From 99bef0f362bd7f7027d718ff2d8524852e036594 Mon Sep 17 00:00:00 2001
From: Adam Honse <calcprogrammer1@gmail.com>
Date: Thu, 3 Feb 2022 15:35:47 -0600
Subject: [PATCH] Speed up Direct mode by only sending the necessary portion of
 the packet

---
 .../GigabyteRGBFusion2DRAMController.cpp      | 46 ++++++++++++++++++-
 .../GigabyteRGBFusion2DRAMController.h        |  1 +
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/Controllers/GigabyteRGBFusion2DRAMController/GigabyteRGBFusion2DRAMController.cpp b/Controllers/GigabyteRGBFusion2DRAMController/GigabyteRGBFusion2DRAMController.cpp
index 18eda93b1..ab2622424 100644
--- a/Controllers/GigabyteRGBFusion2DRAMController/GigabyteRGBFusion2DRAMController.cpp
+++ b/Controllers/GigabyteRGBFusion2DRAMController/GigabyteRGBFusion2DRAMController.cpp
@@ -32,6 +32,8 @@ RGBFusion2DRAMController::RGBFusion2DRAMController(i2c_smbus_interface* bus, rgb
     \*-----------------------------------------------------*/
     led_count = 6;
 
+    direct_initialized = false;
+
     /*-----------------------------------------------------*\
     | Initialize brightness to 100%                         |
     \*-----------------------------------------------------*/
@@ -73,21 +75,54 @@ void RGBFusion2DRAMController::SetLEDEffect
     unsigned char   blue
     )
 {
+    bool truncate_packet = false;
+
     if(mode == RGB_FUSION_2_DRAM_MODE_DIRECT)
     {
+        /*-----------------------------------------------------*\
+        | In Direct mode, set one LED at a time                 |
+        \*-----------------------------------------------------*/
         led_data[RGB_FUSION_2_DRAM_LED_EN_MASK] = (1 << led);
 
-        // hack for direct mode
+        /*-----------------------------------------------------*\
+        | Hack for Direct mode                                  |
+        \*-----------------------------------------------------*/
         led_data[16] = 1;
         led_data[22] = 2;
         led_data[29] = 1;
         led_data[30] = 1;
 
+        /*-----------------------------------------------------*\
+        | If bytes 15-31 have already been set, we can speed up |
+        | repeat direct mode packets by only sending the portion|
+        | that changes, in this case bytes 0-14.  If direct mode|
+        | has already been initialized, truncate the packet by  |
+        | only sending the first 15 bytes.                      |
+        \*-----------------------------------------------------*/
+        if(direct_initialized)
+        {
+            truncate_packet = true;
+        }
+
+        direct_initialized = true;
+
+        /*-----------------------------------------------------*\
+        | Direct mode is implemented using Pulse mode           |
+        \*-----------------------------------------------------*/
         mode = RGB_FUSION_2_DRAM_MODE_PULSE;
     }
     else
     {
+        /*-----------------------------------------------------*\
+        | In all other modes, set all LEDs at once              |
+        \*-----------------------------------------------------*/
         led_data[RGB_FUSION_2_DRAM_LED_EN_MASK] = 0x3F;
+
+        /*-----------------------------------------------------*\
+        | Clear direct mode initialized flag when setting a non-|
+        | Direct mode                                           |
+        \*-----------------------------------------------------*/
+        direct_initialized = false;
     }
 
     led_data[RGB_FUSION_2_DRAM_IDX_MODE]        = mode;
@@ -95,7 +130,14 @@ void RGBFusion2DRAMController::SetLEDEffect
     led_data[RGB_FUSION_2_DRAM_IDX_GREEN]       = green;
     led_data[RGB_FUSION_2_DRAM_IDX_BLUE]        = blue;
 
-    bus->i2c_smbus_write_block_data(dev, RGB_FUSION_2_DRAM_LED_START_ADDR, 32, led_data);
+    if(truncate_packet)
+    {
+        bus->i2c_smbus_write_block_data(dev, RGB_FUSION_2_DRAM_LED_START_ADDR, 15, led_data);
+    }
+    else
+    {
+        bus->i2c_smbus_write_block_data(dev, RGB_FUSION_2_DRAM_LED_START_ADDR, 32, led_data);
+    }
 
     Apply();
 }
diff --git a/Controllers/GigabyteRGBFusion2DRAMController/GigabyteRGBFusion2DRAMController.h b/Controllers/GigabyteRGBFusion2DRAMController/GigabyteRGBFusion2DRAMController.h
index 61afec547..62b82d5b7 100644
--- a/Controllers/GigabyteRGBFusion2DRAMController/GigabyteRGBFusion2DRAMController.h
+++ b/Controllers/GigabyteRGBFusion2DRAMController/GigabyteRGBFusion2DRAMController.h
@@ -76,6 +76,7 @@ private:
     unsigned int            led_count;
     i2c_smbus_interface*    bus;
     rgb_fusion_dev_id       dev;
+    bool                    direct_initialized;
 
     unsigned char           led_data[32];
 };