Unicorn: Move gamma LUTs to pimoroni_common.

Author: Gadgetoid

common/pimoroni_common.hpp

@@ -78,7 +78,7 @@ namespace pimoroni {
       return to_ms_since_boot(get_absolute_time());
     }
 
-    constexpr uint8_t GAMMA_8BIT[256] = {
+    inline constexpr uint8_t GAMMA_8BIT[256] = {
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2,
       2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5,
@@ -98,7 +98,7 @@ namespace pimoroni {
 
     /* Moved from pico_unicorn.cpp
     v = (uint16_t)(powf((float)(n) / 255.0f, 2.2) * 16383.0f + 0.5f) */
-    constexpr uint16_t GAMMA_14BIT[256] = {
+    inline constexpr uint16_t GAMMA_14BIT[256] = {
       0, 0, 0, 1, 2, 3, 4, 6, 8, 10, 13, 16, 20, 23, 28, 32,
       37, 42, 48, 54, 61, 67, 75, 82, 90, 99, 108, 117, 127, 137, 148, 159,
       170, 182, 195, 207, 221, 234, 249, 263, 278, 294, 310, 326, 343, 361, 379, 397,

drivers/rgbled/rgbled.cmake

@@ -7,4 +7,4 @@ target_sources(rgbled INTERFACE
 target_include_directories(rgbled INTERFACE ${CMAKE_CURRENT_LIST_DIR})
 
 # Pull in pico libraries that we need
-target_link_libraries(rgbled INTERFACE pico_stdlib hardware_pwm)
+target_link_libraries(rgbled INTERFACE pico_stdlib hardware_pwm)

libraries/cosmic_unicorn/cosmic_unicorn.cpp

@@ -38,10 +38,6 @@
 //
 //  .. and back to the start
 
-static uint16_t r_gamma_lut[256] = {0};
-static uint16_t g_gamma_lut[256] = {0};
-static uint16_t b_gamma_lut[256] = {0};
-
 static uint32_t dma_channel;
 static uint32_t dma_ctrl_channel;
 static uint32_t audio_dma_channel;
@@ -122,19 +118,6 @@ namespace pimoroni {
       // Tear down the old GU instance's hardware resources
       partial_teardown();
     }
-
-
-    // create 14-bit gamma luts
-    for(uint16_t v = 0; v < 256; v++) {
-      // gamma correct the provided 0-255 brightness value onto a
-      // 0-65535 range for the pwm counter
-      float r_gamma = 1.8f;
-      r_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, r_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-      float g_gamma = 1.8f;
-      g_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, g_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-      float b_gamma = 1.8f;
-      b_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, b_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-    }
 
     // for each row:
     //   for each bcd frame:
@@ -476,9 +459,9 @@ namespace pimoroni {
     g = (g * this->brightness) >> 8;
     b = (b * this->brightness) >> 8;
 
-    uint16_t gamma_r = r_gamma_lut[r];
-    uint16_t gamma_g = g_gamma_lut[g];
-    uint16_t gamma_b = b_gamma_lut[b];
+    uint16_t gamma_r = GAMMA_14BIT[r];
+    uint16_t gamma_g = GAMMA_14BIT[g];
+    uint16_t gamma_b = GAMMA_14BIT[b];
 
     // for each row:
     //   for each bcd frame:

libraries/cosmic_unicorn/cosmic_unicorn.hpp

@@ -2,6 +2,7 @@
 
 #include "hardware/pio.h"
 #include "pico_graphics.hpp"
+#include "common/pimoroni_common.hpp"
 #include "../pico_synth/pico_synth.hpp"
 
 namespace pimoroni {

libraries/galactic_unicorn/galactic_unicorn.cpp

@@ -38,10 +38,6 @@
 //
 //  .. and back to the start
 
-static uint16_t r_gamma_lut[256] = {0};
-static uint16_t g_gamma_lut[256] = {0};
-static uint16_t b_gamma_lut[256] = {0};
-
 static uint32_t dma_channel;
 static uint32_t dma_ctrl_channel;
 static uint32_t audio_dma_channel;
@@ -122,19 +118,6 @@ namespace pimoroni {
       // Tear down the old GU instance's hardware resources
       partial_teardown();
     }
-
-
-    // create 14-bit gamma luts
-    for(uint16_t v = 0; v < 256; v++) {
-      // gamma correct the provided 0-255 brightness value onto a
-      // 0-65535 range for the pwm counter
-      float r_gamma = 1.8f;
-      r_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, r_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-      float g_gamma = 1.8f;
-      g_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, g_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-      float b_gamma = 1.8f;
-      b_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, b_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-    }
 
     // for each row:
     //   for each bcd frame:
@@ -470,9 +453,9 @@ namespace pimoroni {
     g = (g * this->brightness) >> 8;
     b = (b * this->brightness) >> 8;
 
-    uint16_t gamma_r = r_gamma_lut[r];
-    uint16_t gamma_g = g_gamma_lut[g];
-    uint16_t gamma_b = b_gamma_lut[b];
+    uint16_t gamma_r = GAMMA_14BIT[r];
+    uint16_t gamma_g = GAMMA_14BIT[g];
+    uint16_t gamma_b = GAMMA_14BIT[b];
 
     // for each row:
     //   for each bcd frame:

libraries/galactic_unicorn/galactic_unicorn.hpp

@@ -2,6 +2,7 @@
 
 #include "hardware/pio.h"
 #include "pico_graphics.hpp"
+#include "common/pimoroni_common.hpp"
 #include "../pico_synth/pico_synth.hpp"
 
 namespace pimoroni {

libraries/stellar_unicorn/stellar_unicorn.cpp

@@ -38,10 +38,6 @@
 //
 //  .. and back to the start
 
-static uint16_t r_gamma_lut[256] = {0};
-static uint16_t g_gamma_lut[256] = {0};
-static uint16_t b_gamma_lut[256] = {0};
-
 static uint32_t dma_channel;
 static uint32_t dma_ctrl_channel;
 static uint32_t audio_dma_channel;
@@ -122,19 +118,6 @@ namespace pimoroni {
       // Tear down the old GU instance's hardware resources
       partial_teardown();
     }
-
-
-    // create 14-bit gamma luts
-    for(uint16_t v = 0; v < 256; v++) {
-      // gamma correct the provided 0-255 brightness value onto a
-      // 0-65535 range for the pwm counter
-      float r_gamma = 1.8f;
-      r_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, r_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-      float g_gamma = 1.8f;
-      g_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, g_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-      float b_gamma = 1.8f;
-      b_gamma_lut[v] = (uint16_t)(powf((float)(v) / 255.0f, b_gamma) * (float(1U << (BCD_FRAME_COUNT)) - 1.0f) + 0.5f);
-    }
 
     // for each row:
     //   for each bcd frame:
@@ -467,9 +450,9 @@ namespace pimoroni {
     g = (g * this->brightness) >> 8;
     b = (b * this->brightness) >> 8;
 
-    uint16_t gamma_r = r_gamma_lut[r];
-    uint16_t gamma_g = g_gamma_lut[g];
-    uint16_t gamma_b = b_gamma_lut[b];
+    uint16_t gamma_r = GAMMA_14BIT[r];
+    uint16_t gamma_g = GAMMA_14BIT[g];
+    uint16_t gamma_b = GAMMA_14BIT[b];
 
     // for each row:
     //   for each bcd frame:

libraries/stellar_unicorn/stellar_unicorn.hpp

@@ -2,6 +2,7 @@
 
 #include "hardware/pio.h"
 #include "pico_graphics.hpp"
+#include "common/pimoroni_common.hpp"
 #include "../pico_synth/pico_synth.hpp"
 
 namespace pimoroni {