layers: Add utilities for layer configuration via settings file.

Layers can now call getLayerOption("<option name>") to get layer settings.
File xgl_layer_settings.txt can be used to provide option and value  pairs
to configure a given layer.

Add enums to xglLayer.h to provide a generic ACTION and LEVEl settings for
options in the settings file.

1 files changed, 111 insertions, 0 deletions

diff --git a/layers/layers_config.cpp b/layers/layers_config.cpp
new file mode 100644
index 00000000..2d8ea6dd
--- /dev/null
+++ b/layers/layers_config.cpp
@@ -0,0 +1,111 @@
+/**************************************************************************
+ *
+ * Copyright 2014 Lunarg, Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ **************************************************************************/
+#include <fstream>
+#include <string>
+#include <map>
+#include <string.h>
+#include "layers_config.h"
+
+#define MAX_CHARS_PER_LINE 4096
+
+class ConfigFile
+{
+public:
+    ConfigFile();
+    ~ConfigFile();
+
+    const char *getOption(const std::string &_option);
+private:
+    bool m_fileIsParsed;
+    std::map<std::string, std::string> m_valueMap;
+
+    void parseFile(const char *filename);
+};
+
+static ConfigFile g_configFileObj;
+const char *getLayerOption(const char *_option)
+{
+    std::string option(_option);
+    return g_configFileObj.getOption(_option);
+}
+
+ConfigFile::ConfigFile() : m_fileIsParsed(false)
+{
+}
+
+ConfigFile::~ConfigFile()
+{
+}
+
+const char *ConfigFile::getOption(const std::string &_option)
+{
+    std::map<std::string, std::string>::const_iterator it;
+    if (!m_fileIsParsed)
+    {
+        parseFile("xgl_layer_settings.txt");
+    }
+
+    if ((it = m_valueMap.find(_option)) == m_valueMap.end())
+        return NULL;
+    else
+        return it->second.c_str();
+}
+
+void ConfigFile::parseFile(const char *filename)
+{
+    std::ifstream file;
+    char buf[MAX_CHARS_PER_LINE];
+
+    m_fileIsParsed = true;
+    m_valueMap.clear();
+
+    file.open(filename);
+    if (!file.good())
+        return;
+
+    // read tokens from the file and form option, value pairs
+    file.getline(buf, MAX_CHARS_PER_LINE);
+    while (!file.eof())
+    {
+        char option[512];
+        char value[512];
+
+        char *pComment;
+
+        //discard any comments delimited by '#' in the line
+        pComment = strchr(buf, '#');
+        if (pComment)
+            *pComment = '\0';
+
+        if (sscanf(buf, " %511[^\n\t =] = %511[^\n \t]", option, value) == 2)
+        {
+            std::string optStr(option);
+            std::string valStr(value);
+            m_valueMap[optStr] = valStr;
+        }
+        file.getline(buf, MAX_CHARS_PER_LINE);
+    }
+}
+