shithub: ft²

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More HPC timer edits

--- a/src/ft2_hpc.c

+++ b/src/ft2_hpc.c

@@ -2,7 +2,7 @@

 ** Hardware Performance Counter delay routines by 8bitbubsy.

 **

 ** These are by no means well written, and are made for specific

-** usage cases. There may be soome hackish design choices here.

+** usage cases. There may be some hackish design choices here.

 **

 ** NOTE: hpc_SetDurationInHz() has quite a bit of overhead, so it's

 **       recommended to have one hpcFreq_t counter for each delay value,

@@ -100,15 +100,15 @@

 	return ((uint64_t)resultHi << 32) | resultLo;

 }

-void hpc_SetDurationInHz(hpc_t *hpc, double dHz) // dHz = max 8191.999inf Hz (0.12ms)

+void hpc_SetDurationInHz(hpc_t *hpc, double dHz) // dHz = max 4095.999inf Hz (0.24ms)

 {

 #define BITS_IN_UINT32 32

-	/* 19 = Good compensation between fraction bits and max integer size.

-	** Non-realtime OSes probably can't do a thread delay with such a

-	** high precision (0.12ms) anyway.

+	/* 20 = Good compensation between fraction bits and max integer size.

+	** Most non-realtime OSes probably can't do a thread delay with such a

+	** high precision ( 0.24ms, 1000/(2^(32-20)-1) ) anyway.

 	*/

-#define INPUT_FRAC_BITS 19

+#define INPUT_FRAC_BITS 20

 #define INPUT_FRAC_SCALE (1UL << INPUT_FRAC_BITS)

 #define INPUT_INT_MAX ((1UL << (BITS_IN_UINT32-INPUT_FRAC_BITS))-1)

@@ -125,7 +125,7 @@

 	hpc->resetFrame = ((uint64_t)fpHz * (60 * 30)) / INPUT_FRAC_SCALE; // reset counters every half an hour

 }

-void hpc_SetDurationInMs(hpc_t *hpc, double dMs) // dMs = minimum 0.12208521548 ms

+void hpc_SetDurationInMs(hpc_t *hpc, double dMs) // dMs = minimum 0.2442002442 ms

 {

 	hpc_SetDurationInHz(hpc, 1000.0 / dMs);

 }

--- a/src/ft2_hpc.h

+++ b/src/ft2_hpc.h

@@ -20,8 +20,8 @@

 extern hpcFreq_t hpcFreq;

 void hpc_Init(void);

-void hpc_SetDurationInHz(hpc_t *hpc, double dHz); // dHz = max 8191.999inf Hz (0.12ms)

-void hpc_SetDurationInMs(hpc_t *hpc, double dMs); // dMs = minimum 0.12208521548 ms

+void hpc_SetDurationInHz(hpc_t *hpc, double dHz); // dHz = max 4095.999inf Hz (0.24ms)

+void hpc_SetDurationInMs(hpc_t *hpc, double dMs); // dMs = minimum 0.2442002442 ms

 void hpc_ResetCounters(hpc_t *hpc);

 void hpc_Wait(hpc_t *hpc);