Add the rgba float tex formats

These may be used by Q3DS for HDR images (IBL).

src/rhi/qrhi.cpp

@@ -1811,6 +1811,12 @@ QRhiRenderBuffer::QRhiRenderBuffer(QRhiImplementation *rhi, Type type_, const QS
     Regardless of the return value, calling release() is always safe.
  */
 
+/*!
+    \fn QRhiTexture::Format QRhiRenderBuffer::backingFormat() const
+
+    \internal
+ */
+
 /*!
     \class QRhiTexture
     \inmodule QtRhi
@@ -1873,6 +1879,10 @@ QRhiRenderBuffer::QRhiRenderBuffer(QRhiImplementation *rhi, Type type_, const QS
     \value RED_OR_ALPHA8 Either same as R8, or is a similar format with the component swizzled to alpha,
     depending on \l{QRhi::RedOrAlpha8IsRed}{RedOrAlpha8IsRed}.
 
+    \value RGBA16F Four components, 16-bit float per component.
+
+    \value RGBA32F Four components, 32-bit float per component.
+
     \value D16 16-bit depth (normalized unsigned integer)
 
     \value D32 32-bit depth (32-bit float)
@@ -3222,6 +3232,16 @@ void QRhiImplementation::textureFormatInfo(QRhiTexture::Format format, const QSi
     case QRhiTexture::R16:
         bpc = 2;
         break;
+    case QRhiTexture::RED_OR_ALPHA8:
+        bpc = 1;
+        break;
+
+    case QRhiTexture::RGBA16F:
+        bpc = 8;
+        break;
+    case QRhiTexture::RGBA32F:
+        bpc = 16;
+        break;
 
     case QRhiTexture::D16:
         bpc = 2;

src/rhi/qrhi.h

@@ -643,6 +643,9 @@ public:
         R16,
         RED_OR_ALPHA8,
 
+        RGBA16F,
+        RGBA32F,
+
         D16,
         D32,
 

src/rhi/qrhid3d11.cpp

@@ -868,6 +868,11 @@ static inline DXGI_FORMAT toD3DTextureFormat(QRhiTexture::Format format, QRhiTex
     case QRhiTexture::RED_OR_ALPHA8:
         return DXGI_FORMAT_R8_UNORM;
 
+    case QRhiTexture::RGBA16F:
+        return DXGI_FORMAT_R16G16B16A16_FLOAT;
+    case QRhiTexture::RGBA32F:
+        return DXGI_FORMAT_R32G32B32A32_FLOAT;
+
     case QRhiTexture::D16:
         return DXGI_FORMAT_R16_TYPELESS;
     case QRhiTexture::D32:

src/rhi/qrhigles2.cpp

@@ -172,6 +172,14 @@ QT_BEGIN_NAMESPACE
 #define GL_RED                            0x1903
 #endif
 
+#ifndef GL_RGBA32F
+#define GL_RGBA32F                        0x8814
+#endif
+
+#ifndef GL_RGBA16F
+#define GL_RGBA16F                        0x881A
+#endif
+
 #ifndef GL_PRIMITIVE_RESTART_FIXED_INDEX
 #define GL_PRIMITIVE_RESTART_FIXED_INDEX  0x8D69
 #endif
@@ -310,6 +318,8 @@ bool QRhiGles2::create(QRhi::Flags flags)
     caps.r8Format = f->hasOpenGLFeature(QOpenGLFunctions::TextureRGFormats);
     caps.r16Format = f->hasOpenGLExtension(QOpenGLExtensions::Sized16Formats);
 
+    caps.floatFormats = actualFormat.version() >= qMakePair(3, 0);
+
     caps.srgbCapableDefaultFramebuffer = f->hasOpenGLExtension(QOpenGLExtensions::SRGBFrameBuffer);
 
     nativeHandlesStruct.context = ctx;
@@ -468,6 +478,11 @@ bool QRhiGles2::isTextureFormatSupported(QRhiTexture::Format format, QRhiTexture
     case QRhiTexture::R16:
         return caps.r16Format;
 
+    case QRhiTexture::RGBA16F:
+        Q_FALLTHROUGH();
+    case QRhiTexture::RGBA32F:
+        return caps.floatFormats;
+
     default:
         break;
     }
@@ -2045,6 +2060,14 @@ bool QGles2Texture::prepareBuild(QSize *adjustedSize)
             glintformat = GL_ALPHA;
             glformat = GL_ALPHA;
             break;
+        case QRhiTexture::RGBA16F:
+            glintformat = GL_RGBA16F;
+            glformat = GL_RGBA;
+            break;
+        case QRhiTexture::RGBA32F:
+            glintformat = GL_RGBA32F;
+            glformat = GL_RGBA;
+            break;
         default:
             Q_UNREACHABLE();
             glintformat = GL_RGBA;

src/rhi/qrhigles2_p.h

@@ -557,6 +557,7 @@ public:
               bgraInternalFormat(false),
               r8Format(false),
               r16Format(false),
+              floatFormats(false),
               srgbCapableDefaultFramebuffer(false)
         { }
         int maxTextureSize;
@@ -570,6 +571,7 @@ public:
         uint bgraInternalFormat : 1;
         uint r8Format : 1;
         uint r16Format : 1;
+        uint floatFormats : 1;
         uint srgbCapableDefaultFramebuffer : 1;
     } caps;
     bool inFrame = false;

src/rhi/qrhimetal.mm

@@ -1844,6 +1844,11 @@ static inline MTLPixelFormat toMetalTextureFormat(QRhiTexture::Format format, QR
     case QRhiTexture::RED_OR_ALPHA8:
         return MTLPixelFormatR8Unorm;
 
+    case QRhiTexture::RGBA16F:
+        return MTLPixelFormatRGBA16Float;
+    case QRhiTexture::RGBA32F:
+        return MTLPixelFormatRGBA32Float;
+
     case QRhiTexture::D16:
         return MTLPixelFormatDepth16Unorm;
     case QRhiTexture::D32:

src/rhi/qrhivulkan.cpp

@@ -644,6 +644,11 @@ static inline VkFormat toVkTextureFormat(QRhiTexture::Format format, QRhiTexture
     case QRhiTexture::RED_OR_ALPHA8:
         return VK_FORMAT_R8_UNORM;
 
+    case QRhiTexture::RGBA16F:
+        return VK_FORMAT_R16G16B16A16_SFLOAT;
+    case QRhiTexture::RGBA32F:
+        return VK_FORMAT_R32G32B32A32_SFLOAT;
+
     case QRhiTexture::D16:
         return VK_FORMAT_D16_UNORM;
     case QRhiTexture::D32: