From 828f0281dd9f0f67a041edea78ab8ba5a8c56279 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ole=20Kr=C3=BCger?= <git@ole.lol>
Date: Sun, 15 Sep 2024 14:17:15 +0100
Subject: [PATCH] Use floats for DPT 8.003, 8.004 and 8.010

---
 knx/dpt/types_8.go      | 44 ++++++++++++++++++++++++-----------------
 knx/dpt/types_8_test.go | 23 +++++++++++----------
 2 files changed, 39 insertions(+), 28 deletions(-)

diff --git a/knx/dpt/types_8.go b/knx/dpt/types_8.go
index 3d5cb06..df20196 100644
--- a/knx/dpt/types_8.go
+++ b/knx/dpt/types_8.go
@@ -5,7 +5,6 @@ package dpt
 
 import (
 	"fmt"
-	"math"
 )
 
 // DPT_8001 represents DPT 8.001 / Counter.
@@ -47,18 +46,21 @@ func (d DPT_8002) String() string {
 }
 
 // DPT_8003 represents DPT 8.003 / delta time ms (range -327.68 s ... 327.67 s)
-type DPT_8003 int32
+type DPT_8003 float32
 
 func (d DPT_8003) Pack() []byte {
-	return packV16(int16(int32(d) / 10))
+	return packV16(int16(d * 100))
 }
 
 func (d *DPT_8003) Unpack(data []byte) error {
-	var i int16
-	if err := unpackV16(data, &i); err != nil {
-		return nil
+	var value int16
+
+	if err := unpackV16(data, &value); err != nil {
+		return err
 	}
-	*d = DPT_8003(int32(i) * 10)
+
+	*d = DPT_8003(float32(value) / 100)
+
 	return nil
 }
 
@@ -71,18 +73,21 @@ func (d DPT_8003) String() string {
 }
 
 // DPT_8004 represents DPT 8.004 / delta time ms (range -3276.8 s ... 3276.7 s)
-type DPT_8004 int32
+type DPT_8004 float32
 
 func (d DPT_8004) Pack() []byte {
-	return packV16(int16(int32(d) / 100))
+	return packV16(int16(d * 10))
 }
 
 func (d *DPT_8004) Unpack(data []byte) error {
-	var i int16
-	if err := unpackV16(data, &i); err != nil {
-		return nil
+	var value int16
+
+	if err := unpackV16(data, &value); err != nil {
+		return err
 	}
-	*d = DPT_8004(int32(i) * 100)
+
+	*d = DPT_8004(float32(value) / 10)
+
 	return nil
 }
 
@@ -155,15 +160,18 @@ func (d DPT_8007) String() string {
 type DPT_8010 float32
 
 func (d DPT_8010) Pack() []byte {
-	return packV16(int16(math.Round(float64(d) / 0.01)))
+	return packV16(int16(d * 100))
 }
 
 func (d *DPT_8010) Unpack(data []byte) error {
-	var i int16
-	if err := unpackV16(data, &i); err != nil {
-		return nil
+	var value int16
+
+	if err := unpackV16(data, &value); err != nil {
+		return err
 	}
-	*d = DPT_8010(float32(i) * 0.01)
+
+	*d = DPT_8010(float32(value) / 100)
+
 	return nil
 }
 
diff --git a/knx/dpt/types_8_test.go b/knx/dpt/types_8_test.go
index 1fc2ae5..a6ef0c0 100644
--- a/knx/dpt/types_8_test.go
+++ b/knx/dpt/types_8_test.go
@@ -59,18 +59,20 @@ func TestDPT_8003(t *testing.T) {
 	var src, dst DPT_8003
 
 	for i := 1; i <= 10; i++ {
-
-		value := int32(rand.Uint32()%math.MaxInt16) * 10
+		value := float32(int16(rand.Int31())) / 100
 
 		// Pack and unpack to test value
 		src = DPT_8003(value)
-		if int32(src) != value {
+
+		if float32(src) != value {
 			t.Errorf("Assignment of value \"%v\" failed for source of type DPT_8003! Has value \"%s\".", value, src)
 		}
+
 		buf = src.Pack()
 		dst.Unpack(buf)
-		if int32(dst) != value {
-			t.Errorf("Value \"%s\" after pack/unpack different from Original value. Was \"%v\"", dst, value)
+
+		if abs(float32(dst)-value) > 0.01 {
+			t.Errorf("Value \"%s\" after pack/unpack different from original value. Was \"%s\"", dst, src)
 		}
 	}
 }
@@ -81,18 +83,19 @@ func TestDPT_8004(t *testing.T) {
 	var src, dst DPT_8004
 
 	for i := 1; i <= 10; i++ {
-
-		value := int32(rand.Uint32()%math.MaxInt16) * 100
+		value := float32(int16(rand.Int31())) / 10
 
 		// Pack and unpack to test value
 		src = DPT_8004(value)
-		if int32(src) != value {
+		if float32(src) != value {
 			t.Errorf("Assignment of value \"%v\" failed for source of type DPT_8003! Has value \"%s\".", value, src)
 		}
+
 		buf = src.Pack()
 		dst.Unpack(buf)
-		if int32(dst) != value {
-			t.Errorf("Value \"%s\" after pack/unpack different from Original value. Was \"%v\"", dst, value)
+
+		if abs(float32(dst)-value) > 0.1 {
+			t.Errorf("Value \"%s\" after pack/unpack different from original value. Was \"%s\"", dst, src)
 		}
 	}
 }