Port Age lighting and animated sky styles to 26.3 beta

ports/mc263/build.gradle

@@ -121,6 +121,71 @@ def generatePortLanguage = tasks.register('generatePortLanguage', GeneratePortLa
 }
 sourceSets.main.resources.srcDir generatePortLanguage
 
+// Derive registered presentation variants without duplicating vanilla gameplay settings.
+abstract class GeneratePortDimensionTypes extends DefaultTask {
+    @InputFile abstract RegularFileProperty getMinecraftJar()
+    @OutputDirectory abstract DirectoryProperty getOutputDir()
+
+    @TaskAction void generate() {
+        new java.util.zip.ZipFile(minecraftJar.get().asFile).withCloseable { archive ->
+            def entry = archive.getEntry('data/minecraft/dimension_type/overworld.json')
+            if (entry == null) throw new GradleException('Missing vanilla Overworld dimension type')
+            String template = archive.getInputStream(entry).withCloseable { it.getText('UTF-8') }
+            def dayEntry = archive.getEntry('data/minecraft/timeline/day.json')
+            if (dayEntry == null) throw new GradleException('Missing vanilla day timeline')
+            def day = archive.getInputStream(dayEntry).withCloseable {
+                new groovy.json.JsonSlurper().parseText(it.getText('UTF-8'))
+            }
+            // Keep gameplay schedules and illumination, but do not tint these
+            // native non-Overworld sky backgrounds blue/black with the day cycle.
+            ['fog_color', 'sky_color', 'cloud_color'].each { day.tracks.remove("minecraft:visual/${it}".toString()) }
+            // Markers are global per clock and already owned by minecraft:day.
+            day.remove('time_markers')
+            File dayFile = new File(outputDir.get().asFile, 'data/rivencraft/timeline/age_sky_day.json')
+            dayFile.parentFile.mkdirs()
+            dayFile.text = groovy.json.JsonOutput.prettyPrint(groovy.json.JsonOutput.toJson(day)) + '\n'
+            File timelineTag = new File(outputDir.get().asFile, 'data/rivencraft/tags/timeline/age_sky.json')
+            timelineTag.parentFile.mkdirs()
+            timelineTag.text = groovy.json.JsonOutput.prettyPrint(groovy.json.JsonOutput.toJson([
+                    values: ['#minecraft:universal', 'rivencraft:age_sky_day',
+                             'minecraft:moon', 'minecraft:early_game']])) + '\n'
+            ['overworld', 'nether', 'end', 'static'].each { sky ->
+                ['age_normal', 'age_dark', 'age_bright', 'age_cave_bright'].each { lighting ->
+                    if (sky == 'overworld' && lighting == 'age_normal') return
+                    String name = lighting + (sky == 'overworld' ? '' : "_sky_${sky}")
+                    def definition = new groovy.json.JsonSlurper().parseText(template)
+                    definition.has_skylight = lighting in ['age_normal', 'age_bright']
+                    definition.ambient_light = lighting in ['age_bright', 'age_cave_bright'] ? 1.0 : 0.0
+                    // 26.3's lightmap reads this attribute, not ambient_light.
+                    if (definition.ambient_light == 1.0)
+                        definition.attributes['minecraft:visual/ambient_light_color'] = '#ffffff'
+                    if (sky != 'overworld') {
+                        definition.skybox = sky == 'end' ? 'end' : 'none'
+                        definition.attributes['minecraft:visual/fog_color'] = sky == 'static' ? '#929292' : sky == 'end' ? '#181318' : '#6b2725'
+                        definition.attributes['minecraft:visual/sky_color'] = sky == 'static' ? '#929292' : sky == 'end' ? '#000000' : '#6b2725'
+                        definition.attributes['minecraft:visual/cloud_color'] = '#00000000'
+                        if (sky == 'nether') {
+                            definition.attributes['minecraft:visual/fog_start_distance'] = 10.0
+                            definition.attributes['minecraft:visual/fog_end_distance'] = 96.0
+                        }
+                        definition.timelines = '#rivencraft:age_sky'
+                    }
+                    File result = new File(outputDir.get().asFile, "data/rivencraft/dimension_type/${name}.json")
+                    result.parentFile.mkdirs()
+                    result.text = groovy.json.JsonOutput.prettyPrint(groovy.json.JsonOutput.toJson(definition)) + '\n'
+                }
+            }
+        }
+    }
+}
+
+def generatePortDimensionTypes = tasks.register('generatePortDimensionTypes', GeneratePortDimensionTypes) {
+    dependsOn 'createMinecraftArtifacts'
+    minecraftJar.set(layout.buildDirectory.file("moddev/artifacts/minecraft-patched-${neo_version}.jar"))
+    outputDir.set(layout.buildDirectory.dir('generated/resources/dimensionTypes'))
+}
+sourceSets.main.resources.srcDir generatePortDimensionTypes
+
 tasks.named('processResources', ProcessResources).configure {
     // Reuse the existing sprite and base model without copying binary assets.
     from('../../src/main/resources') {