Fix max range, range cursor, and stc range control readouts

CLAUDE.md

@@ -227,9 +227,11 @@ These are knobs on the panel once that is built. Keyboard keys until then
    i for right turn. - uniform is float radiogoniometer;
 8. Maximum Range for all scopes except for chain home, which is fixed. This control
    will not operate for Chain Home. These maximum
-   range selections will be defined for each scope; If you try to go beyond the stated
+   This is a stop control. Each step for for each maximum range for the selected radar.
-   maximum ranges, the control will have no effect; note that the default maximum range would
+   those maximum ranges are in a table in settings.h. If you try to step beyond the top maximum
-   be the highest for that scope; keyboard o for lower; p for higher uniform is float max_range;
+   range for that radar, the step higher will do noting. If yoi try to step beyond the lowest
+   maximum range, the the lower step key will be ignored.
+   keyboard o for stepping lower; p for stepping higher.  uniform is float max_range;
 9. Range Cursor (for ppi scopes, not for a scopes) 
    keyboard a for lower; s for higher - uniform is float range_cursor;
 10. Bearing Cursor (for all ppi scopes; not for a scopes) 

current_build_instructions

@@ -1,4 +1,33 @@
-1. build a stub for each radar that displays it's information in the left panel; then show the settngs of its controls on the status panel. In the main scope, just put the name in that panel. We do not have
+As you know, you have enabled the controls on each radar enough to show that they are working, although
-any workings. This is only for testing the operation of the initialization and management.
+there are no uniform variables yet in the shaders.
 
-2. Set the radar management structure to have all radars fully built and available to enable the operator to go through the radar selection and operating the controls.
+This next step is to correct a mistake I made, especially with the maximum range settings for the radars
+as well as the cursors.
+
+First of all remove the control for the maximum range for the chain home radar. The only range option
+for that is 200 nm. This means removing the control as well as setting the global variable for the
+maximum range for chain home to 200nm. Later on when development starts with chain home, we need to
+have a uniform variable for maximum range.
+
+Here are the changes I need for the controls.
+
+Impliment the step changes for the maximum range and indicate the  maximum range in the text
+status. I changed the maximum range setting to the step setting.
+
+The control for the bearing shouid show the following:
+
+1. Degrees from true north, going clockwise for advance or counterclockwise for keyboard for going
+   down. This is for chain home, ascope marine, and marine traffic control.
+
+2. Degrees from front of boat for the police boat radar, going clockwise for advance or 
+   counterclockwise for keyboard for going
+
+3. Note that clockwise is the direction for bearing going positive.
+
+4. If the  operator goes beyond the meximum of 360 clockwise, we reset to 0 
+   and if the operator goes below 0 counterclockwise, we reset to 360.
+
+
+The control for the range cursor; keep normalized from 0 to 1. However, please take that
+normalized value and convert to actual range using the current max range setting and display
+the actual range in the text status window.

global_data.cpp

@@ -122,10 +122,15 @@ float uniform_noise_filter = 0.0f;
 // Components: Chain Home A-scope
 float uniform_radiogoniometer = 0.0f;
 
-// Maximum radar range (scope-dependent units) — keyboard o (lower) / p (higher)
+/*
-// GLSL uniform: float max_range
+ * Maximum radar range in nautical miles (NOT normalized).
-// Components: Marine A-scope, PPI scopes (not Chain Home; that is fixed)
+ * Chain Home: fixed at CHAIN_HOME_MAX_RANGE_NM; o/p keys ignored.
-float uniform_max_range = 1.0f;
+ * Others: set from the radar's step table when a radar is activated; updated by o/p.
+ * 0.0 is the placeholder before any radar is selected.
+ * GLSL uniform: float max_range
+ * Components: all scope renderers
+ */
+float uniform_max_range = 0.0f;
 
 // Range cursor position (normalized 0-1) — keyboard a (lower) / s (higher)
 // GLSL uniform: float range_cursor

include/02_text_description.h

@@ -78,6 +78,14 @@ public:
     /* Return the rendered pixel width of text at the given scale. */
     float get_text_width(const std::string& text, float scale) const;
 
+    /* Render text at (x, y), wrapping on word boundaries when a line would
+     * exceed max_width pixels. y is decremented by line_height * scale after
+     * each rendered line, including the last. Never breaks within a word. */
+    void render_text_wrapped(const std::string& text,
+                              float x, float& y, float scale,
+                              float max_width, float line_height,
+                              float color_r, float color_g, float color_b);
+
     /* Set the orthographic projection for a viewport of w × h pixels.
      * Call this each time glViewport changes before rendering text. */
     void set_projection(int w, int h);

include/data_structure_and_constants.h

@@ -194,9 +194,14 @@ extern float uniform_noise_filter;
 // Components: Chain Home A-scope
 extern float uniform_radiogoniometer;
 
-// Maximum radar range, all scopes except Chain Home — keyboard o (lower) / p (higher)
+/*
-// GLSL uniform: float max_range
+ * Maximum radar range in nautical miles (NOT normalized).
-// Components: Marine A-scope, PPI scopes
+ * Chain Home is fixed at CHAIN_HOME_MAX_RANGE_NM; the o/p keys have no effect for it.
+ * For other radars the value is taken from the radar's step table and updated by o/p.
+ * Set via reset_radar_controls() when a radar is activated.
+ * GLSL uniform: float max_range
+ * Components: all scope renderers
+ */
 extern float uniform_max_range;
 
 // Range cursor, PPI scopes only — keyboard a (lower) / s (higher)

include/settings.h

@@ -86,47 +86,85 @@
  * Component: Chain Home scope (1940s, World War 2)
  * ============================================================ */
 
-// Fixed maximum range in km; the max_range control has no effect for this scope
+// Fixed maximum range in nautical miles; the o/p range control has no effect for this scope
-#define CHAIN_HOME_MAX_RANGE_KM 200.0f
+#define CHAIN_HOME_MAX_RANGE_NM 200.0f
 
 /* ============================================================
  * MARINE A-SCOPE
  * Component: 1940s marine A-scope (pre-PPI)
  * ============================================================ */
 
-// Selectable maximum range steps in nautical miles (o/p keys cycle through these)
+// Selectable maximum range steps in nautical miles (o/p keys step through these)
-#define MARINE_A_SCOPE_NUM_RANGES   4
+#define MARINE_A_SCOPE_NUM_RANGES    4
 #define MARINE_A_SCOPE_RANGE_STEP_1  3.0f
 #define MARINE_A_SCOPE_RANGE_STEP_2  6.0f
 #define MARINE_A_SCOPE_RANGE_STEP_3 12.0f
 #define MARINE_A_SCOPE_RANGE_STEP_4 24.0f
 
+// Pip spacing on the A-scope sweep (nm between range pips), one value per range step
+#define MARINE_A_SCOPE_PIP_STEP_1   0.5f   /* 3 nm range  — pip every 0.5 nm */
+#define MARINE_A_SCOPE_PIP_STEP_2   1.0f   /* 6 nm range  — pip every 1.0 nm */
+#define MARINE_A_SCOPE_PIP_STEP_3   2.0f   /* 12 nm range — pip every 2.0 nm */
+#define MARINE_A_SCOPE_PIP_STEP_4   4.0f   /* 24 nm range — pip every 4.0 nm */
+
 /* ============================================================
  * PPI SCOPE - MARINE TRAFFIC CONTROL
  * Component: PPI scope, marine traffic control station
  * ============================================================ */
 
 // Selectable maximum range steps in nautical miles
-#define PPI_MTC_NUM_RANGES   5
+#define PPI_MTC_NUM_RANGES    5
 #define PPI_MTC_RANGE_STEP_1  3.0f
 #define PPI_MTC_RANGE_STEP_2  6.0f
 #define PPI_MTC_RANGE_STEP_3 12.0f
 #define PPI_MTC_RANGE_STEP_4 24.0f
 #define PPI_MTC_RANGE_STEP_5 48.0f
 
+/*
+ * Range ring positions (nm from centre) per range step.
+ * Two rings per step, placed at 1/3 and 2/3 of the maximum range.
+ * No ring at the maximum range itself — that is the scope edge / graticule boundary.
+ */
+#define PPI_MTC_RING1_STEP_1   1.0f   /* 3 nm  — inner ring */
+#define PPI_MTC_RING2_STEP_1   2.0f   /* 3 nm  — outer ring */
+#define PPI_MTC_RING1_STEP_2   2.0f   /* 6 nm  */
+#define PPI_MTC_RING2_STEP_2   4.0f
+#define PPI_MTC_RING1_STEP_3   4.0f   /* 12 nm */
+#define PPI_MTC_RING2_STEP_3   8.0f
+#define PPI_MTC_RING1_STEP_4   8.0f   /* 24 nm */
+#define PPI_MTC_RING2_STEP_4  16.0f
+#define PPI_MTC_RING1_STEP_5  16.0f   /* 48 nm */
+#define PPI_MTC_RING2_STEP_5  32.0f
+
 /* ============================================================
  * PPI SCOPE - ON-BOARD BOAT
  * Component: PPI scope, on-board boat view
  * ============================================================ */
 
 // Selectable maximum range steps in nautical miles
-#define PPI_BOAT_NUM_RANGES   5
+#define PPI_BOAT_NUM_RANGES    5
 #define PPI_BOAT_RANGE_STEP_1  1.5f
 #define PPI_BOAT_RANGE_STEP_2  3.0f
 #define PPI_BOAT_RANGE_STEP_3  6.0f
 #define PPI_BOAT_RANGE_STEP_4 12.0f
 #define PPI_BOAT_RANGE_STEP_5 24.0f
 
+/*
+ * Range ring positions (nm from centre) per range step.
+ * Two rings per step, placed at 1/3 and 2/3 of the maximum range.
+ * No ring at the maximum range itself — that is the scope edge / graticule boundary.
+ */
+#define PPI_BOAT_RING1_STEP_1   0.5f  /* 1.5 nm — inner ring */
+#define PPI_BOAT_RING2_STEP_1   1.0f  /* 1.5 nm — outer ring */
+#define PPI_BOAT_RING1_STEP_2   1.0f  /* 3 nm   */
+#define PPI_BOAT_RING2_STEP_2   2.0f
+#define PPI_BOAT_RING1_STEP_3   2.0f  /* 6 nm   */
+#define PPI_BOAT_RING2_STEP_3   4.0f
+#define PPI_BOAT_RING1_STEP_4   4.0f  /* 12 nm  */
+#define PPI_BOAT_RING2_STEP_4   8.0f
+#define PPI_BOAT_RING1_STEP_5   8.0f  /* 24 nm  */
+#define PPI_BOAT_RING2_STEP_5  16.0f
+
 /* ============================================================
  * WINDOW AND PANEL LAYOUT
  * Component: Thread 1 (main.cpp), 01_classes, 02_text_description
@@ -198,7 +236,7 @@
 #define BEARING_CURSOR_STEP     1.0f
 #define RANGE_CURSOR_STEP       0.02f
 #define MARINE_A_BEARING_STEP   1.0f
-#define MAX_RANGE_STEP          0.1f
+// Max range is now step-indexed (see MARINE_A_SCOPE_*, PPI_MTC_*, PPI_BOAT_* tables above)
 
 /* ============================================================
  * KEYBOARD CONTROL LIMITS
@@ -217,5 +255,4 @@
 #define NOISE_FILTER_MAX     1.0f
 #define RANGE_CURSOR_MIN     0.0f
 #define RANGE_CURSOR_MAX     1.0f
-#define MAX_RANGE_MIN        0.1f
+// Max range limits removed — range is now step-indexed, clamped by table size
-#define MAX_RANGE_MAX        1.0f

src/01_classes.cpp

@@ -80,6 +80,14 @@ static void text_line(const std::string& text, float x, float& y,
     y -= LH * scale;
 }
 
+/* Render a body-text line with word wrapping; y advances by one line per
+ * wrapped output line. max_width is the available horizontal pixel span. */
+static void text_line_wrapped(const std::string& text, float x, float& y,
+                               float scale, float max_width,
+                               float cr, float cg, float cb) {
+    g_text_renderer.render_text_wrapped(text, x, y, scale, max_width, LH, cr, cg, cb);
+}
+
 /* Render one title-size line using the large renderer at scale 1.0. */
 static void text_line_large(const std::string& text, float x, float& y,
                               float cr, float cg, float cb) {
@@ -151,12 +159,12 @@ static void render_scope_name(const std::string& radar_name) {
 static void render_common_status(float x, float& y, float scale) {
     char buf[320];
     snprintf(buf, sizeof(buf),
-             "Intensity: %.2f  |  Sensitivity: %.2f  |  STC Sens: %.2f  |  STC Range: %.2f",
+             "Intensity: %.2f  |  Sensitivity: %.2f  |  STC Sens: %.2f  |  STC Range: %.1f nm",
              uniform_intensity, uniform_sensitivity,
-             uniform_stc_sensitivity, uniform_stc_range);
+             uniform_stc_sensitivity, uniform_stc_range * uniform_max_range);
-    g_text_renderer.render_text(buf, x, y, scale,
+    float max_w = static_cast<float>(LEFT_PANEL_WIDTH) - 2.0f * MARGIN;
-                                 COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+    text_line_wrapped(buf, x, y, scale, max_w,
-    y -= LH * scale;
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 }
 
 /* ================================================================== */
@@ -221,16 +229,18 @@ void ChainHomeRadar::render_scope() {
 void ChainHomeRadar::render_status_bar() {
     float x = MARGIN;
     float y = static_cast<float>(STATUS_BAR_HEIGHT) - MARGIN - LH;
+    float max_w = static_cast<float>(LEFT_PANEL_WIDTH) - 2.0f * MARGIN;
 
-    text_line("CHAIN HOME RADAR  (Ventnor, Isle of Wight)  |  Fixed range: 200 km",
+    text_line_wrapped("CHAIN HOME RADAR  (Ventnor, Isle of Wight)  |  Fixed range: 200 nm",
-              x, y, SCALE_NORMAL, COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+                      x, y, SCALE_NORMAL, max_w,
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 
     render_common_status(x, y, SCALE_NORMAL);
 
     char buf[200];
     snprintf(buf, sizeof(buf), "Radiogoniometer: %.1f deg", uniform_radiogoniometer);
-    g_text_renderer.render_text(buf, x, y, SCALE_NORMAL,
+    text_line_wrapped(buf, x, y, SCALE_NORMAL, max_w,
-                                 COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 }
 
 /* ================================================================== */
@@ -291,18 +301,20 @@ void MarineAScopeRadar::render_scope() {
 void MarineAScopeRadar::render_status_bar() {
     float x = MARGIN;
     float y = static_cast<float>(STATUS_BAR_HEIGHT) - MARGIN - LH;
+    float max_w = static_cast<float>(LEFT_PANEL_WIDTH) - 2.0f * MARGIN;
 
-    text_line("MARINE A-SCOPE RADAR  (Community Boating Center, Bellingham Bay)",
+    text_line_wrapped("MARINE A-SCOPE RADAR  (Community Boating Center, Bellingham Bay)",
-              x, y, SCALE_NORMAL, COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+                      x, y, SCALE_NORMAL, max_w,
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 
     render_common_status(x, y, SCALE_NORMAL);
 
     char buf[200];
     snprintf(buf, sizeof(buf),
-             "Max Range (normalized): %.2f  |  Antenna Bearing: %.1f deg",
+             "Max Range: %.1f nm  |  Antenna Bearing: %.1f deg",
              uniform_max_range, uniform_marine_a_bearing);
-    g_text_renderer.render_text(buf, x, y, SCALE_NORMAL,
+    text_line_wrapped(buf, x, y, SCALE_NORMAL, max_w,
-                                 COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 }
 
 /* ================================================================== */
@@ -365,20 +377,22 @@ void MarineTrafficRadar::render_scope() {
 void MarineTrafficRadar::render_status_bar() {
     float x = MARGIN;
     float y = static_cast<float>(STATUS_BAR_HEIGHT) - MARGIN - LH;
+    float max_w = static_cast<float>(LEFT_PANEL_WIDTH) - 2.0f * MARGIN;
 
-    text_line("MARINE TRAFFIC CONTROL RADAR  (Bellingham Bay)",
+    text_line_wrapped("MARINE TRAFFIC CONTROL RADAR  (Bellingham Bay)",
-              x, y, SCALE_NORMAL, COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+                      x, y, SCALE_NORMAL, max_w,
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 
     render_common_status(x, y, SCALE_NORMAL);
 
     char buf[280];
     snprintf(buf, sizeof(buf),
-             "Noise Filter: %.2f  |  Max Range (norm): %.2f  |  "
+             "Noise Filter: %.2f  |  Max Range: %.1f nm  |  "
-             "Range Cursor: %.2f  |  Bearing Cursor: %.1f deg",
+             "Range Cursor: %.2f nm  |  Bearing Cursor: %.1f deg",
              uniform_noise_filter, uniform_max_range,
-             uniform_range_cursor, uniform_bearing_cursor);
+             uniform_range_cursor * uniform_max_range, uniform_bearing_cursor);
-    g_text_renderer.render_text(buf, x, y, SCALE_NORMAL,
+    text_line_wrapped(buf, x, y, SCALE_NORMAL, max_w,
-                                 COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 }
 
 /* ================================================================== */
@@ -443,18 +457,20 @@ void PoliceboatRadar::render_scope() {
 void PoliceboatRadar::render_status_bar() {
     float x = MARGIN;
     float y = static_cast<float>(STATUS_BAR_HEIGHT) - MARGIN - LH;
+    float max_w = static_cast<float>(LEFT_PANEL_WIDTH) - 2.0f * MARGIN;
 
-    text_line("POLICE BOAT RADAR  (Bellingham Bay - moving)",
+    text_line_wrapped("POLICE BOAT RADAR  (Bellingham Bay - moving)",
-              x, y, SCALE_NORMAL, COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+                      x, y, SCALE_NORMAL, max_w,
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 
     render_common_status(x, y, SCALE_NORMAL);
 
     char buf[280];
     snprintf(buf, sizeof(buf),
-             "Noise Filter: %.2f  |  Max Range (norm): %.2f  |  "
+             "Noise Filter: %.2f  |  Max Range: %.1f nm  |  "
-             "Range Cursor: %.2f  |  Bearing Cursor: %.1f deg",
+             "Range Cursor: %.2f nm  |  Bearing Cursor: %.1f deg",
              uniform_noise_filter, uniform_max_range,
-             uniform_range_cursor, uniform_bearing_cursor);
+             uniform_range_cursor * uniform_max_range, uniform_bearing_cursor);
-    g_text_renderer.render_text(buf, x, y, SCALE_NORMAL,
+    text_line_wrapped(buf, x, y, SCALE_NORMAL, max_w,
-                                 COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
+                      COL_YELLOW[0], COL_YELLOW[1], COL_YELLOW[2]);
 }

src/02_text_description.cpp

@@ -247,6 +247,38 @@ float TextRenderer::get_text_width(const std::string& text, float scale) const {
     return width;
 }
 
+void TextRenderer::render_text_wrapped(const std::string& text,
+                                        float x, float& y, float scale,
+                                        float max_width, float line_height,
+                                        float color_r, float color_g, float color_b) {
+    std::string line;
+    std::string::size_type pos  = 0;
+    std::string::size_type slen = text.length();
+
+    while (pos <= slen) {
+        std::string::size_type nxt = text.find(' ', pos);
+        if (nxt == std::string::npos) nxt = slen;
+
+        std::string word = text.substr(pos, nxt - pos);
+        if (!word.empty()) {
+            std::string candidate = line.empty() ? word : (line + " " + word);
+            if (!line.empty() && get_text_width(candidate, scale) > max_width) {
+                render_text(line, x, y, scale, color_r, color_g, color_b);
+                y -= line_height * scale;
+                line = word;
+            } else {
+                line = candidate;
+            }
+        }
+        pos = nxt + 1;
+    }
+
+    if (!line.empty()) {
+        render_text(line, x, y, scale, color_r, color_g, color_b);
+        y -= line_height * scale;
+    }
+}
+
 void TextRenderer::set_projection(int w, int h) {
     /* Column-major orthographic matrix mapping pixel space [0,w]x[0,h]
      * to NDC. Near=-1, far=1 (depth unused for 2D text). */

src/main.cpp

@@ -57,6 +57,27 @@
 #include <chrono>
 #include <thread>
 
+/* ------------------------------------------------------------------ */
+/* Range step lookup tables                                             */
+/* Mirror the settings.h defines as arrays so the keyboard handler     */
+/* can index them at run time.                                          */
+/* ------------------------------------------------------------------ */
+
+static const float ASCOPE_RANGES[MARINE_A_SCOPE_NUM_RANGES] = {
+    MARINE_A_SCOPE_RANGE_STEP_1, MARINE_A_SCOPE_RANGE_STEP_2,
+    MARINE_A_SCOPE_RANGE_STEP_3, MARINE_A_SCOPE_RANGE_STEP_4
+};
+
+static const float MTC_RANGES[PPI_MTC_NUM_RANGES] = {
+    PPI_MTC_RANGE_STEP_1, PPI_MTC_RANGE_STEP_2, PPI_MTC_RANGE_STEP_3,
+    PPI_MTC_RANGE_STEP_4, PPI_MTC_RANGE_STEP_5
+};
+
+static const float BOAT_RANGES[PPI_BOAT_NUM_RANGES] = {
+    PPI_BOAT_RANGE_STEP_1, PPI_BOAT_RANGE_STEP_2, PPI_BOAT_RANGE_STEP_3,
+    PPI_BOAT_RANGE_STEP_4, PPI_BOAT_RANGE_STEP_5
+};
+
 /* ------------------------------------------------------------------ */
 /* Debug border-box line renderer (DEBUG_DRAW_WINDOW_BORDERS)           */
 /* ------------------------------------------------------------------ */
@@ -242,6 +263,36 @@ static void GLAPIENTRY gl_debug_callback(GLenum /*source*/,
     fprintf(stderr, "[GL %s] %s\n", type_str, message);
 }
 
+/* ------------------------------------------------------------------ */
+/* reset_radar_controls: called when a radar is activated               */
+/* Resets range to the widest step and zeroes the cursors.             */
+/* ------------------------------------------------------------------ */
+
+static void reset_radar_controls(int radar_idx) {
+    switch (radar_idx) {
+        case RADAR_CHAIN_HOME:
+            uniform_max_range = CHAIN_HOME_MAX_RANGE_NM;
+            break;
+        case RADAR_MARINE_ASCOPE:
+            ascope_range_setting = MARINE_A_SCOPE_NUM_RANGES - 1;
+            uniform_max_range    = ASCOPE_RANGES[ascope_range_setting];
+            break;
+        case RADAR_MARINE_TRAFFIC:
+            traffic_control_range_setting = PPI_MTC_NUM_RANGES - 1;
+            uniform_max_range             = MTC_RANGES[traffic_control_range_setting];
+            break;
+        case RADAR_POLICE_BOAT:
+            police_boat_range_setting = PPI_BOAT_NUM_RANGES - 1;
+            uniform_max_range         = BOAT_RANGES[police_boat_range_setting];
+            break;
+        default:
+            uniform_max_range = 0.0f;
+            break;
+    }
+    uniform_range_cursor   = 0.0f;
+    uniform_bearing_cursor = 0.0f;
+}
+
 /* ------------------------------------------------------------------ */
 /* Keyboard callback (Thread 1)                                         */
 /* ------------------------------------------------------------------ */
@@ -267,13 +318,14 @@ static void key_callback(GLFWwindow* window, int key, int /*scancode*/,
                 (g_selection_cursor - 1 + static_cast<int>(g_selectable.size()))
                 % static_cast<int>(g_selectable.size());
         } else if (key == GLFW_KEY_ENTER || key == GLFW_KEY_KP_ENTER) {
-            /* Activate selected radar. */
+            /* Activate selected radar; reset all controls to defaults for that radar. */
             int mi = g_selectable[g_selection_cursor].management_index;
             for (int i = 0; i < RADAR_COUNT; i++) radar_management[i].selected = 0;
             radar_management[mi].selected = 1;
             current_radar   = mi;
             g_active_radar  = g_selectable[g_selection_cursor].instance;
             g_app_state     = AppState::OPERATING;
+            reset_radar_controls(mi);
         }
         return;
     }
@@ -363,17 +415,43 @@ static void key_callback(GLFWwindow* window, int key, int /*scancode*/,
             }
             break;
 
-        /* Max range (all scopes except Chain Home) */
+        /* Max range — step lower (shorter range / zoom in); Chain Home: no effect */
         case GLFW_KEY_O:
-            if (current_radar != RADAR_CHAIN_HOME) {
+            if (current_radar == RADAR_MARINE_ASCOPE) {
-                uniform_max_range = std::max(MAX_RANGE_MIN,
+                if (ascope_range_setting > 0) {
-                                             uniform_max_range - MAX_RANGE_STEP);
+                    ascope_range_setting--;
+                    uniform_max_range = ASCOPE_RANGES[ascope_range_setting];
+                }
+            } else if (current_radar == RADAR_MARINE_TRAFFIC) {
+                if (traffic_control_range_setting > 0) {
+                    traffic_control_range_setting--;
+                    uniform_max_range = MTC_RANGES[traffic_control_range_setting];
+                }
+            } else if (current_radar == RADAR_POLICE_BOAT) {
+                if (police_boat_range_setting > 0) {
+                    police_boat_range_setting--;
+                    uniform_max_range = BOAT_RANGES[police_boat_range_setting];
+                }
             }
             break;
+
+        /* Max range — step higher (longer range / zoom out); Chain Home: no effect */
         case GLFW_KEY_P:
-            if (current_radar != RADAR_CHAIN_HOME) {
+            if (current_radar == RADAR_MARINE_ASCOPE) {
-                uniform_max_range = std::min(MAX_RANGE_MAX,
+                if (ascope_range_setting < MARINE_A_SCOPE_NUM_RANGES - 1) {
-                                             uniform_max_range + MAX_RANGE_STEP);
+                    ascope_range_setting++;
+                    uniform_max_range = ASCOPE_RANGES[ascope_range_setting];
+                }
+            } else if (current_radar == RADAR_MARINE_TRAFFIC) {
+                if (traffic_control_range_setting < PPI_MTC_NUM_RANGES - 1) {
+                    traffic_control_range_setting++;
+                    uniform_max_range = MTC_RANGES[traffic_control_range_setting];
+                }
+            } else if (current_radar == RADAR_POLICE_BOAT) {
+                if (police_boat_range_setting < PPI_BOAT_NUM_RANGES - 1) {
+                    police_boat_range_setting++;
+                    uniform_max_range = BOAT_RANGES[police_boat_range_setting];
+                }
             }
             break;
 
@@ -578,26 +656,33 @@ static void render_radar_list() {
 static void render_selection_status_bar() {
     float x = MARGIN;
     float y = static_cast<float>(STATUS_BAR_HEIGHT) - MARGIN - LH_MAIN;
+    float xp;
 
+    /* Line 1: "Use 1 / 2 to change selection." */
     g_text_renderer.render_text("Use  ", x, y, 1.0f,
                                  COL_WHITE[0], COL_WHITE[1], COL_WHITE[2]);
-    float xp = x + g_text_renderer.get_text_width("Use  ", 1.0f);
+    xp = x + g_text_renderer.get_text_width("Use  ", 1.0f);
 
     g_text_renderer.render_text("1", xp, y, 1.0f,
                                  COL_PINK[0], COL_PINK[1], COL_PINK[2]);
     xp += g_text_renderer.get_text_width("1", 1.0f);
 
-    g_text_renderer.render_text(" / ", xp, y, 1.0f,
+    g_text_renderer.render_text("  /  ", xp, y, 1.0f,
                                  COL_WHITE[0], COL_WHITE[1], COL_WHITE[2]);
-    xp += g_text_renderer.get_text_width(" / ", 1.0f);
+    xp += g_text_renderer.get_text_width("  /  ", 1.0f);
 
     g_text_renderer.render_text("2", xp, y, 1.0f,
                                  COL_PINK[0], COL_PINK[1], COL_PINK[2]);
     xp += g_text_renderer.get_text_width("2", 1.0f);
 
-    g_text_renderer.render_text("  to move the selection.   Press  ", xp, y, 1.0f,
+    g_text_renderer.render_text("  to change selection.", xp, y, 1.0f,
                                  COL_WHITE[0], COL_WHITE[1], COL_WHITE[2]);
-    xp += g_text_renderer.get_text_width("  to move the selection.   Press  ", 1.0f);
+
+    /* Line 2: "Press ENTER to activate." */
+    y -= LH_MAIN;
+    g_text_renderer.render_text("Press  ", x, y, 1.0f,
+                                 COL_WHITE[0], COL_WHITE[1], COL_WHITE[2]);
+    xp = x + g_text_renderer.get_text_width("Press  ", 1.0f);
 
     g_text_renderer.render_text("ENTER", xp, y, 1.0f,
                                  COL_PINK[0], COL_PINK[1], COL_PINK[2]);
@@ -606,13 +691,16 @@ static void render_selection_status_bar() {
     g_text_renderer.render_text("  to activate.", xp, y, 1.0f,
                                  COL_WHITE[0], COL_WHITE[1], COL_WHITE[2]);
 
+    /* Line 3: "Press ESC to exit the exhibit." */
     y -= LH_MAIN;
     g_text_renderer.render_text("Press  ", x, y, 1.0f,
                                  COL_WHITE[0], COL_WHITE[1], COL_WHITE[2]);
     xp = x + g_text_renderer.get_text_width("Press  ", 1.0f);
+
     g_text_renderer.render_text("ESC", xp, y, 1.0f,
                                  COL_PINK[0], COL_PINK[1], COL_PINK[2]);
     xp += g_text_renderer.get_text_width("ESC", 1.0f);
+
     g_text_renderer.render_text("  to exit the exhibit.", xp, y, 1.0f,
                                  COL_WHITE[0], COL_WHITE[1], COL_WHITE[2]);
 }
@@ -827,6 +915,7 @@ int main(int argc, char* argv[]) {
             current_radar  = g_selectable[0].management_index;
             g_active_radar = g_selectable[0].instance;
             g_app_state    = AppState::OPERATING;
+            reset_radar_controls(current_radar);
         }
     }