Add YAML reader

src/SConscript

@@ -21,6 +21,7 @@ files = [
     'object.cc',
     'object_sphere.cc',
     'object_plane.cc',
+    'reader_yaml.cc',
     'scene.cc',
     'writer_png.cc',
 ]
@@ -30,7 +31,7 @@ for f in files:
     objs.append(env.Object(f))
 
 lib = env.Library('charles', files)
-prog = env.Program('charles', ['charles.cc'], LIBS=[lib, 'png'])
+prog = env.Program('charles', ['charles.cc'], LIBS=[lib, 'png', 'yaml'])
 env.Alias('charles', prog)
 
 env.Default('charles')

src/reader.hh

@@ -0,0 +1,32 @@
+/* reader.hh
+ * vim: set tw=80:
+ * Eryn Wells <eryn@erynwells.me>
+ */
+/**
+ * Interface for an input file reader.
+ */
+
+
+#ifndef __READER_HH__
+#define __READER_HH__
+
+#include "scene.h"
+
+
+struct Reader
+{
+    Reader(Scene& scene)
+        : mScene(scene)
+    { }
+
+    virtual
+    ~Reader()
+    { }
+
+    virtual ssize_t read_file(const std::string& filename) = 0;
+
+protected:
+    Scene& mScene;
+};
+
+#endif /* __READER_HH__ */

src/reader_yaml.cc

@@ -0,0 +1,208 @@
+/* reader_yaml.cc
+ * vim: set tw=80:
+ * Eryn Wells <eryn@erynwells.me>
+ */
+/**
+ * An input file reader for YAML files.
+ */
+
+#include <cstdio>
+#include <stack>
+
+#include "yaml.h"
+
+#include "reader_yaml.hh"
+
+
+struct Parser;
+typedef std::stack<Parser *> ParserStack;
+
+
+struct Parser
+{
+    Parser(Scene& scene,
+           ParserStack& parsers)
+        : mScene(scene),
+          mParsers(parsers)
+    { }
+
+    virtual
+    ~Parser()
+    { }
+
+    virtual void
+    handle_start_event(yaml_event_t& event)
+    { }
+
+    virtual void
+    handle_end_event(yaml_event_t& event)
+    { }
+
+    virtual void
+    handle_event(yaml_event_t& event)
+    { }
+
+protected:
+    Scene& mScene;
+    ParserStack &mParsers;
+
+private:
+    Parser();
+    Parser(Parser& other);
+};
+
+
+struct DocumentParser
+    : public Parser
+{
+    DocumentParser(Scene& scene,
+                   ParserStack& parsers)
+        : Parser(scene, parsers)
+    {
+        printf("DocumentParser\n"); 
+    }
+
+    ~DocumentParser()
+    {
+        printf("~DocumentParser\n");
+    }
+
+    void
+    handle_event(yaml_event_t& event)
+    {
+        
+    }
+};
+
+
+struct StreamParser
+    : public Parser
+{
+    StreamParser(Scene& scene,
+                 ParserStack& parsers)
+        : Parser(scene, parsers)
+    {
+        printf("StreamParser\n"); 
+    }
+
+    ~StreamParser()
+    {
+        printf("~StreamParser\n"); 
+    }
+
+    void
+    handle_start_event(yaml_event_t& event)
+    {
+        printf("Stream start\n"); 
+    }
+
+    void
+    handle_end_event(yaml_event_t& event)
+    {
+        switch (event.type) {
+            case YAML_DOCUMENT_START_EVENT:
+                mParsers.push(new DocumentParser(mScene, mParsers));
+                mParsers.top()->handle_start_event(event);
+                break;
+            default:
+                /* TODO: Error out, somehow. */
+                break;
+        }
+    }
+
+    void
+    handle_event(yaml_event_t& event)
+    { }
+
+private:
+    StreamParser();
+    StreamParser(StreamParser& other);
+};
+
+
+struct SceneDocumentParser
+{
+
+};
+
+
+ssize_t
+YAMLReader::read_file(const std::string& filename)
+{
+
+    FILE *yaml_infile = fopen(filename.c_str(), "rb");
+    if (!yaml_infile) {
+        fprintf(stderr, "Couldn't open file: %s\n", filename.c_str());
+        return -1;
+    }
+
+    yaml_parser_t parser;
+    yaml_parser_initialize(&parser);
+
+    printf("Reading file: %s\n", filename.c_str());
+    yaml_parser_set_input_file(&parser, yaml_infile);
+
+    ParserStack parsers;
+    bool success = true;
+    bool done = false;
+    yaml_event_t event;
+    while (!done) {
+        if (!yaml_parser_parse(&parser, &event)) {
+            success = false;
+            goto error;
+        }
+
+        switch (event.type) {
+            case YAML_NO_EVENT:
+                printf("YAML_NO_EVENT\n");
+                break;
+
+            case YAML_STREAM_START_EVENT:
+                printf("YAML_STREAM_START_EVENT\n");
+                parsers.push(new StreamParser(mScene, parsers));
+                parsers.top()->handle_start_event(event);
+                break;
+            case YAML_STREAM_END_EVENT:
+                printf("YAML_STREAM_END_EVENT\n");
+                parsers.top()->handle_end_event(event);
+                delete parsers.top();
+                parsers.pop();
+                break;
+
+            case YAML_DOCUMENT_START_EVENT:
+                printf("YAML_DOCUMENT_START_EVENT\n");
+                break;
+            case YAML_DOCUMENT_END_EVENT:
+                printf("YAML_DOCUMENT_END_EVENT\n");
+                break;
+
+            case YAML_ALIAS_EVENT:
+                printf("YAML_ALIAS_EVENT\n");
+                break;
+            case YAML_SCALAR_EVENT:
+                printf("YAML_SCALAR_EVENT\n");
+                break;
+
+            case YAML_SEQUENCE_START_EVENT:
+                printf("YAML_SEQUENCE_START_EVENT\n");
+                break;
+            case YAML_SEQUENCE_END_EVENT:
+                printf("YAML_SEQUENCE_END_EVENT\n");
+                break;
+
+            case YAML_MAPPING_START_EVENT:
+                printf("YAML_MAPPING_START_EVENT\n");
+                break;
+            case YAML_MAPPING_END_EVENT:
+                printf("YAML_MAPPING_END_EVENT\n");
+                break;
+        }
+
+        done = (event.type == YAML_STREAM_END_EVENT);
+        yaml_event_delete(&event);
+    }
+
+error:
+    yaml_parser_delete(&parser);
+    return success;
+}

src/reader_yaml.hh

@@ -0,0 +1,29 @@
+/* reader_yaml.hh
+ * vim: set tw=80:
+ * Eryn Wells <eryn@erynwells.me>
+ */
+/**
+ * An input file reader for YAML files.
+ */
+
+
+#ifndef __READER_YAML_HH__
+#define __READER_YAML_HH__
+
+#include "reader.hh"
+#include "scene.h"
+
+
+struct YAMLReader
+    : public Reader
+{
+    YAMLReader(Scene& scene)
+        : Reader(scene)
+    { }
+
+    ~YAMLReader() { }
+
+    ssize_t read_file(const std::string& filename);
+};
+
+#endif /* __READER_YAML_HH__ */