2 + 2;
}
define_quad(corner_verts, loop_index, vert_1, vert_2, vert_3, vert_4);
loop_index += 4;
}
if (z == 0) {
vert_1_start += config.verts_x * config.verts_y;
}
else {
vert_1_start += xy_cross_section_vert_count;
}
vert_2_start += xy_cross_section_vert_count;
}
/* Calculate faces for Right faces. */
vert_1_start = config.edges_x;
vert_2_start = vert_1_start + config.verts_x * config.verts_y;
for (const int z : IndexRange(config.edges_z)) {
for (const int y : IndexRange(config.edges_y)) {
int vert_1 = vert_1_start;
int vert_2 = vert_2_start;
int vert_3 = vert_2_start + 2;
int vert_4 = vert_1 + config.verts_x;
if (z == 0) {
vert_1 = vert_1_start + config.verts_x * y;
vert_4 = vert_1 + config.verts_x;
}
else {
vert_1 = vert_1_start + 2 * y;
vert_4 = vert_1 + 2;
}
if (z == (config.edges_z - 1)) {
vert_2 = vert_2_start + config.verts_x * y;
vert_3 = vert_2 + config.verts_x;
}
else {
vert_2 = vert_2_start + 2 * y;
vert_3 = vert_2 + 2;
}
if (y == (config.edges_y - 1)) {
vert_3 = vert_2 + config.verts_x;
vert_4 = vert_1 + config.verts_x;
}
define_quad(corner_verts, loop_index, vert_1, vert_4, vert_3, vert_2);
loop_index += 4;
}
if (z == 0) {
vert_1_start += config.verts_x * config.verts_y;
}
else {
vert_1_start += xy_cross_section_vert_count;
}
vert_2_start += xy_cross_section_vert_count;
}
}
static void calculate_uvs(const CuboidConfig &config, Mesh *mesh, const bke::AttributeIDRef &uv_id)
{
bke::MutableAttributeAccessor attributes = mesh->attributes_for_write();
bke::SpanAttributeWriter uv_attribute = attributes.lookup_or_add_for_write_only_span<float2>(
uv_id, bke::AttrDomain::Corner);
MutableSpan<float2> uvs = uv_attribute.span;
int loop_index = 0;
const float x_delta = 0.25f / float(config.edges_x);
const float y_delta = 0.25f / float(config.edges_y);
const float z_delta = 0.25f / float(config.edges_z);
/* Calculate bottom face UVs. */
for (const int y : IndexRange(config.edges_y)) {
for (const int x : IndexRange(config.edges_x)) {
uvs[loop_index++] = float2(0.25f + x * x_delta, 0.375f - y * y_delta);
uvs[loop_index++] = float2(0.25f + x * x_delta, 0.375f - (y + 1) * y_delta);
uvs[loop_index++] = float2(0.25f + (x + 1) * x_delta, 0.375f - (y + 1) * y_delta);
uvs[loop_index++] = float2(0.25f + (x + 1) * x_delta, 0.375f - y * y_delta);
}
}
/* Calculate front face UVs. */
for (const int z : IndexRange(config.edges_z)) {
for (const int x : IndexRange(config.edges_x)) {
uvs[loop_index++] = float2(0.25f + x * x_delta, 0.375f + z * z_delta);
uvs[loop_index++] = float2(0.25f + (x + 1) * x_delta, 0.375f + z * z_delta);
uvs[loop_index++] = float2(0.25f + (x + 1) * x_delta, 0.375f + (z + 1) * z_delta);
uvs[loop_index++] = float2(0.25f + x * x_delta, 0.375f + (z + 1) * z_delta);
}
}
/* Calculate top face UVs. */
for (const int y : IndexRange(config.edges_y)) {
for (const int x : IndexRange(config.edges_x)) {
uvs[loop_index++] = float2(0.25f + x * x_delta, 0.625f + y * y_delta);
uvs[loop_index++] = float2(0.25f + (x + 1) * x_delta, 0.625f + y * y_delta);
uvs[loop_index++] = float2(0.25f + (x + 1) * x_delta, 0.625f + (y + 1) * y_delta);
uvs[loop_index++] = float2(0.25f + x * x_delta, 0.625f + (y + 1) * y_delta);
}
}
/* Calculate back face UVs. */
for (const int z : IndexRange(config.edges_z)) {
for (const int x : IndexRange(config.edges_x)) {
uvs[loop_index++] = float2(1.0f - x * x_delta, 0.375f + z * z_delta);
uvs[loop_index++] = float2(1.0f - x * x_delta, 0.375f + (z + 1) * z_delta);
uvs[loop_index++] = float2(1.0f - (x + 1) * x_delta, 0.375f + (z + 1) * z_delta);
uvs[loop_index++] = float2(1.0f - (x + 1) * x_delta, 0.375f + z * z_delta);
}
}
/* Calculate left face UVs. */
for (const int z : IndexRange(config.edges_z)) {
for (const int y : IndexRange(config.edges_y)) {
uvs[loop_index++] = float2(0.25f - y * y_delta, 0.375f + z * z_delta);
uvs[loop_index++] = float2(0.25f - y * y_delta, 0.375f + (z + 1) * z_delta);
uvs[loop_index++] = float2(0.25f - (y + 1) * y_delta, 0.375f + (z + 1) * z_delta);
uvs[loop_index++] = float2(0.25f - (y + 1) * y_delta, 0.375f + z * z_delta);
}
}
/* Calculate right face UVs. */
for (const int z : IndexRange(config.edges_z)) {
for (const int y : IndexRange(config.edges_y)) {
uvs[loop_index++] = float2(0.50f + y * y_delta, 0.375f + z * z_delta);
uvs[loop_index++] = float2(0.50f + (y + 1) * y_delta, 0.375f + z * z_delta);
uvs[loop_index++] = float2(0.50f + (y + 1) * y_delta, 0.375f + (z + 1) * z_delta);
uvs[loop_index++] = float2(0.50f + y * y_delta, 0.375f + (z + 1) * z_delta);
}
}
uv_attribute.finish();
}
Mesh *create_cuboid_mesh(const float3 &size,
const int verts_x,
const int verts_y,
const int verts_z,
const bke::AttributeIDRef &uv_id)
{
const CuboidConfig config(size, verts_x, verts_y, verts_z);
Mesh *mesh = BKE_mesh_new_nomain(config.vertex_count, 0, config.face_count, config.loop_count);
MutableSpan<float3> positions = mesh->vert_positions_for_write();
MutableSpan<int> corner_verts = mesh->corner_verts_for_write();
bke::mesh_smooth_set(*mesh, false);
calculate_positions(config, positions);
offset_indices::fill_constant_group_size(4, 0, mesh->face_offsets_for_write());
calculate_corner_verts(config, corner_verts);
bke::mesh_calc_edges(*mesh, false, false);
if (uv_id) {
calculate_uvs(config, mesh, uv_id);
}
const float3 bounds = size * 0.5f;
mesh->bounds_set_eager({-bounds, bounds});
mesh->tag_loose_verts_none();
mesh->tag_overlapping_none();
return mesh;
}
Mesh *create_cuboid_mesh(const float3 &size,
const int verts_x,
const int verts_y,
const int verts_z)
{
return create_cuboid_mesh(size, verts_x, verts_y, verts_z, {});
}
} // namespace blender::geometry