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/backend_gl.glsl

@@ -0,0 +1,26 @@
+// OpenGL 4.6 + ARB_bindless_texture (enabled by the loader's preamble): every texture is a
+// 64-bit handle (sampler state included) in a table, indexed like Vulkan's descriptor array.
+// Depth textures also get a comparison handle in a second table, for shadows.
+layout(std430, binding = 9) readonly buffer TextureHandles { uvec2 handles[]; } u_textureHandles;
+layout(std430, binding = 10) readonly buffer ShadowHandles { uvec2 handles[]; } u_shadowHandles;
+
+#define PUSH_BLOCK layout(std140, binding = 0) uniform Push
+#define VERTEX_ID gl_VertexID
+
+vec4 sampleTex(uint index, vec2 uv) {
+    return texture(sampler2D(u_textureHandles.handles[index]), uv);
+}
+
+ivec2 texSize(uint index) { return textureSize(sampler2D(u_textureHandles.handles[index]), 0); }
+
+vec4 fetchTex(uint index, ivec2 p) {
+    return texelFetch(sampler2D(u_textureHandles.handles[index]), p, 0);
+}
+
+vec4 sampleTexLod(uint index, vec2 uv, float lod) {
+    return textureLod(sampler2D(u_textureHandles.handles[index]), uv, lod);
+}
+
+float shadowTap(uint index, vec2 uv, vec2 lo, vec2 hi, float ref) {
+    return textureLod(sampler2DShadow(u_shadowHandles.handles[index]), vec3(clamp(uv, lo, hi), ref), 0.0);
+}