Have gamma mode and bcm bit depth set at compile time rather than in config (#8)

Author: stuartparmenter

components/hub75/Kconfig

@@ -205,30 +205,57 @@ menu "HUB75 RGB LED Matrix Driver"
                 bool "DP3246"
         endchoice
 
-        choice HUB75_BIT_DEPTH
+        choice
             prompt "Bit Depth"
-            default HUB75_BIT_DEPTH_8
+            default DEPTH_8
             help
                 Color bit depth per channel (R/G/B).
 
                 Higher bit depth = better color gradients but slower refresh rate.
+                Changes require full rebuild to regenerate LUT.
 
-                  - 8-bit: 256 levels/channel, 16.7M colors (good balance)
-                  - 10-bit: 1024 levels/channel, 1.07B colors (better gradients)
-                  - 12-bit: 4096 levels/channel, 68.7B colors (best quality)
+                  - 6-bit: 64 levels/channel (fastest refresh)
+                  - 7-bit: 128 levels/channel
+                  - 8-bit: 256 levels/channel (good balance)
+                  - 9-bit: 512 levels/channel
+                  - 10-bit: 1024 levels/channel (recommended)
+                  - 11-bit: 2048 levels/channel
+                  - 12-bit: 4096 levels/channel (best quality)
 
                 Driver auto-adjusts BCM timing to maintain target refresh rate.
 
-            config HUB75_BIT_DEPTH_8
+            config DEPTH_6
+                bool "6-bit (Fastest)"
+
+            config DEPTH_7
+                bool "7-bit"
+
+            config DEPTH_8
                 bool "8-bit (Good Balance)"
 
-            config HUB75_BIT_DEPTH_10
-                bool "10-bit (Better Gradients)"
+            config DEPTH_9
+                bool "9-bit"
+
+            config DEPTH_10
+                bool "10-bit (Recommended)"
 
-            config HUB75_BIT_DEPTH_12
+            config DEPTH_11
+                bool "11-bit"
+
+            config DEPTH_12
                 bool "12-bit (Best Quality)"
         endchoice
 
+        config HUB75_BIT_DEPTH
+            int
+            default 6 if DEPTH_6
+            default 7 if DEPTH_7
+            default 8 if DEPTH_8
+            default 9 if DEPTH_9
+            default 10 if DEPTH_10
+            default 11 if DEPTH_11
+            default 12 if DEPTH_12
+
         choice HUB75_CLOCK_SPEED
             prompt "Output Clock Speed"
             default HUB75_CLK_20MHZ
@@ -614,30 +641,37 @@ menu "HUB75 RGB LED Matrix Driver"
 
     menu "Color"
 
-        choice HUB75_GAMMA_MODE
+        choice
             prompt "Gamma Correction Mode"
-            default HUB75_GAMMA_CIE1931
+            default GAMMA_CIE1931
             help
                 Gamma correction mode for color output.
+                Changes require full rebuild to regenerate LUT.
 
-                - CIE1931: Standard perceptual lightness curve (recommended)
                 - Linear: No gamma correction (1:1 mapping)
-                - None: Alias for Linear
+                - CIE1931: Standard perceptual lightness curve (recommended)
+                - Gamma 2.2: Standard gamma 2.2 correction
 
                 CIE1931 provides better visual color gradients by matching
-                human perception of brightness. Linear/None provides direct
+                human perception of brightness. Linear provides direct
                 hardware mapping but may appear less smooth.
 
-            config HUB75_GAMMA_CIE1931
-                bool "CIE1931 (Perceptual)"
-
-            config HUB75_GAMMA_LINEAR
+            config GAMMA_LINEAR
                 bool "Linear (No Correction)"
 
-            config HUB75_GAMMA_NONE
-                bool "None (Same as Linear)"
+            config GAMMA_CIE1931
+                bool "CIE1931 (Perceptual)"
+
+            config GAMMA_2_2
+                bool "Gamma 2.2"
         endchoice
 
+        config HUB75_GAMMA_MODE
+            int
+            default 0 if GAMMA_LINEAR
+            default 1 if GAMMA_CIE1931
+            default 2 if GAMMA_2_2
+
     endmenu
 
     # ========================================

components/hub75/README.md

@@ -142,10 +142,14 @@ Double buffering doubles memory usage but enables tear-free animation. PARLIO us
 - `uint8_t get_brightness()` - Get current brightness value
 
 **Gamma Correction:**
-Gamma correction mode is set at initialization via `config.gamma_mode` and cannot be changed at runtime:
-- `Hub75GammaMode::NONE` - No gamma correction (linear)
-- `Hub75GammaMode::CIE1931` - CIE 1931 standard (recommended, default)
-- `Hub75GammaMode::GAMMA_2_2` - Gamma 2.2 correction
+Gamma correction mode is **compile-time only** (configured via menuconfig):
+- `HUB75_GAMMA_MODE=0` - Linear (no correction)
+- `HUB75_GAMMA_MODE=1` - CIE 1931 standard (recommended, default)
+- `HUB75_GAMMA_MODE=2` - Gamma 2.2
+
+Configure via:
+- `idf.py menuconfig` → HUB75 → Color → Gamma Correction Mode
+- Or CMake: `target_compile_definitions(app PRIVATE HUB75_GAMMA_MODE=1)`
 
 **Dual-Mode Brightness System:**
 - **Basis brightness** (0-255): Adjusts hardware OE (output enable) timing in DMA buffers
@@ -180,11 +184,18 @@ config.layout = PanelLayout::HORIZONTAL;
 
 **Higher quality display:**
 ```cpp
-config.bit_depth = 10;         // Better gradients
+// Bit depth: Configure via menuconfig (6-12 bit available)
+// (idf.py menuconfig → HUB75 → Panel Settings → Bit Depth)
 config.double_buffer = true;   // Tear-free updates
 config.min_refresh_rate = 90;  // Smoother for cameras
 ```
 
+**Bit Depth Configuration:**
+Bit depth is **compile-time only** (6-12 bits supported):
+- Configure via `idf.py menuconfig` → HUB75 → Panel Settings → Bit Depth
+- Or CMake: `target_compile_definitions(app PRIVATE HUB75_BIT_DEPTH=10)`
+- Changes require full rebuild (regenerates LUT at compile time)
+
 **For complete configuration reference** (all scan patterns, layouts, clock speeds, bit depth options, pin configuration, etc.), see **[MENUCONFIG.md](../../docs/MENUCONFIG.md)**.
 
 ## Multi-Panel Layouts

components/hub75/include/hub75_config.h

@@ -54,6 +54,30 @@ extern "C" {
 #define HUB75_MAX_CHAINED_PANELS 8
 #endif
 
+/**
+ * Bit depth configuration (6-12 bits)
+ * Set via menuconfig or override: -DHUB75_BIT_DEPTH=10
+ */
+#ifndef HUB75_BIT_DEPTH
+#ifdef CONFIG_HUB75_BIT_DEPTH
+#define HUB75_BIT_DEPTH CONFIG_HUB75_BIT_DEPTH
+#else
+#define HUB75_BIT_DEPTH 8  // Default if no Kconfig
+#endif
+#endif
+
+/**
+ * Gamma mode (0=LINEAR/NONE, 1=CIE1931, 2=GAMMA_2_2)
+ * Set via menuconfig or override: -DHUB75_GAMMA_MODE=1
+ */
+#ifndef HUB75_GAMMA_MODE
+#ifdef CONFIG_HUB75_GAMMA_MODE
+#define HUB75_GAMMA_MODE CONFIG_HUB75_GAMMA_MODE
+#else
+#define HUB75_GAMMA_MODE 1  // Default: CIE1931
+#endif
+#endif
+
 #ifdef __cplusplus
 }
 #endif

components/hub75/include/hub75_types.h

@@ -13,15 +13,6 @@
 extern "C" {
 #endif
 
-/**
- * @brief Gamma correction mode
- */
-enum class Hub75GammaMode {
-  NONE = 0,   // No gamma correction (linear)
-  CIE1931,    // CIE 1931 perceptual correction
-  GAMMA_2_2,  // Standard gamma 2.2
-};
-
 /**
  * @brief Pixel buffer format for bulk drawing operations
  */
@@ -197,7 +188,6 @@ struct Hub75Config {
   // ========================================
 
   Hub75ClockSpeed output_clock_speed = Hub75ClockSpeed::HZ_20M;  // Output clock speed (default: 20MHz)
-  uint8_t bit_depth = 8;                                         // BCM bit depth: 6-12 (default: 8)
   uint16_t min_refresh_rate = 60;                                // Minimum refresh rate in Hz (default: 60)
 
   // ========================================
@@ -218,8 +208,7 @@ struct Hub75Config {
   // Color
   // ========================================
 
-  Hub75GammaMode gamma_mode = Hub75GammaMode::CIE1931;  // Gamma correction mode (default: CIE1931)
-  uint8_t brightness = 128;                             // Initial brightness 0-255 (default: 128)
+  uint8_t brightness = 128;  // Initial brightness 0-255 (default: 128)
 };
 
 #ifdef __cplusplus