QtGui: fix build with GCC 13's support for FP16

Conversion must be explicit from float, but doesn't need to be from int.

qimage.cpp:1915:33: error: converting to ‘qfloat16::NativeType’ {aka ‘_Float16’} from ‘float’ with greater conversion rank [-Werror]

Pick-to: 6.5
Change-Id: Ide4dbd0777a44ed0870efffd17390a0e86f1fd7e
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

4 files changed, 28 insertions, 26 deletions

diff --git a/src/gui/painting/qcolor.cpp b/src/gui/painting/qcolor.cpp
index 9494aa70e2..2af2e8cb6b 100644
--- a/src/gui/painting/qcolor.cpp
+++ b/src/gui/painting/qcolor.cpp
@@ -1483,7 +1483,7 @@ void QColor::setAlpha(int alpha)
     QCOLOR_INT_RANGE_CHECK("QColor::setAlpha", alpha);
     if (cspec == ExtendedRgb) {
         constexpr float f = 1.0f / 255;
-        castF16(ct.argbExtended.alphaF16) = alpha * f;
+        castF16(ct.argbExtended.alphaF16) = qfloat16(alpha * f);
         return;
     }
     ct.argb.alpha = alpha * 0x101;
@@ -1512,7 +1512,7 @@ void QColor::setAlphaF(float alpha)
 {
     QCOLOR_REAL_RANGE_CHECK("QColor::setAlphaF", alpha);
     if (cspec == ExtendedRgb) {
-        castF16(ct.argbExtended.alphaF16) = alpha;
+        castF16(ct.argbExtended.alphaF16) = qfloat16(alpha);
         return;
     }
     float tmp = alpha * USHRT_MAX;
@@ -1630,7 +1630,7 @@ void QColor::setRedF(float red)
     if (cspec == Rgb && red >= 0.0f && red <= 1.0f)
         ct.argb.red = qRound(red * USHRT_MAX);
     else if (cspec == ExtendedRgb)
-        castF16(ct.argbExtended.redF16) = red;
+        castF16(ct.argbExtended.redF16) = qfloat16(red);
     else
         setRgbF(red, greenF(), blueF(), alphaF());
 }
@@ -1662,7 +1662,7 @@ void QColor::setGreenF(float green)
     if (cspec == Rgb && green >= 0.0f && green <= 1.0f)
         ct.argb.green = qRound(green * USHRT_MAX);
     else if (cspec == ExtendedRgb)
-        castF16(ct.argbExtended.greenF16) = green;
+        castF16(ct.argbExtended.greenF16) = qfloat16(green);
     else
         setRgbF(redF(), green, blueF(), alphaF());
 }
@@ -1692,7 +1692,7 @@ void QColor::setBlueF(float blue)
     if (cspec == Rgb && blue >= 0.0f && blue <= 1.0f)
         ct.argb.blue = qRound(blue * USHRT_MAX);
     else if (cspec == ExtendedRgb)
-        castF16(ct.argbExtended.blueF16) = blue;
+        castF16(ct.argbExtended.blueF16) = qfloat16(blue);
     else
         setRgbF(redF(), greenF(), blue, alphaF());
 }
diff --git a/src/gui/painting/qcolortransform.cpp b/src/gui/painting/qcolortransform.cpp
index 698696877b..579d99d09c 100644
--- a/src/gui/painting/qcolortransform.cpp
+++ b/src/gui/painting/qcolortransform.cpp
@@ -237,9 +237,9 @@ QRgbaFloat16 QColorTransform::map(QRgbaFloat16 rgbafp16) const
     c.y = d->colorSpaceIn->trc[1].applyExtended(rgbafp16.g);
     c.z = d->colorSpaceIn->trc[2].applyExtended(rgbafp16.b);
     c = d->colorMatrix.map(c);
-    rgbafp16.r = d->colorSpaceOut->trc[0].applyInverseExtended(c.x);
-    rgbafp16.g = d->colorSpaceOut->trc[1].applyInverseExtended(c.y);
-    rgbafp16.b = d->colorSpaceOut->trc[2].applyInverseExtended(c.z);
+    rgbafp16.r = qfloat16(d->colorSpaceOut->trc[0].applyInverseExtended(c.x));
+    rgbafp16.g = qfloat16(d->colorSpaceOut->trc[1].applyInverseExtended(c.y));
+    rgbafp16.b = qfloat16(d->colorSpaceOut->trc[2].applyInverseExtended(c.z));
     return rgbafp16;
 }
 
diff --git a/src/gui/painting/qpixellayout.cpp b/src/gui/painting/qpixellayout.cpp
index 871fd1014d..b196f48617 100644
--- a/src/gui/painting/qpixellayout.cpp
+++ b/src/gui/painting/qpixellayout.cpp
@@ -2226,7 +2226,7 @@ static void QT_FASTCALL storeRGBX16FFromRGBA32F(uchar *dest, const QRgbaFloat32
     QRgbaFloat16 *d = reinterpret_cast<QRgbaFloat16 *>(dest) + index;
     for (int i = 0; i < count; ++i) {
         auto s = src[i].unpremultiplied();
-        d[i] = QRgbaFloat16{ s.r, s.g, s.b, 1.0f };
+        d[i] = QRgbaFloat16{ qfloat16(s.r), qfloat16(s.g), qfloat16(s.b), qfloat16(1.0f) };
     }
 }
 
@@ -2236,7 +2236,7 @@ static void QT_FASTCALL storeRGBA16FFromRGBA32F(uchar *dest, const QRgbaFloat32
     QRgbaFloat16 *d = reinterpret_cast<QRgbaFloat16 *>(dest) + index;
     for (int i = 0; i < count; ++i) {
         auto s = src[i].unpremultiplied();
-        d[i] = QRgbaFloat16{ s.r, s.g, s.b, s.a };
+        d[i] = QRgbaFloat16{ qfloat16(s.r), qfloat16(s.g), qfloat16(s.b), qfloat16(s.a) };
     }
 }
 
diff --git a/src/gui/painting/qrgbafloat.h b/src/gui/painting/qrgbafloat.h
index a7cd2d70d3..d5ca4cd8c9 100644
--- a/src/gui/painting/qrgbafloat.h
+++ b/src/gui/painting/qrgbafloat.h
@@ -28,21 +28,23 @@ public:
     static constexpr
     QRgbaFloat fromRgba64(quint16 red, quint16 green, quint16 blue, quint16 alpha)
     {
+        constexpr FastType scale = 1.0f / 65535.0f;
         return QRgbaFloat{
-            red   * (1.0f / 65535.0f),
-            green * (1.0f / 65535.0f),
-            blue  * (1.0f / 65535.0f),
-            alpha * (1.0f / 65535.0f) };
+            F(red    * scale),
+            F(green  * scale),
+            F(blue   * scale),
+            F(alpha  * scale) };
     }
 
     static constexpr
     QRgbaFloat fromRgba(quint8 red, quint8 green, quint8 blue, quint8 alpha)
     {
+        constexpr FastType scale = 1.0f / 255.0f;
         return QRgbaFloat{
-            red   * (1.0f / 255.0f),
-            green * (1.0f / 255.0f),
-            blue  * (1.0f / 255.0f),
-            alpha * (1.0f / 255.0f) };
+            F(red    * scale),
+            F(green  * scale),
+            F(blue   * scale),
+            F(alpha  * scale) };
     }
     static constexpr
     QRgbaFloat fromArgb32(uint rgb)
@@ -57,10 +59,10 @@ public:
     constexpr FastType green() const { return g; }
     constexpr FastType blue()  const { return b; }
     constexpr FastType alpha() const { return a; }
-    void setRed(FastType _red)     { r = _red; }
-    void setGreen(FastType _green) { g = _green; }
-    void setBlue(FastType _blue)   { b = _blue; }
-    void setAlpha(FastType _alpha) { a = _alpha; }
+    void setRed(FastType _red)     { r = F(_red); }
+    void setGreen(FastType _green) { g = F(_green); }
+    void setBlue(FastType _blue)   { b = F(_blue); }
+    void setAlpha(FastType _alpha) { a = F(_alpha); }
 
     constexpr FastType redNormalized()   const { return std::clamp(static_cast<FastType>(r), 0.0f, 1.0f); }
     constexpr FastType greenNormalized() const { return std::clamp(static_cast<FastType>(g), 0.0f, 1.0f); }
@@ -87,12 +89,12 @@ public:
     }
     constexpr Q_ALWAYS_INLINE QRgbaFloat unpremultiplied() const
     {
-        if (a <= 0.0f)
-            return QRgbaFloat{0.0f, 0.0f, 0.0f, 0.0f};
-        if (a >= 1.0f)
+        if (a <= F{0.0f})
+            return QRgbaFloat{};    // default-initialization: zeroes
+        if (a >= F{1.0f})
             return *this;
         const FastType ia = 1.0f / a;
-        return QRgbaFloat{r * ia, g * ia, b * ia, a};
+        return QRgbaFloat{F(r * ia), F(g * ia), F(b * ia), F(a)};
     }
     constexpr bool operator==(QRgbaFloat f) const
     {