feat(editor): add --gen-mesh-archway semicircular arched doorway

Two cylindrical pillars hold up a curved keystone vault: the
vault is a series of N angular wedge segments tracing a half-
circle from pillar-top to pillar-top. Each wedge has inner +
outer radial faces and front/back side caps.

Defaults: 3w × 3h pillars, thickness=0.4, 12 arch segments.
The fancier sibling of --gen-mesh-portal (flat lintel) — the
archway gives a temple/cathedral aesthetic. Brings the
procedural mesh primitive set to 25.
This commit is contained in:
Kelsi 2026-05-08 15:49:05 -07:00
parent 91b667991a
commit 9365792c57

View file

@ -601,6 +601,8 @@ static void printUsage(const char* argv0) {
std::printf(" Round altar: stacked stepped discs descending from a flat top (default 3 steps)\n");
std::printf(" --gen-mesh-portal <wom-base> [width] [height] [postThickness] [lintelHeight]\n");
std::printf(" Doorway frame: two side posts + top lintel (default 2.5w × 4h)\n");
std::printf(" --gen-mesh-archway <wom-base> [width] [pillarHeight] [thickness] [archSegs]\n");
std::printf(" Semicircular arched doorway: two pillars + curved keystone vault (default 12 segs)\n");
std::printf(" Procedural tree: cylindrical trunk + spherical foliage (default 0.1/2.0/0.7)\n");
std::printf(" --displace-mesh <wom-base> <heightmap.png> [scale]\n");
std::printf(" Offset each vertex along its normal by heightmap brightness × scale (default 1.0)\n");
@ -1136,6 +1138,7 @@ int main(int argc, char* argv[]) {
"--gen-mesh-rock", "--gen-mesh-pillar", "--gen-mesh-bridge",
"--gen-mesh-tower", "--gen-mesh-house", "--gen-mesh-fountain",
"--gen-mesh-statue", "--gen-mesh-altar", "--gen-mesh-portal",
"--gen-mesh-archway",
"--gen-texture-gradient",
"--gen-mesh-from-heightmap", "--export-mesh-heightmap",
"--displace-mesh",
@ -24133,6 +24136,187 @@ int main(int argc, char* argv[]) {
std::printf(" vertices : %zu\n", wom.vertices.size());
std::printf(" triangles : %zu\n", wom.indices.size() / 3);
return 0;
} else if (std::strcmp(argv[i], "--gen-mesh-archway") == 0 && i + 1 < argc) {
// Semicircular arched doorway. Two cylindrical pillars
// hold up a curved keystone vault: the vault is a series
// of N angular wedge segments tracing a half-circle from
// pillar-top to pillar-top. The opening is the empty
// semicircular space below.
//
// The 25th procedural mesh primitive — the "fancier"
// sibling of --gen-mesh-portal which uses a flat lintel.
std::string womBase = argv[++i];
float width = 3.0f; // outer-to-outer pillar centers along Z
float pillarH = 3.0f; // pillar height (Y)
float thickness = 0.4f; // pillar radius and arch radial thickness
int archSegs = 12; // segments around the half-circle
if (i + 1 < argc && argv[i + 1][0] != '-') {
try { width = std::stof(argv[++i]); } catch (...) {}
}
if (i + 1 < argc && argv[i + 1][0] != '-') {
try { pillarH = std::stof(argv[++i]); } catch (...) {}
}
if (i + 1 < argc && argv[i + 1][0] != '-') {
try { thickness = std::stof(argv[++i]); } catch (...) {}
}
if (i + 1 < argc && argv[i + 1][0] != '-') {
try { archSegs = std::stoi(argv[++i]); } catch (...) {}
}
if (width <= 0 || pillarH <= 0 || thickness <= 0 ||
archSegs < 4 || archSegs > 64 ||
thickness * 4 >= width) {
std::fprintf(stderr,
"gen-mesh-archway: thickness×4 < width, archSegs 4..64\n");
return 1;
}
if (womBase.size() >= 4 &&
womBase.substr(womBase.size() - 4) == ".wom") {
womBase = womBase.substr(0, womBase.size() - 4);
}
wowee::pipeline::WoweeModel wom;
wom.name = std::filesystem::path(womBase).stem().string();
wom.version = 3;
const float pi = 3.14159265358979f;
const int pillarSegs = 16;
auto addV = [&](glm::vec3 p, glm::vec3 n, glm::vec2 uv) -> uint32_t {
wowee::pipeline::WoweeModel::Vertex vtx;
vtx.position = p; vtx.normal = n; vtx.texCoord = uv;
wom.vertices.push_back(vtx);
return static_cast<uint32_t>(wom.vertices.size() - 1);
};
// Cylindrical pillar at given (cx, cz), from y=0 to y=pillarH.
auto pillar = [&](float cx, float cz) {
float r = thickness;
uint32_t bot = static_cast<uint32_t>(wom.vertices.size());
for (int sg = 0; sg <= pillarSegs; ++sg) {
float u = static_cast<float>(sg) / pillarSegs;
float ang = u * 2.0f * pi;
glm::vec3 p(cx + r * std::cos(ang), 0,
cz + r * std::sin(ang));
glm::vec3 n(std::cos(ang), 0, std::sin(ang));
addV(p, n, {u, 0});
}
uint32_t top = static_cast<uint32_t>(wom.vertices.size());
for (int sg = 0; sg <= pillarSegs; ++sg) {
float u = static_cast<float>(sg) / pillarSegs;
float ang = u * 2.0f * pi;
glm::vec3 p(cx + r * std::cos(ang), pillarH,
cz + r * std::sin(ang));
glm::vec3 n(std::cos(ang), 0, std::sin(ang));
addV(p, n, {u, 1});
}
for (int sg = 0; sg < pillarSegs; ++sg) {
wom.indices.insert(wom.indices.end(), {
bot + sg, top + sg, bot + sg + 1,
bot + sg + 1, top + sg, top + sg + 1
});
}
// Caps
uint32_t bc = addV({cx, 0, cz}, {0, -1, 0}, {0.5f, 0.5f});
uint32_t tc = addV({cx, pillarH, cz}, {0, 1, 0}, {0.5f, 0.5f});
for (int sg = 0; sg < pillarSegs; ++sg) {
wom.indices.insert(wom.indices.end(),
{bc, bot + sg + 1, bot + sg});
wom.indices.insert(wom.indices.end(),
{tc, top + sg, top + sg + 1});
}
};
float pillarZ = (width - 2 * thickness) * 0.5f;
pillar(0, pillarZ);
pillar(0, -pillarZ);
// Arch vault: trace half-circle from (z = +pillarZ, y = pillarH)
// up over to (z = -pillarZ, y = pillarH). Center of arch:
// (z = 0, y = pillarH). Arch radius = pillarZ.
// Inner arch (radius pillarZ - thickness*0.5) and outer
// (radius pillarZ + thickness*0.5) — the vault sits between.
float archCY = pillarH;
float arcInner = pillarZ - thickness * 0.5f;
float arcOuter = pillarZ + thickness * 0.5f;
// Each segment: 4 verts (inner-near, outer-near, inner-far,
// outer-far) extruded along X by thickness so the vault
// has front and back faces.
float archX = thickness * 0.5f; // half-depth in X
// Build vertex rings for inner and outer surfaces at
// each segment boundary, then connect.
// Top half-circle goes from theta=0 to theta=pi.
std::vector<glm::vec3> innerRing;
std::vector<glm::vec3> outerRing;
for (int s = 0; s <= archSegs; ++s) {
float t = static_cast<float>(s) / archSegs;
float theta = t * pi; // 0..pi
float zi = arcInner * std::cos(theta);
float yi = arcInner * std::sin(theta);
float zo = arcOuter * std::cos(theta);
float yo = arcOuter * std::sin(theta);
innerRing.push_back({0, archCY + yi, zi});
outerRing.push_back({0, archCY + yo, zo});
}
// For each segment, add 8 vertices (4 corners × front/back face)
// and stitch them into 6 quads = 12 tris each.
for (int s = 0; s < archSegs; ++s) {
glm::vec3 i0 = innerRing[s];
glm::vec3 i1 = innerRing[s + 1];
glm::vec3 o0 = outerRing[s];
glm::vec3 o1 = outerRing[s + 1];
// Estimate outward (radial) normal as midpoint of o0+o1
// direction from center.
glm::vec3 outDir = glm::normalize(glm::vec3(0,
(i0.y + i1.y + o0.y + o1.y) * 0.25f - archCY,
(i0.z + i1.z + o0.z + o1.z) * 0.25f));
glm::vec3 frontN(1, 0, 0);
glm::vec3 backN(-1, 0, 0);
auto V = [&](glm::vec3 p, glm::vec3 n) {
return addV(p, n, {0, 0});
};
// Outer surface (top of arch): faces outward radially
uint32_t a = V({-archX, o0.y, o0.z}, outDir);
uint32_t b = V({ archX, o0.y, o0.z}, outDir);
uint32_t c = V({ archX, o1.y, o1.z}, outDir);
uint32_t d = V({-archX, o1.y, o1.z}, outDir);
wom.indices.insert(wom.indices.end(), {a, b, c, a, c, d});
// Inner surface (underside of arch): faces inward
uint32_t e = V({-archX, i0.y, i0.z}, -outDir);
uint32_t f = V({ archX, i0.y, i0.z}, -outDir);
uint32_t g = V({ archX, i1.y, i1.z}, -outDir);
uint32_t h = V({-archX, i1.y, i1.z}, -outDir);
wom.indices.insert(wom.indices.end(), {e, g, f, e, h, g});
// Front face (+X) of this wedge
uint32_t fi0 = V({ archX, i0.y, i0.z}, frontN);
uint32_t fo0 = V({ archX, o0.y, o0.z}, frontN);
uint32_t fo1 = V({ archX, o1.y, o1.z}, frontN);
uint32_t fi1 = V({ archX, i1.y, i1.z}, frontN);
wom.indices.insert(wom.indices.end(),
{fi0, fo0, fo1, fi0, fo1, fi1});
// Back face (-X)
uint32_t bi0 = V({-archX, i0.y, i0.z}, backN);
uint32_t bo0 = V({-archX, o0.y, o0.z}, backN);
uint32_t bo1 = V({-archX, o1.y, o1.z}, backN);
uint32_t bi1 = V({-archX, i1.y, i1.z}, backN);
wom.indices.insert(wom.indices.end(),
{bi0, bo1, bo0, bi0, bi1, bo1});
}
wowee::pipeline::WoweeModel::Batch batch;
batch.indexStart = 0;
batch.indexCount = static_cast<uint32_t>(wom.indices.size());
batch.textureIndex = 0;
wom.batches.push_back(batch);
float maxY = pillarH + arcOuter;
wom.boundMin = glm::vec3(-thickness, 0, -width * 0.5f);
wom.boundMax = glm::vec3( thickness, maxY, width * 0.5f);
if (!wowee::pipeline::WoweeModelLoader::save(wom, womBase)) {
std::fprintf(stderr,
"gen-mesh-archway: failed to save %s.wom\n", womBase.c_str());
return 1;
}
std::printf("Wrote %s.wom\n", womBase.c_str());
std::printf(" width : %.3f\n", width);
std::printf(" pillar H : %.3f\n", pillarH);
std::printf(" thickness : %.3f\n", thickness);
std::printf(" arch segs : %d (radius %.3f)\n", archSegs, arcOuter);
std::printf(" apex Y : %.3f\n", maxY);
std::printf(" vertices : %zu\n", wom.vertices.size());
std::printf(" triangles : %zu\n", wom.indices.size() / 3);
return 0;
} else if (std::strcmp(argv[i], "--displace-mesh") == 0 && i + 2 < argc) {
// Displaces each vertex along its current normal by the
// heightmap brightness × scale. UVs determine where each