0.2.2 GAMMA

Author: RobTillaart

libraries/GAMMA/README.md

@@ -31,7 +31,8 @@ The library has a **setGamma(float gamma)** function that allows an application
 to change the gamma value runtime. 
 This allows adjustments that a fixed table does not have.
 
-The class can be used to dump the internal table e.g. to place in PROGMEM.
+The class provides **dump()** to create a table e.g. to place in PROGMEM. 
+Since 0.2.2 the library also has **dumpArray()** to generate a C-style array.
 
 Note: tested on UNO and ESP32 only.
 
@@ -42,38 +43,50 @@ Note: tested on UNO and ESP32 only.
 
 - **GAMMA(uint16_t size = 32)** constructor, gets the size of the internal
 array as parameter. The default for size = 32 as this is a good balance between performance
-and size of the internal array. The size parameter must be in {2, 4, 8, 16, 32, 64, 128, 256 }.
-- **begin()** The array is initialized with a gamma == 2.8 which is an often used value.  
-**begin()** must be called before any other function.
-- **setGamma(float gamma)** calculates and fills the array with new values.
-This can be done runtime so runtime adjustment of gamma mapping.  
-This function takes relative quite some time.
+and size of the internal array. 
+The size parameter must be in {2, 4, 8, 16, 32, 64, 128, 256 }.
+- **~GAMMA()** destructor.
+- **void begin()** The internal array is allocated and initialized with a gamma == 2.8.
+This is an often used value to adjust light to human eye responses.
+Note that **begin()** must be called before any other function.
+- **void setGamma(float gamma)** calculates and fills the array with new values.
+This can be done runtime so runtime adjustment of gamma mapping is possible.  
+This calculation are relative expensive and takes quite some time (depending on size).
+If the array already is calculated for gamma, the calculation will be skipped.
 The parameter **gamma** must be > 0. The value 1 gives an 1:1 mapping.
-- **getGamma()** returns the set gamma value.
-- **operator \[\]** allows the GAMMA object to be accessed as an array.
-like ```x = G[40];``` Makes it easy to switch with a real array.
+- **float getGamma()** returns the set gamma value.
+- **uint8_t operator \[\]** allows the GAMMA object to be accessed as an array.
+like ```x = G[40];``` Makes it easy to switch with a real array. 
+The value returned is in the range 0 .. 255, so the user may need to scale it e.g. to 0.0 - 1.0
 
 
 ### Development functions
 
-- **size()** returns size of the internal array.
-- **distinct()** returns the number of distinct values in the table. 
-Especially with larger internal tables rhere will be duplicate numbers in the table.
-- **dump()** dumps the internal table to Serial. Can be useful to create
-an array in RAM, PROGMEM or wherever.
+- **uint16_t size()** returns size of the internal array.
+This is always a power of 2.
+- **uint16_t distinct()** returns the number of distinct values in the table. 
+Especially with larger internal tables there will be duplicate numbers in the table.
+- **void dump(Stream \*str = &Serial)** dumps the internal table to a stream, default Serial. 
+Useful to create an array in RAM, PROGMEM, EEPROM, in a file or wherever.
+- **void dumpArray(Stream \*str = &Serial)** dumps the internal table to a stream, default Serial, as a C-style array. See example.
 
 
 ## Operation
 
-See example
+See example.
 
 
 ## Future ideas
 
 - improve documentation
 - test other platforms
-- look for optimizations 
+- look for optimizations
+  - getter \[\]
+  - setGamma -> pow() is expensive
+- improvements (0.3.0)
+  - return bool => begin() + setGamma() + dump()?
+  - check \_table != NULL in functions
+  - add gamma<=0 check in setGamma()
 - uint16 version?
-- **dumpAsArray()** - generate a C style array 
 - 
 

libraries/GAMMA/examples/GammaErrorAnalysis/GammaErrorAnalysis.ino

@@ -2,7 +2,6 @@
 //    FILE: GammaErrorAnalysis.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: demo
-//    DATE: 2020-08-08
 
 
 #include "gamma.h"
@@ -24,7 +23,10 @@ volatile int x;
 void setup()
 {
   Serial.begin(115200);
+  Serial.println();
   Serial.println(__FILE__);
+  Serial.print("GAMMA_LIB_VERSION: ");
+  Serial.println(GAMMA_LIB_VERSION);
 
   gt1.begin();
   gt2.begin();

libraries/GAMMA/examples/GammaPerformance/GammaPerformance.ino

@@ -2,7 +2,6 @@
 //    FILE: gammaPerformance.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: demo
-//    DATE: 2020-08-08
 
 
 #include "gamma.h"
@@ -21,7 +20,10 @@ volatile int x;
 void setup()
 {
   Serial.begin(115200);
+  Serial.println();
   Serial.println(__FILE__);
+  Serial.print("GAMMA_LIB_VERSION: ");
+  Serial.println(GAMMA_LIB_VERSION);
 
   gt1.begin();
   gt2.begin();
@@ -99,3 +101,4 @@ void loop()
 
 
 // -- END OF FILE --
+

libraries/GAMMA/examples/GammaPerformance/performance_0.2.1.txt

@@ -0,0 +1,34 @@
+Arduino UNO 
+IDE 1.8.19
+
+GammaPerformance.ino
+GAMMA_LIB_VERSION: 0.2.1
+
+timing in microseconds
+
+SETGAMMA
+SIZE	TIME	TIME per element
+257	85868	334.12
+129	42712	331.10
+65	21200	326.15
+33	10448	316.61
+17	5084	299.06
+
+SETGAMMA II
+SIZE	TIME	TIME per element
+257	12	0.05
+129	8	0.06
+65	4	0.06
+33	8	0.24
+17	8	0.47
+
+GET[]
+SIZE	TIME	TIME per element
+257	356	1.39
+129	876	3.42
+65	1116	4.36
+33	1328	5.19
+17	1524	5.95
+
+
+done...

libraries/GAMMA/examples/GammaPerformance/performance_0.2.2.txt

@@ -0,0 +1,34 @@
+Arduino UNO 
+IDE 1.8.19
+
+GammaPerformance.ino
+GAMMA_LIB_VERSION: 0.2.2
+
+timing in microseconds
+
+SETGAMMA
+SIZE	TIME	TIME per element
+257	85868	334.12
+129	42708	331.07
+65	21200	326.15
+33	10456	316.85
+17	5084	299.06
+
+SETGAMMA II
+SIZE	TIME	TIME per element
+257	16	0.06
+129	8	0.06
+65	8	0.12
+33	4	0.12
+17	8	0.47
+
+GET[]
+SIZE	TIME	TIME per element
+257	360	1.41
+129	872	3.41
+65	1124	4.39
+33	1332	5.20
+17	1520	5.94
+
+
+done...

libraries/GAMMA/examples/gammaFast/gammaFast.ino

@@ -1,9 +1,7 @@
 //
 //    FILE: gammaFast.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.2.0
 // PURPOSE: demo
-//    DATE: 2020-08-08
 
 
 #include "gamma.h"
@@ -42,6 +40,10 @@ int fastGamma(uint8_t idx)
 void setup()
 {
   Serial.begin(115200);
+  Serial.println();
+  Serial.println(__FILE__);
+  Serial.print("GAMMA_LIB_VERSION: ");
+  Serial.println(GAMMA_LIB_VERSION);
 
   gt1.begin();
   gt1.setGamma(2.8);

libraries/GAMMA/examples/gammaTest/gammaTest.ino

@@ -2,7 +2,6 @@
 //    FILE: gammaTest.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: demo
-//    DATE: 2020-08-08
 
 
 #include "gamma.h"
@@ -18,6 +17,10 @@ GAMMA gt5(16);
 void setup()
 {
   Serial.begin(115200);
+  Serial.println();
+  Serial.println(__FILE__);
+  Serial.print("GAMMA_LIB_VERSION: ");
+  Serial.println(GAMMA_LIB_VERSION);
 
   gt1.begin();
   gt2.begin();

libraries/GAMMA/examples/gammaTest2/gammaTest2.ino

@@ -2,7 +2,6 @@
 //    FILE: gammaTest2.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: demo setGamma
-//    DATE: 2020-08-08
 
 // Use Arduino Plotter to see the different curves.
 
@@ -15,7 +14,10 @@ GAMMA gt;  // uses default 32 size
 void setup()
 {
   Serial.begin(115200);
-  Serial.println("gammaTest2.ino");
+  Serial.println();
+  Serial.println(__FILE__);
+  Serial.print("GAMMA_LIB_VERSION: ");
+  Serial.println(GAMMA_LIB_VERSION);
 
   gt.begin();
 

libraries/GAMMA/examples/gamma_dump_array/gamma_dump_array.ino

@@ -0,0 +1,52 @@
+//
+//    FILE: gamma_dump_array.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: demo
+
+
+#include "gamma.h"
+
+
+GAMMA gt1(256);
+GAMMA gt2(128);
+GAMMA gt3(64);
+GAMMA gt4(32);    // default
+GAMMA gt5(16);
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println();
+  Serial.println(__FILE__);
+  Serial.print("GAMMA_LIB_VERSION: ");
+  Serial.println(GAMMA_LIB_VERSION);
+
+  gt1.begin();
+  gt2.begin();
+  gt3.begin();
+  gt4.begin();
+  gt5.begin();
+
+  gt1.setGamma(2.8);
+  gt2.setGamma(2.8);
+  gt3.setGamma(2.8);
+  gt4.setGamma(2.8);
+  gt5.setGamma(2.8);
+
+  gt1.dumpArray();
+  gt2.dumpArray();
+  gt3.dumpArray();
+  gt4.dumpArray();
+  gt5.dumpArray();
+
+  Serial.println("\ndone...\n");
+}
+
+
+void loop()
+{
+}
+
+
+// -- END OF FILE --