Fry3DX 0.4: an easy 3D modeller

Shapes with live settings, shape editing, knife and hole tools, drawing
shapes onto other objects, combining objects (add / subtract / overlap),
copies, thickness, painting with stickers and layers, a Layout tab, a
Print tab with checks, packed .fry files with autosave, export to GLB,
glTF, FBX, OBJ, 3MF, STL and PLY, folders in Layers, its own crash
screen, and a website for GitHub Pages in docs/.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NMSrd5oe1GpUD7E6d825KP

engine/shaders/box.vert

@@ -0,0 +1,26 @@
+#version 460
+// Axis-aligned boxes generated from the vertex index: 36 vertices, no vertex buffer.
+#include "backend.glsl"
+PUSH_BLOCK {
+    mat4 viewProj;
+    vec4 center;  // xyz, w = texture index
+    vec4 extents; // xyz = half size
+    vec4 color;
+} pc;
+
+layout(location = 0) out vec3 v_normal;
+layout(location = 1) out vec3 v_world;
+
+const vec3 kNormals[6] = vec3[](vec3(1,0,0), vec3(-1,0,0), vec3(0,1,0), vec3(0,-1,0), vec3(0,0,1), vec3(0,0,-1));
+const vec2 kQuad[6] = vec2[](vec2(-1,-1), vec2(1,-1), vec2(1,1), vec2(-1,-1), vec2(1,1), vec2(-1,1));
+
+void main() {
+    int face = VERTEX_ID / 6;
+    vec3 n = kNormals[face];
+    vec3 t = abs(n.z) > 0.5 ? vec3(1,0,0) : vec3(0,0,1);
+    vec3 b = cross(n, t);
+    vec2 q = kQuad[VERTEX_ID % 6];
+    v_world = pc.center.xyz + (n + t * q.x + b * q.y) * pc.extents.xyz;
+    v_normal = n;
+    gl_Position = pc.viewProj * vec4(v_world, 1.0);
+}