Generalize case combinations, relativize rotations

README.md

@@ -497,17 +497,25 @@ Declarations might look like this:
 ```yaml
 cases:
     case_name:
-        - outline: <outline ref>
+        - type: outline
+          name: <outline ref>
           extrude: num # default = 1
           shift: [x, y, z] # default = [0, 0, 0]
           rotate: [ax, ay, az] # default = [0, 0, 0]
           operation: add | subtract | intersect # default = add
+        - type: case
+          name: <case_ref>
+          # extrude makes no sense here...
+          shift: # same as above
+          rotate: # same as above
+          operation: # same as above
         - ...
     ...
 ```
 
-`outline` specifies which outline to import onto the xy plane, while `extrude` specifies how much it should be extruded along the z axis.
-After that, the object is `shift`d, `rotate`d, and combined with what we have so far according to `operation`.
+When the `type` is `outline`, `name` specifies which outline to import onto the xy plane, while `extrude` specifies how much it should be extruded along the z axis.
+When the `type` is `case`, `name` specifies which case to use.
+After having established our base 3D object, it is (relatively!) `rotate`d, `shift`ed, and combined with what we have so far according to `operation`.
 If we only want to use an object as a building block for further objects, we can employ the same "start with an underscore" trick we learned at the outlines section to make it "private".
 
 
@@ -543,6 +551,7 @@ If we only want to use an object as a building block for further objects, we can
 
 
 
+
 
 
 ## A concrete case example

src/cases.js

@@ -4,68 +4,120 @@ const a = require('./assert')
 
 exports.parse = (config, outlines) => {
 
-    const cases = a.sane(config, 'cases', 'object')
+    const cases_config = a.sane(config, 'cases', 'object')
+
+    const scripts = {}
+    const cases = {}
     const results = {}
 
-    for (const [case_name, case_config] of Object.entries(cases)) {
+    const resolve = (case_name, resolved_scripts=new Set(), resolved_cases=new Set()) => {
+        for (const o of Object.values(cases[case_name].outline_dependencies)) {
+            resolved_scripts.add(o)
+        }
+        for (const c of Object.values(cases[case_name].case_dependencies)) {
+            resolved_cases.add(c)
+            resolve(c, resolved_scripts, resolved_cases)
+        }
+        result = []
+        for (const o of resolved_scripts) {
+            result.push(scripts[o] + '\n\n')
+        }
+        for (const c of resolved_cases) {
+            result.push(cases[c].body)
+        }
+        result.push(cases[case_name].body)
+        result.push(`
+        
+            function main() {
+                return ${case_name}_case_fn();
+            }
+
+        `)
+        return result.join('')
+    }
+
+    for (const [case_name, case_config] of Object.entries(cases_config)) {
 
         // config sanitization
         const parts = a.sane(case_config, `cases.${case_name}`, 'array')
 
-        const scripts = []
-        const main = []
-
+        const body = []
+        const case_dependencies = []
+        const outline_dependencies = []
         let part_index = 0
         for (const part of parts) {
             const part_name = `cases.${case_name}[${++part_index}]`
-            a.detect_unexpected(part, part_name, ['outline', 'extrude', 'shift', 'rotate', 'operation'])
-            const outline = outlines[part.outline]
-            a.assert(outline, `Field ${part_name}.outline does not name a valid outline!`)
-            const extrude = a.sane(part.extrude || 1, `${part_name}.extrude`, 'number')
+            const part_var = `${case_name}__part_${part_index}`
+            a.detect_unexpected(part, part_name, ['type', 'name', 'extrude', 'shift', 'rotate', 'operation'])
+            const type = a.in(part.type, `${part_name}.type`, ['outline', 'case'])
+            const name = a.sane(part.name, `${part_name}.name`, 'string')
             const shift = a.numarr(part.shift || [0, 0, 0], `${part_name}.shift`, 3)
             const rotate = a.numarr(part.rotate || [0, 0, 0], `${part_name}.rotate`, 3)
             const operation = a.in(part.operation || 'add', `${part_name}.operation`, ['add', 'subtract', 'intersect'])
 
+            let base
+            if (type == 'outline') {
+                const extrude = a.sane(part.extrude || 1, `${part_name}.extrude`, 'number')
+                const outline = outlines[name]
+                a.assert(outline, `Field "${part_name}.name" does not name a valid outline!`)
+                if (!scripts[name]) {
+                    scripts[name] = m.exporter.toJscadScript(outline, {
+                        functionName: `${name}_outline_fn`,
+                        extrude: extrude,
+                        indent: 4
+                    })
+                }
+                outline_dependencies.push(name)
+                base = `${name}_outline_fn()`
+            } else {
+                a.assert(part.extrude === undefined, `Field "${part_name}.extrude" should not be used when type=case!`)
+                a.in(name, `${part_name}.name`, Object.keys(cases))
+                case_dependencies.push(name)
+                base = `${name}_case_fn()`
+            }
+
             let op = 'union'
             if (operation == 'subtract') op = 'subtract'
             else if (operation == 'intersect') op = 'intersect'
 
-            const part_fn = `${part.outline}_fn`
-            const part_var = `${part.outline}_var`
-
-            scripts.push(m.exporter.toJscadScript(outline, {
-                functionName: part_fn,
-                extrude: extrude
-            }))
-
-            let op_statement = `let ${case_name} = ${part_var};`
+            let op_statement = `let result = ${part_var};`
             if (part_index > 1) {
-                op_statement = `${case_name} = ${case_name}.${op}(${part_var});`
+                op_statement = `result = result.${op}(${part_var});`
             }
 
-            main.push(`
+            body.push(`
 
                 // creating part ${part_index} of case ${case_name}
-                let ${part_var} = ${part_fn}();
+                let ${part_var} = ${base};
+
+                // make sure that rotations are relative
+                let ${part_var}_bounds = ${part_var}.getBounds();
+                let ${part_var}_x = ${part_var}_bounds[0].x + (${part_var}_bounds[1].x - ${part_var}_bounds[0].x) / 2
+                let ${part_var}_y = ${part_var}_bounds[0].y + (${part_var}_bounds[1].y - ${part_var}_bounds[0].y) / 2
+                ${part_var} = translate([-${part_var}_x, -${part_var}_y, 0], ${part_var});
                 ${part_var} = rotate(${JSON.stringify(rotate)}, ${part_var});
+                ${part_var} = translate([${part_var}_x, ${part_var}_y, 0], ${part_var});
+
                 ${part_var} = translate(${JSON.stringify(shift)}, ${part_var});
                 ${op_statement}
                 
             `)
         }
 
-        results[case_name] = `
+        cases[case_name] = {
+            body: `
 
-            // individual makerjs exports
-            ${scripts.join('\n\n')}
+                function ${case_name}_case_fn() {
+                    ${body.join('')}
+                    return result;
+                }
+            
+            `,
+            case_dependencies,
+            outline_dependencies
+        }
 
-            // combination of parts
-            function main() {
-                ${main.join('')}
-                return ${case_name};
-            }
-
-        `
+        results[case_name] = resolve(case_name)
     }
 
     return results