Start work on shader pipeline system

- Unbulit, untested so far
 - Will ultimately supersede shader contexts/templating
 - Laying framework for better compile errors via Span.java

src/main/java/com/jozufozu/flywheel/backend/loading/TaggedStruct.java

@@ -10,13 +10,13 @@ import java.util.regex.Pattern;
 public class TaggedStruct {
 
 	// https://regexr.com/5t207
-	static final Pattern taggedStruct = Pattern.compile("#\\[(\\w*)]\\s*struct\\s+([\\w\\d]*)\\s*\\{([\\w\\d \\t#\\[\\](),;\\n]*)}\\s*;");
+	public static final Pattern taggedStruct = Pattern.compile("#\\[(\\w*)]\\s*struct\\s+([\\w\\d]*)\\s*\\{([\\w\\d \\t#\\[\\](),;\\n]*)}\\s*;");
 
-	int srcStart, srcEnd;
-	String source;
-	String tag;
-	String name;
-	String body;
+	public int srcStart, srcEnd;
+	public String source;
+	public String tag;
+	public String name;
+	public String body;
 
 	List<TaggedField> fields = new ArrayList<>(4);
 	Map<String, String> fields2Types = new HashMap<>();

src/main/java/com/jozufozu/flywheel/backend/pipeline/ShaderFunction.java

@@ -0,0 +1,20 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import com.jozufozu.flywheel.backend.pipeline.span.Span;
+
+import java.util.regex.Pattern;
+
+public class ShaderFunction {
+
+	public static final Pattern assignment = Pattern.compile("(\\w+)\\s*=");
+
+	private final Span returnType;
+	private final Span name;
+	private final Span body;
+
+	public ShaderFunction(Span self, Span returnType, Span name, Span body) {
+		this.returnType = returnType;
+		this.name = name;
+		this.body = body;
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/ShaderStruct.java

@@ -0,0 +1,42 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import com.jozufozu.flywheel.backend.loading.Program;
+import com.jozufozu.flywheel.backend.loading.TaggedField;
+import com.jozufozu.flywheel.backend.loading.TypeHelper;
+import com.jozufozu.flywheel.backend.pipeline.span.Span;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class ShaderStruct {
+
+	// https://regexr.com/5t207
+	public static final Pattern struct = Pattern.compile("struct\\s+([\\w\\d]*)\\s*\\{([\\w\\d \\t#\\[\\](),;\\n]*)}\\s*;");
+
+	public Span name;
+	public Span body;
+
+	List<StructField> fields = new ArrayList<>(4);
+	Map<String, String> fields2Types = new HashMap<>();
+
+	public ShaderStruct(Span self, Span name, Span body) {
+		Matcher fielder = StructField.fieldPattern.matcher(body.getValue());
+
+		while (fielder.find()) {
+			fields.add(new StructField(fielder));
+			fields2Types.put(fielder.group(2), fielder.group(1));
+		}
+	}
+
+	public void addPrefixedAttributes(Program builder, String prefix) {
+		for (StructField field : fields) {
+			int attributeCount = TypeHelper.getAttributeCount(field.type);
+
+			builder.addAttribute(prefix + field.name, attributeCount);
+		}
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/SourceFile.java

@@ -0,0 +1,108 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import java.io.BufferedReader;
+import java.io.StringReader;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Stream;
+
+import com.jozufozu.flywheel.backend.ShaderSources;
+
+import com.jozufozu.flywheel.backend.pipeline.span.ErrorSpan;
+import com.jozufozu.flywheel.backend.pipeline.span.Span;
+
+import com.jozufozu.flywheel.backend.pipeline.span.StringSpan;
+
+import net.minecraft.util.ResourceLocation;
+
+public class SourceFile {
+	// #use "valid_namespace:valid/path_to_file.glsl"
+	private static final Pattern includePattern = Pattern.compile("#use \"(\\w+:[\\w./]+)\"");
+
+	// https://regexr.com/60n3d
+	public static final Pattern functionDeclaration = Pattern.compile("(\\w+)\\s+(\\w+)\\s*\\(([\\w,\\s]*)\\)\\s*\\{");
+
+	public static final Pattern versionDetector = Pattern.compile("#version[^\\n]*");
+
+	public final ResourceLocation name;
+	private final String source;
+	private final ShaderSources loader;
+
+	private final Map<String, ShaderFunction> functions = new HashMap<>();
+
+	public SourceFile(ShaderSources loader, ResourceLocation name, String source) {
+		this.loader = loader;
+		this.name = name;
+		this.source = source;
+
+		parseFunctions();
+	}
+
+	public String getSource() {
+		return source;
+	}
+
+	protected void parseFunctions() {
+		Matcher matcher = functionDeclaration.matcher(source);
+
+		while (matcher.find()) {
+			Span type = Span.fromMatcherGroup(this, matcher, 1);
+			Span name = Span.fromMatcherGroup(this, matcher, 2);
+
+			int blockStart = matcher.end();
+			int blockEnd = findEndOfBlock(blockStart);
+
+			Span self;
+			Span body;
+			if (blockEnd > blockStart) {
+				self = new StringSpan(this, matcher.start(), blockEnd);
+				body = new StringSpan(this, blockStart, blockEnd);
+			} else {
+				self = new ErrorSpan(this, matcher.start(), matcher.end());
+				body = new ErrorSpan(this, blockStart);
+			}
+
+			ShaderFunction function = new ShaderFunction(self, type, name, body);
+
+			functions.put(name.getValue(), function);
+		}
+	}
+
+	private int findEndOfBlock(int end) {
+		char[] rest = source.substring(end).toCharArray();
+
+		int blockDepth = 0;
+		for (int i = 0; i < rest.length; i++) {
+			char ch = rest[i];
+
+			if (ch == '{') blockDepth++;
+			if (ch == '}') blockDepth--;
+
+			if (blockDepth < 0) {
+				return end + i;
+			}
+		}
+
+		return -1;
+	}
+
+	public String printSource() {
+		StringBuilder builder = new StringBuilder();
+
+		builder.append("Source for shader '").append(name).append("':\n");
+		int i = 1;
+		for (String s : source.split("\n")) {
+			builder.append(String.format("%1$4s: ", i++))
+				   .append(s)
+				   .append('\n');
+		}
+
+		return builder.toString();
+	}
+
+	public static Stream<String> lines(String s) {
+		return new BufferedReader(new StringReader(s)).lines();
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/StructField.java

@@ -0,0 +1,35 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import com.jozufozu.flywheel.backend.loading.LayoutTag;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class StructField {
+	public static final Pattern fieldPattern = Pattern.compile("(\\S+)\\s*(\\S+);");
+
+	public String name;
+	public String type;
+	public LayoutTag layout;
+
+	public StructField(Matcher fieldMatcher) {
+		type = fieldMatcher.group(2);
+		name = fieldMatcher.group(3);
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public String getType() {
+		return type;
+	}
+
+	@Override
+	public String toString() {
+		return "TaggedField{" +
+				"name='" + name + '\'' +
+				", type='" + type + '\'' +
+				'}';
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/WorldShaderPipeline.java

@@ -0,0 +1,16 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import com.jozufozu.flywheel.core.shader.IMultiProgram;
+import com.jozufozu.flywheel.core.shader.StateSensitiveMultiProgram;
+import com.jozufozu.flywheel.core.shader.WorldProgram;
+
+import javax.annotation.Nullable;
+
+public class WorldShaderPipeline<P extends WorldProgram> {
+
+	@Nullable // TODO: temporary null return
+	public IMultiProgram<P> compile(SourceFile file) {
+
+		return null;
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/package-info.java

@@ -0,0 +1,7 @@
+@ParametersAreNonnullByDefault
+@MethodsReturnNonnullByDefault
+package com.jozufozu.flywheel.backend.pipeline;
+
+import mcp.MethodsReturnNonnullByDefault;
+
+import javax.annotation.ParametersAreNonnullByDefault;

src/main/java/com/jozufozu/flywheel/backend/pipeline/span/ErrorSpan.java

@@ -0,0 +1,18 @@
+package com.jozufozu.flywheel.backend.pipeline.span;
+
+import com.jozufozu.flywheel.backend.pipeline.SourceFile;
+
+public class ErrorSpan extends Span {
+	public ErrorSpan(SourceFile in, int loc) {
+		super(in, loc, loc);
+	}
+
+	public ErrorSpan(SourceFile in, int start, int end) {
+		super(in, start, end);
+	}
+
+	@Override
+	public String getValue() {
+		return "";
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/span/Span.java

@@ -0,0 +1,40 @@
+package com.jozufozu.flywheel.backend.pipeline.span;
+
+import com.jozufozu.flywheel.backend.pipeline.SourceFile;
+
+import java.util.regex.Matcher;
+
+public abstract class Span {
+
+	protected final SourceFile in;
+	protected final int start;
+	protected final int end;
+
+	public Span(SourceFile in, int start, int end) {
+		this.in = in;
+		this.start = start;
+		this.end = end;
+	}
+
+	public SourceFile getSourceFile() {
+		return in;
+	}
+
+	public int getStart() {
+		return start;
+	}
+
+	public int getEnd() {
+		return end;
+	}
+
+	public abstract String getValue();
+
+	public static Span fromMatcherGroup(SourceFile src, Matcher m, int group) {
+		return new StringSpan(src, m.start(group), m.end(group));
+	}
+
+	public static Span fromMatcher(SourceFile src, Matcher m) {
+		return new StringSpan(src, m.start(), m.end());
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/span/StringSpan.java

@@ -0,0 +1,15 @@
+package com.jozufozu.flywheel.backend.pipeline.span;
+
+import com.jozufozu.flywheel.backend.pipeline.SourceFile;
+
+public class StringSpan extends Span {
+
+	public StringSpan(SourceFile in, int start, int end) {
+		super(in, start, end);
+	}
+
+	@Override
+	public String getValue() {
+		return in.getSource().substring(start, end);
+	}
+}