+ * Read a cropped texture from the instrument's property list.
+ *
+ * The x1 and y1 properties give the starting position of the texture
+ * (between 0.0 and 1.0), and the the x2 and y2 properties give the
+ * ending position. For example, to use the bottom-left quarter of a
+ * texture, x1=0.0, y1=0.0, x2=0.5, y2=0.5.
+ */
+static FGCroppedTexture
+readTexture (const SGPropertyNode * node)
+{
+ FGCroppedTexture texture(node->getStringValue("path"),
+ node->getFloatValue("x1"),
+ node->getFloatValue("y1"),
+ node->getFloatValue("x2", 1.0),
+ node->getFloatValue("y2", 1.0));
+ FG_LOG(FG_INPUT, FG_INFO, "Read texture " << node->getName());
+ return texture;
+}
+
+
+/**
+ * Read an action from the instrument's property list.
+ *
+ * The action will be performed when the user clicks a mouse button
+ * within the specified region of the instrument. Actions always
+ * work by modifying the value of a property (see the SGValue class).
+ *
+ * The following action types are defined:
+ *
+ * "adjust" - modify the value of a floating-point property by
+ * the increment specified. This is the default.
+ *
+ * "swap" - swap the values of two-floating-point properties.
+ *
+ * "toggle" - toggle the value of a boolean property between true and
+ * false.
+ *
+ * For the adjust action, it is possible to specify an increment
+ * (use a negative number for a decrement), a minimum allowed value,
+ * a maximum allowed value, and a flag to indicate whether the value
+ * should freeze or wrap-around when it reachs the minimum or maximum.
+ *
+ * The action will be scaled automatically if the instrument is not
+ * being drawn at its regular size.
+ */
+static FGPanelAction *
+readAction (const SGPropertyNode * node, float hscale, float vscale)
+{
+ FGPanelAction * action = 0;
+
+ string name = node->getStringValue("name");
+ string type = node->getStringValue("type");
+
+ int button = node->getIntValue("button");
+ int x = int(node->getIntValue("x") * hscale);
+ int y = int(node->getIntValue("y") * vscale);
+ int w = int(node->getIntValue("w") * hscale);
+ int h = int(node->getIntValue("h") * vscale);
+
+ if (type == "") {
+ FG_LOG(FG_INPUT, FG_ALERT,
+ "No type supplied for action " << name << " assuming \"adjust\"");
+ type = "adjust";
+ }
+
+ // Adjust a property value
+ if (type == "adjust") {
+ string propName = node->getStringValue("property");
+ SGValue * value = fgGetValue(propName, true);
+ float increment = node->getFloatValue("increment", 1.0);
+ float min = node->getFloatValue("min", 0.0);
+ float max = node->getFloatValue("max", 0.0);
+ bool wrap = node->getBoolValue("wrap", false);
+ if (min == max)
+ FG_LOG(FG_INPUT, FG_ALERT, "Action " << node->getName()
+ << " has same min and max value");
+ action = new FGAdjustAction(button, x, y, w, h, value,
+ increment, min, max, wrap);
+ }
+
+ // Swap two property values
+ else if (type == "swap") {
+ string propName1 = node->getStringValue("property1");
+ string propName2 = node->getStringValue("property2");
+ SGValue * value1 = fgGetValue(propName1, true);
+ SGValue * value2 = fgGetValue(propName2, true);
+ action = new FGSwapAction(button, x, y, w, h, value1, value2);
+ }
+
+ // Toggle a boolean value
+ else if (type == "toggle") {
+ string propName = node->getStringValue("property");
+ SGValue * value = fgGetValue(propName, true);
+ action = new FGToggleAction(button, x, y, w, h, value);
+ }
+
+ // Unrecognized type
+ else {
+ FG_LOG(FG_INPUT, FG_ALERT, "Unrecognized action type " << type);
+ return 0;
+ }
+
+ return action;
+}
+
+
+/**
+ * Read a transformation from the instrument's property list.
+ *
+ * The panel module uses the transformations to slide or spin needles,
+ * knobs, and other indicators, and to place layers in the correct
+ * positions. Every layer starts centered exactly on the x,y co-ordinate,
+ * and many layers need to be moved or rotated simply to display the
+ * instrument correctly.
+ *
+ * There are three types of transformations:
+ *
+ * "x-shift" - move the layer horizontally.
+ *
+ * "y-shift" - move the layer vertically.
+ *
+ * "rotation" - rotate the layer.
+ *
+ * Each transformation may have a fixed offset, and may also have
+ * a floating-point property value to add to the offset. The
+ * floating-point property may be clamped to a minimum and/or
+ * maximum range and scaled (after clamping).
+ *
+ * Note that because of the way OpenGL works, transformations will
+ * appear to be applied backwards.
+ */
+static FGPanelTransformation *
+readTransformation (const SGPropertyNode * node, float hscale, float vscale)
+{
+ FGPanelTransformation * t = new FGPanelTransformation;
+
+ string name = node->getName();
+ string type = node->getStringValue("type");
+ string propName = node->getStringValue("property", "");
+ SGValue * value = 0;
+
+ if (type == "") {
+ FG_LOG(FG_INPUT, FG_ALERT,
+ "No type supplied for transformation " << name
+ << " assuming \"rotation\"");
+ type = "rotation";
+ }
+
+ if (propName != (string)"") {
+ value = fgGetValue(propName, true);
+ }
+
+ t->value = value;
+ t->min = node->getFloatValue("min", -9999999);
+ t->max = node->getFloatValue("max", 99999999);
+ t->factor = node->getFloatValue("scale", 1.0);
+ t->offset = node->getFloatValue("offset", 0.0);
+
+ // Move the layer horizontally.
+ if (type == "x-shift") {
+ t->type = FGPanelTransformation::XSHIFT;
+ t->min *= hscale;
+ t->max *= hscale;
+ t->offset *= hscale;
+ }
+
+ // Move the layer vertically.
+ else if (type == "y-shift") {
+ t->type = FGPanelTransformation::YSHIFT;
+ t->min *= vscale;
+ t->max *= vscale;
+ t->offset *= vscale;
+ }
+
+ // Rotate the layer. The rotation
+ // is in degrees, and does not need
+ // to scale with the instrument size.
+ else if (type == "rotation") {
+ t->type = FGPanelTransformation::ROTATION;
+ }
+
+ else {
+ FG_LOG(FG_INPUT, FG_ALERT, "Unrecognized transformation type " << type);
+ delete t;
+ return 0;
+ }
+
+ FG_LOG(FG_INPUT, FG_INFO, "Read transformation " << name);
+ return t;
+}
+
+
+/**
+ * Read a chunk of text from the instrument's property list.
+ *
+ * A text layer consists of one or more chunks of text. All chunks
+ * share the same font size and color (and eventually, font), but
+ * each can come from a different source. There are three types of
+ * text chunks:
+ *
+ * "literal" - a literal text string (the default)
+ *
+ * "text-value" - the current value of a string property
+ *
+ * "number-value" - the current value of a floating-point property.
+ *
+ * All three may also include a printf-style format string.
+ */
+FGTextLayer::Chunk *
+readTextChunk (const SGPropertyNode * node)
+{
+ FGTextLayer::Chunk * chunk;
+ string name = node->getStringValue("name");
+ string type = node->getStringValue("type");
+ string format = node->getStringValue("format");
+
+ // Default to literal text.
+ if (type == "") {
+ FG_LOG(FG_INPUT, FG_INFO, "No type provided for text chunk " << name
+ << " assuming \"literal\"");
+ type = "literal";
+ }
+
+ // A literal text string.
+ if (type == "literal") {
+ string text = node->getStringValue("text");
+ chunk = new FGTextLayer::Chunk(text, format);
+ }
+
+ // The value of a string property.
+ else if (type == "text-value") {
+ SGValue * value =
+ fgGetValue(node->getStringValue("property"), true);
+ chunk = new FGTextLayer::Chunk(FGTextLayer::TEXT_VALUE, value, format);
+ }
+
+ // The value of a float property.
+ else if (type == "number-value") {
+ string propName = node->getStringValue("property");
+ float scale = node->getFloatValue("scale", 1.0);
+ SGValue * value = fgGetValue(propName, true);
+ chunk = new FGTextLayer::Chunk(FGTextLayer::DOUBLE_VALUE, value,
+ format, scale);
+ }
+
+ // Unknown type.
+ else {
+ FG_LOG(FG_INPUT, FG_ALERT, "Unrecognized type " << type
+ << " for text chunk " << name);
+ return 0;
+ }
+
+ return chunk;
+}
+
+
+/**
+ * Read a single layer from an instrument's property list.
+ *
+ * Each instrument consists of one or more layers stacked on top
+ * of each other; the lower layers show through only where the upper
+ * layers contain an alpha component. Each layer can be moved
+ * horizontally and vertically and rotated using transformations.
+ *
+ * This module currently recognizes four kinds of layers:
+ *
+ * "texture" - a layer containing a texture (the default)
+ *
+ * "text" - a layer containing text
+ *
+ * "switch" - a layer that switches between two other layers
+ * based on the current value of a boolean property.
+ *
+ * "built-in" - a hard-coded layer supported by C++ code in FlightGear.
+ *
+ * Currently, the only built-in layer class is "compass-ribbon".
+ */
+static FGInstrumentLayer *
+readLayer (const SGPropertyNode * node, float hscale, float vscale)
+{
+ FGInstrumentLayer * layer = NULL;
+ string name = node->getStringValue("name");
+ string type = node->getStringValue("type");
+ int w = node->getIntValue("w", -1);
+ int h = node->getIntValue("h", -1);
+ if (w != -1)
+ w = int(w * hscale);
+ if (h != -1)
+ h = int(h * vscale);
+
+
+ if (type == "") {
+ FG_LOG(FG_INPUT, FG_ALERT,
+ "No type supplied for layer " << name
+ << " assuming \"texture\"");
+ type = "texture";
+ }
+
+
+ // A textured instrument layer.
+ if (type == "texture") {
+ FGCroppedTexture texture = readTexture(node->getNode("texture"));
+ layer = new FGTexturedLayer(texture, w, h);
+ }
+
+
+ // A textual instrument layer.
+ else if (type == "text") {
+ FGTextLayer * tlayer = new FGTextLayer(w, h); // FIXME
+
+ // Set the text color.
+ float red = node->getFloatValue("color/red", 0.0);
+ float green = node->getFloatValue("color/green", 0.0);
+ float blue = node->getFloatValue("color/blue", 0.0);
+ tlayer->setColor(red, green, blue);
+
+ // Set the point size.
+ float pointSize = node->getFloatValue("point-size", 10.0) * hscale;
+ tlayer->setPointSize(pointSize);
+
+ // Set the font.
+ // TODO
+
+ const SGPropertyNode * chunk_group = node->getNode("chunks");
+ if (chunk_group != 0) {
+ int nChunks = chunk_group->nChildren();
+ for (int i = 0; i < nChunks; i++) {
+ FGTextLayer::Chunk * chunk = readTextChunk(chunk_group->getChild(i));
+ if (chunk == 0) {
+ delete layer;
+ return 0;
+ }
+ tlayer->addChunk(chunk);
+ }
+ layer = tlayer;
+ }
+ }
+
+ // A switch instrument layer.
+ else if (type == "switch") {
+ SGValue * value =
+ fgGetValue(node->getStringValue("property"), true);
+ FGInstrumentLayer * layer1 =
+ readLayer(node->getNode("layer1"), hscale, vscale);
+ FGInstrumentLayer * layer2 =
+ readLayer(node->getNode("layer2"), hscale, vscale);
+ layer = new FGSwitchLayer(w, h, value, layer1, layer2);
+ }
+
+ // A built-in instrument layer.
+ else if (type == "built-in") {
+ string layerclass = node->getStringValue("class");
+
+ if (layerclass == "mag-ribbon") {
+ layer = new FGMagRibbon(w, h);
+ }
+
+ else if (layerclass == "") {
+ FG_LOG(FG_INPUT, FG_ALERT, "No class provided for built-in layer "
+ << name);
+ return 0;
+ }
+
+ else {
+ FG_LOG(FG_INPUT, FG_ALERT, "Unknown built-in layer class "
+ << layerclass);
+ return 0;
+ }
+ }
+
+ // An unknown type.
+ else {
+ FG_LOG(FG_INPUT, FG_ALERT, "Unrecognized layer type " << type);
+ delete layer;
+ return 0;
+ }
+
+ //
+ // Get the transformations for each layer.
+ //
+ const SGPropertyNode * trans_group = node->getNode("transformations");
+ if (trans_group != 0) {
+ int nTransformations = trans_group->nChildren();
+ for (int i = 0; i < nTransformations; i++) {
+ FGPanelTransformation * t = readTransformation(trans_group->getChild(i),
+ hscale, vscale);
+ if (t == 0) {
+ delete layer;
+ return 0;
+ }
+ layer->addTransformation(t);
+ }
+ }
+
+ FG_LOG(FG_INPUT, FG_INFO, "Read layer " << name);
+ return layer;
+}
+
+
+/**
+ * Read an instrument from a property list.
+ *
+ * The instrument consists of a preferred width and height
+ * (the panel may override these), together with a list of layers
+ * and a list of actions to be performed when the user clicks
+ * the mouse over the instrument. All co-ordinates are relative
+ * to the instrument's position, so instruments are fully relocatable;
+ * likewise, co-ordinates for actions and transformations will be
+ * scaled automatically if the instrument is not at its preferred size.
+ */
+static FGPanelInstrument *
+readInstrument (const SGPropertyNode * node, int x, int y,
+ int real_w, int real_h)
+{
+ int w = node->getIntValue("w");
+ int h = node->getIntValue("h");
+ const string &name = node->getStringValue("name");
+
+ float hscale = 1.0;
+ float vscale = 1.0;
+ if (real_w != -1) {
+ hscale = float(real_w) / float(w);
+ w = real_w;
+ }
+ if (real_h != -1) {
+ vscale = float(real_h) / float(h);
+ h = real_h;
+ }
+
+ FG_LOG(FG_INPUT, FG_INFO, "Reading instrument " << name);
+
+ FGLayeredInstrument * instrument =
+ new FGLayeredInstrument(x, y, w, h);
+
+ //
+ // Get the actions for the instrument.
+ //
+ const SGPropertyNode * action_group = node->getNode("actions");
+ if (action_group != 0) {
+ int nActions = action_group->nChildren();
+ for (int i = 0; i < nActions; i++) {
+ FGPanelAction * action = readAction(action_group->getChild(i),
+ hscale, vscale);
+ if (action == 0) {
+ delete instrument;
+ return new DefaultInstrument(x, y, w, h);
+ }
+ instrument->addAction(action);
+ }
+ }
+
+ //
+ // Get the layers for the instrument.
+ //
+ const SGPropertyNode * layer_group = node->getNode("layers");
+ if (layer_group != 0) {
+ int nLayers = layer_group->nChildren();
+ for (int i = 0; i < nLayers; i++) {
+ FGInstrumentLayer * layer = readLayer(layer_group->getChild(i),
+ hscale, vscale);
+ if (layer == 0) {
+ delete instrument;
+ return new DefaultInstrument(x, y, w, h);
+ }
+ instrument->addLayer(layer);
+ }
+ }
+
+ FG_LOG(FG_INPUT, FG_INFO, "Done reading instrument " << name);
+ return instrument;
+}
+
+
+/**
+ * Read a panel from a property list.
+ *
+ * Each panel instrument will appear in its own, separate
+ * property list. The top level simply names the panel and
+ * places the instruments in their appropriate locations (and
+ * optionally resizes them if necessary).