rhi: Add backing format hint to QRhiRenderBuffer

Task-number: QTBUG-83707
Change-Id: I63548f4ace70af614a2aa082663bb3ae9fbedc25
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

1 files changed, 146 insertions, 138 deletions

diff --git a/src/gui/rhi/qrhimetal.mm b/src/gui/rhi/qrhimetal.mm
index f021e78097..c5afdf63eb 100644
--- a/src/gui/rhi/qrhimetal.mm
+++ b/src/gui/rhi/qrhimetal.mm
@@ -621,9 +621,10 @@ bool QRhiMetal::isDeviceLost() const
 }
 
 QRhiRenderBuffer *QRhiMetal::createRenderBuffer(QRhiRenderBuffer::Type type, const QSize &pixelSize,
-                                                int sampleCount, QRhiRenderBuffer::Flags flags)
+                                                int sampleCount, QRhiRenderBuffer::Flags flags,
+                                                QRhiTexture::Format backingFormatHint)
 {
-    return new QMetalRenderBuffer(this, type, pixelSize, sampleCount, flags);
+    return new QMetalRenderBuffer(this, type, pixelSize, sampleCount, flags, backingFormatHint);
 }
 
 QRhiTexture *QRhiMetal::createTexture(QRhiTexture::Format format, const QSize &pixelSize,
@@ -2232,9 +2233,142 @@ QRhiBuffer::NativeBuffer QMetalBuffer::nativeBuffer()
     return { { &d->buf[0] }, 1 };
 }
 
+static inline MTLPixelFormat toMetalTextureFormat(QRhiTexture::Format format, QRhiTexture::Flags flags)
+{
+    const bool srgb = flags.testFlag(QRhiTexture::sRGB);
+    switch (format) {
+    case QRhiTexture::RGBA8:
+        return srgb ? MTLPixelFormatRGBA8Unorm_sRGB : MTLPixelFormatRGBA8Unorm;
+    case QRhiTexture::BGRA8:
+        return srgb ? MTLPixelFormatBGRA8Unorm_sRGB : MTLPixelFormatBGRA8Unorm;
+    case QRhiTexture::R8:
+#ifdef Q_OS_MACOS
+        return MTLPixelFormatR8Unorm;
+#else
+        return srgb ? MTLPixelFormatR8Unorm_sRGB : MTLPixelFormatR8Unorm;
+#endif
+    case QRhiTexture::R16:
+        return MTLPixelFormatR16Unorm;
+    case QRhiTexture::RED_OR_ALPHA8:
+        return MTLPixelFormatR8Unorm;
+
+    case QRhiTexture::RGBA16F:
+        return MTLPixelFormatRGBA16Float;
+    case QRhiTexture::RGBA32F:
+        return MTLPixelFormatRGBA32Float;
+    case QRhiTexture::R16F:
+        return MTLPixelFormatR16Float;
+    case QRhiTexture::R32F:
+        return MTLPixelFormatR32Float;
+
+    case QRhiTexture::D16:
+#ifdef Q_OS_MACOS
+        return MTLPixelFormatDepth16Unorm;
+#else
+        return MTLPixelFormatDepth32Float;
+#endif
+    case QRhiTexture::D32F:
+        return MTLPixelFormatDepth32Float;
+
+#ifdef Q_OS_MACOS
+    case QRhiTexture::BC1:
+        return srgb ? MTLPixelFormatBC1_RGBA_sRGB : MTLPixelFormatBC1_RGBA;
+    case QRhiTexture::BC2:
+        return srgb ? MTLPixelFormatBC2_RGBA_sRGB : MTLPixelFormatBC2_RGBA;
+    case QRhiTexture::BC3:
+        return srgb ? MTLPixelFormatBC3_RGBA_sRGB : MTLPixelFormatBC3_RGBA;
+    case QRhiTexture::BC4:
+        return MTLPixelFormatBC4_RUnorm;
+    case QRhiTexture::BC5:
+        qWarning("QRhiMetal does not support BC5");
+        return MTLPixelFormatRGBA8Unorm;
+    case QRhiTexture::BC6H:
+        return MTLPixelFormatBC6H_RGBUfloat;
+    case QRhiTexture::BC7:
+        return srgb ? MTLPixelFormatBC7_RGBAUnorm_sRGB : MTLPixelFormatBC7_RGBAUnorm;
+#else
+    case QRhiTexture::BC1:
+    case QRhiTexture::BC2:
+    case QRhiTexture::BC3:
+    case QRhiTexture::BC4:
+    case QRhiTexture::BC5:
+    case QRhiTexture::BC6H:
+    case QRhiTexture::BC7:
+        qWarning("QRhiMetal: BCx compression not supported on this platform");
+        return MTLPixelFormatRGBA8Unorm;
+#endif
+
+#ifndef Q_OS_MACOS
+    case QRhiTexture::ETC2_RGB8:
+        return srgb ? MTLPixelFormatETC2_RGB8_sRGB : MTLPixelFormatETC2_RGB8;
+    case QRhiTexture::ETC2_RGB8A1:
+        return srgb ? MTLPixelFormatETC2_RGB8A1_sRGB : MTLPixelFormatETC2_RGB8A1;
+    case QRhiTexture::ETC2_RGBA8:
+        return srgb ? MTLPixelFormatEAC_RGBA8_sRGB : MTLPixelFormatEAC_RGBA8;
+
+    case QRhiTexture::ASTC_4x4:
+        return srgb ? MTLPixelFormatASTC_4x4_sRGB : MTLPixelFormatASTC_4x4_LDR;
+    case QRhiTexture::ASTC_5x4:
+        return srgb ? MTLPixelFormatASTC_5x4_sRGB : MTLPixelFormatASTC_5x4_LDR;
+    case QRhiTexture::ASTC_5x5:
+        return srgb ? MTLPixelFormatASTC_5x5_sRGB : MTLPixelFormatASTC_5x5_LDR;
+    case QRhiTexture::ASTC_6x5:
+        return srgb ? MTLPixelFormatASTC_6x5_sRGB : MTLPixelFormatASTC_6x5_LDR;
+    case QRhiTexture::ASTC_6x6:
+        return srgb ? MTLPixelFormatASTC_6x6_sRGB : MTLPixelFormatASTC_6x6_LDR;
+    case QRhiTexture::ASTC_8x5:
+        return srgb ? MTLPixelFormatASTC_8x5_sRGB : MTLPixelFormatASTC_8x5_LDR;
+    case QRhiTexture::ASTC_8x6:
+        return srgb ? MTLPixelFormatASTC_8x6_sRGB : MTLPixelFormatASTC_8x6_LDR;
+    case QRhiTexture::ASTC_8x8:
+        return srgb ? MTLPixelFormatASTC_8x8_sRGB : MTLPixelFormatASTC_8x8_LDR;
+    case QRhiTexture::ASTC_10x5:
+        return srgb ? MTLPixelFormatASTC_10x5_sRGB : MTLPixelFormatASTC_10x5_LDR;
+    case QRhiTexture::ASTC_10x6:
+        return srgb ? MTLPixelFormatASTC_10x6_sRGB : MTLPixelFormatASTC_10x6_LDR;
+    case QRhiTexture::ASTC_10x8:
+        return srgb ? MTLPixelFormatASTC_10x8_sRGB : MTLPixelFormatASTC_10x8_LDR;
+    case QRhiTexture::ASTC_10x10:
+        return srgb ? MTLPixelFormatASTC_10x10_sRGB : MTLPixelFormatASTC_10x10_LDR;
+    case QRhiTexture::ASTC_12x10:
+        return srgb ? MTLPixelFormatASTC_12x10_sRGB : MTLPixelFormatASTC_12x10_LDR;
+    case QRhiTexture::ASTC_12x12:
+        return srgb ? MTLPixelFormatASTC_12x12_sRGB : MTLPixelFormatASTC_12x12_LDR;
+#else
+    case QRhiTexture::ETC2_RGB8:
+    case QRhiTexture::ETC2_RGB8A1:
+    case QRhiTexture::ETC2_RGBA8:
+        qWarning("QRhiMetal: ETC2 compression not supported on this platform");
+        return MTLPixelFormatRGBA8Unorm;
+
+    case QRhiTexture::ASTC_4x4:
+    case QRhiTexture::ASTC_5x4:
+    case QRhiTexture::ASTC_5x5:
+    case QRhiTexture::ASTC_6x5:
+    case QRhiTexture::ASTC_6x6:
+    case QRhiTexture::ASTC_8x5:
+    case QRhiTexture::ASTC_8x6:
+    case QRhiTexture::ASTC_8x8:
+    case QRhiTexture::ASTC_10x5:
+    case QRhiTexture::ASTC_10x6:
+    case QRhiTexture::ASTC_10x8:
+    case QRhiTexture::ASTC_10x10:
+    case QRhiTexture::ASTC_12x10:
+    case QRhiTexture::ASTC_12x12:
+        qWarning("QRhiMetal: ASTC compression not supported on this platform");
+        return MTLPixelFormatRGBA8Unorm;
+#endif
+
+    default:
+        Q_UNREACHABLE();
+        return MTLPixelFormatRGBA8Unorm;
+    }
+}
+
 QMetalRenderBuffer::QMetalRenderBuffer(QRhiImplementation *rhi, Type type, const QSize &pixelSize,
-                                       int sampleCount, QRhiRenderBuffer::Flags flags)
-    : QRhiRenderBuffer(rhi, type, pixelSize, sampleCount, flags),
+                                       int sampleCount, QRhiRenderBuffer::Flags flags,
+                                       QRhiTexture::Format backingFormatHint)
+    : QRhiRenderBuffer(rhi, type, pixelSize, sampleCount, flags, backingFormatHint),
       d(new QMetalRenderBufferData)
 {
 }
@@ -2300,7 +2434,10 @@ bool QMetalRenderBuffer::build()
         break;
     case Color:
         desc.storageMode = MTLStorageModePrivate;
-        d->format = MTLPixelFormatRGBA8Unorm;
+        if (m_backingFormatHint != QRhiTexture::UnknownFormat)
+            d->format = toMetalTextureFormat(m_backingFormatHint, {});
+        else
+            d->format = MTLPixelFormatRGBA8Unorm;
         desc.pixelFormat = d->format;
         break;
     default:
@@ -2325,7 +2462,10 @@ bool QMetalRenderBuffer::build()
 
 QRhiTexture::Format QMetalRenderBuffer::backingFormat() const
 {
-    return m_type == Color ? QRhiTexture::RGBA8 : QRhiTexture::UnknownFormat;
+    if (m_backingFormatHint != QRhiTexture::UnknownFormat)
+        return m_backingFormatHint;
+    else
+        return m_type == Color ? QRhiTexture::RGBA8 : QRhiTexture::UnknownFormat;
 }
 
 QMetalTexture::QMetalTexture(QRhiImplementation *rhi, Format format, const QSize &pixelSize,
@@ -2375,138 +2515,6 @@ void QMetalTexture::release()
     rhiD->unregisterResource(this);
 }
 
-static inline MTLPixelFormat toMetalTextureFormat(QRhiTexture::Format format, QRhiTexture::Flags flags)
-{
-    const bool srgb = flags.testFlag(QRhiTexture::sRGB);
-    switch (format) {
-    case QRhiTexture::RGBA8:
-        return srgb ? MTLPixelFormatRGBA8Unorm_sRGB : MTLPixelFormatRGBA8Unorm;
-    case QRhiTexture::BGRA8:
-        return srgb ? MTLPixelFormatBGRA8Unorm_sRGB : MTLPixelFormatBGRA8Unorm;
-    case QRhiTexture::R8:
-#ifdef Q_OS_MACOS
-        return MTLPixelFormatR8Unorm;
-#else
-        return srgb ? MTLPixelFormatR8Unorm_sRGB : MTLPixelFormatR8Unorm;
-#endif
-    case QRhiTexture::R16:
-        return MTLPixelFormatR16Unorm;
-    case QRhiTexture::RED_OR_ALPHA8:
-        return MTLPixelFormatR8Unorm;
-
-    case QRhiTexture::RGBA16F:
-        return MTLPixelFormatRGBA16Float;
-    case QRhiTexture::RGBA32F:
-        return MTLPixelFormatRGBA32Float;
-    case QRhiTexture::R16F:
-        return MTLPixelFormatR16Float;
-    case QRhiTexture::R32F:
-        return MTLPixelFormatR32Float;
-
-    case QRhiTexture::D16:
-#ifdef Q_OS_MACOS
-        return MTLPixelFormatDepth16Unorm;
-#else
-        return MTLPixelFormatDepth32Float;
-#endif
-    case QRhiTexture::D32F:
-        return MTLPixelFormatDepth32Float;
-
-#ifdef Q_OS_MACOS
-    case QRhiTexture::BC1:
-        return srgb ? MTLPixelFormatBC1_RGBA_sRGB : MTLPixelFormatBC1_RGBA;
-    case QRhiTexture::BC2:
-        return srgb ? MTLPixelFormatBC2_RGBA_sRGB : MTLPixelFormatBC2_RGBA;
-    case QRhiTexture::BC3:
-        return srgb ? MTLPixelFormatBC3_RGBA_sRGB : MTLPixelFormatBC3_RGBA;
-    case QRhiTexture::BC4:
-        return MTLPixelFormatBC4_RUnorm;
-    case QRhiTexture::BC5:
-        qWarning("QRhiMetal does not support BC5");
-        return MTLPixelFormatRGBA8Unorm;
-    case QRhiTexture::BC6H:
-        return MTLPixelFormatBC6H_RGBUfloat;
-    case QRhiTexture::BC7:
-        return srgb ? MTLPixelFormatBC7_RGBAUnorm_sRGB : MTLPixelFormatBC7_RGBAUnorm;
-#else
-    case QRhiTexture::BC1:
-    case QRhiTexture::BC2:
-    case QRhiTexture::BC3:
-    case QRhiTexture::BC4:
-    case QRhiTexture::BC5:
-    case QRhiTexture::BC6H:
-    case QRhiTexture::BC7:
-        qWarning("QRhiMetal: BCx compression not supported on this platform");
-        return MTLPixelFormatRGBA8Unorm;
-#endif
-
-#ifndef Q_OS_MACOS
-    case QRhiTexture::ETC2_RGB8:
-        return srgb ? MTLPixelFormatETC2_RGB8_sRGB : MTLPixelFormatETC2_RGB8;
-    case QRhiTexture::ETC2_RGB8A1:
-        return srgb ? MTLPixelFormatETC2_RGB8A1_sRGB : MTLPixelFormatETC2_RGB8A1;
-    case QRhiTexture::ETC2_RGBA8:
-        return srgb ? MTLPixelFormatEAC_RGBA8_sRGB : MTLPixelFormatEAC_RGBA8;
-
-    case QRhiTexture::ASTC_4x4:
-        return srgb ? MTLPixelFormatASTC_4x4_sRGB : MTLPixelFormatASTC_4x4_LDR;
-    case QRhiTexture::ASTC_5x4:
-        return srgb ? MTLPixelFormatASTC_5x4_sRGB : MTLPixelFormatASTC_5x4_LDR;
-    case QRhiTexture::ASTC_5x5:
-        return srgb ? MTLPixelFormatASTC_5x5_sRGB : MTLPixelFormatASTC_5x5_LDR;
-    case QRhiTexture::ASTC_6x5:
-        return srgb ? MTLPixelFormatASTC_6x5_sRGB : MTLPixelFormatASTC_6x5_LDR;
-    case QRhiTexture::ASTC_6x6:
-        return srgb ? MTLPixelFormatASTC_6x6_sRGB : MTLPixelFormatASTC_6x6_LDR;
-    case QRhiTexture::ASTC_8x5:
-        return srgb ? MTLPixelFormatASTC_8x5_sRGB : MTLPixelFormatASTC_8x5_LDR;
-    case QRhiTexture::ASTC_8x6:
-        return srgb ? MTLPixelFormatASTC_8x6_sRGB : MTLPixelFormatASTC_8x6_LDR;
-    case QRhiTexture::ASTC_8x8:
-        return srgb ? MTLPixelFormatASTC_8x8_sRGB : MTLPixelFormatASTC_8x8_LDR;
-    case QRhiTexture::ASTC_10x5:
-        return srgb ? MTLPixelFormatASTC_10x5_sRGB : MTLPixelFormatASTC_10x5_LDR;
-    case QRhiTexture::ASTC_10x6:
-        return srgb ? MTLPixelFormatASTC_10x6_sRGB : MTLPixelFormatASTC_10x6_LDR;
-    case QRhiTexture::ASTC_10x8:
-        return srgb ? MTLPixelFormatASTC_10x8_sRGB : MTLPixelFormatASTC_10x8_LDR;
-    case QRhiTexture::ASTC_10x10:
-        return srgb ? MTLPixelFormatASTC_10x10_sRGB : MTLPixelFormatASTC_10x10_LDR;
-    case QRhiTexture::ASTC_12x10:
-        return srgb ? MTLPixelFormatASTC_12x10_sRGB : MTLPixelFormatASTC_12x10_LDR;
-    case QRhiTexture::ASTC_12x12:
-        return srgb ? MTLPixelFormatASTC_12x12_sRGB : MTLPixelFormatASTC_12x12_LDR;
-#else
-    case QRhiTexture::ETC2_RGB8:
-    case QRhiTexture::ETC2_RGB8A1:
-    case QRhiTexture::ETC2_RGBA8:
-        qWarning("QRhiMetal: ETC2 compression not supported on this platform");
-        return MTLPixelFormatRGBA8Unorm;
-
-    case QRhiTexture::ASTC_4x4:
-    case QRhiTexture::ASTC_5x4:
-    case QRhiTexture::ASTC_5x5:
-    case QRhiTexture::ASTC_6x5:
-    case QRhiTexture::ASTC_6x6:
-    case QRhiTexture::ASTC_8x5:
-    case QRhiTexture::ASTC_8x6:
-    case QRhiTexture::ASTC_8x8:
-    case QRhiTexture::ASTC_10x5:
-    case QRhiTexture::ASTC_10x6:
-    case QRhiTexture::ASTC_10x8:
-    case QRhiTexture::ASTC_10x10:
-    case QRhiTexture::ASTC_12x10:
-    case QRhiTexture::ASTC_12x12:
-        qWarning("QRhiMetal: ASTC compression not supported on this platform");
-        return MTLPixelFormatRGBA8Unorm;
-#endif
-
-    default:
-        Q_UNREACHABLE();
-        return MTLPixelFormatRGBA8Unorm;
-    }
-}
-
 bool QMetalTexture::prepareBuild(QSize *adjustedSize)
 {
     if (d->tex)