rhi: Add support for arrays of combined image samplers

Introduces a new QRhiShaderResourceBinding function that takes an array
of texture-sampler pairs. The existing function is also available and is
equivalent to calling the array-based version with array size 1.

It is important to note that for Metal one needs MSL 2.0 for array of
textures, so qsb needs --msl 20 instead of --msl 12 for such shaders.

Comes with an autotest, and also updates all .qsb files for said test
with the latest shadertools.

Task-number: QTBUG-82624
Change-Id: Ibc1973aae826836f16d842c41d6c8403fd7ff876
Reviewed-by: Christian Strømme <christian.stromme@qt.io>

9 files changed, 290 insertions, 168 deletions

diff --git a/src/gui/rhi/qrhi.cpp b/src/gui/rhi/qrhi.cpp
index c805e23ad0..83c1e8eaa2 100644
--- a/src/gui/rhi/qrhi.cpp
+++ b/src/gui/rhi/qrhi.cpp
@@ -2885,16 +2885,57 @@ QRhiShaderResourceBinding QRhiShaderResourceBinding::uniformBufferWithDynamicOff
     \return a shader resource binding for the given binding number, pipeline
     stages, texture, and sampler specified by \a binding, \a stage, \a tex,
     \a sampler.
+
+    \note This function is equivalent to calling sampledTextures() with a
+    \c count of 1.
+
+    \sa sampledTextures()
  */
 QRhiShaderResourceBinding QRhiShaderResourceBinding::sampledTexture(
         int binding, StageFlags stage, QRhiTexture *tex, QRhiSampler *sampler)
 {
+    const TextureAndSampler texSampler = { tex, sampler };
+    return sampledTextures(binding, stage, 1, &texSampler);
+}
+
+/*!
+    \return a shader resource binding for the given binding number, pipeline
+    stages, and the array of texture-sampler pairs specified by \a binding, \a
+    stage, \a count, and \a texSamplers.
+
+    \note \a count must be at least 1, and not larger than 16.
+
+    \note When \a count is 1, this function is equivalent to sampledTexture().
+
+    This function is relevant when arrays of combined image samplers are
+    involved. For example, in GLSL \c{layout(binding = 5) uniform sampler2D
+    shadowMaps[8];} declares an array of combined image samplers. The
+    application is then expected provide a QRhiShaderResourceBinding for
+    binding point 5, set up by calling this function with \a count set to 8 and
+    a valid texture and sampler for each element of the array.
+
+    \warning All elements of the array must be specified. With the above
+    example, the only valid, portable approach is calling this function with a
+    \a count of 8. Additionally, all QRhiTexture and QRhiSampler instances must
+    be valid, meaning nullptr is not an accepted value. This is due to some of
+    the underlying APIs, such as, Vulkan, that require a valid image and
+    sampler object for each element in descriptor arrays. Applications are
+    advised to provide "dummy" samplers and textures if some array elements are
+    not relevant (due to not being accessed in the shader).
+
+    \sa sampledTexture()
+ */
+QRhiShaderResourceBinding QRhiShaderResourceBinding::sampledTextures(
+        int binding, StageFlags stage, int count, const TextureAndSampler *texSamplers)
+{
+    Q_ASSERT(count >= 1 && count <= Data::MAX_TEX_SAMPLER_ARRAY_SIZE);
     QRhiShaderResourceBinding b;
     b.d.binding = binding;
     b.d.stage = stage;
     b.d.type = SampledTexture;
-    b.d.u.stex.tex = tex;
-    b.d.u.stex.sampler = sampler;
+    b.d.u.stex.count = count;
+    for (int i = 0; i < count; ++i)
+        b.d.u.stex.texSamplers[i] = texSamplers[i];
     return b;
 }
 
@@ -3084,10 +3125,14 @@ bool operator==(const QRhiShaderResourceBinding &a, const QRhiShaderResourceBind
         }
         break;
     case QRhiShaderResourceBinding::SampledTexture:
-        if (da->u.stex.tex != db->u.stex.tex
-                || da->u.stex.sampler != db->u.stex.sampler)
-        {
+        if (da->u.stex.count != db->u.stex.count)
             return false;
+        for (int i = 0; i < da->u.stex.count; ++i) {
+            if (da->u.stex.texSamplers[i].tex != db->u.stex.texSamplers[i].tex
+                    || da->u.stex.texSamplers[i].sampler != db->u.stex.texSamplers[i].sampler)
+            {
+                return false;
+            }
         }
         break;
     case QRhiShaderResourceBinding::ImageLoad:
@@ -3162,10 +3207,13 @@ QDebug operator<<(QDebug dbg, const QRhiShaderResourceBinding &b)
                       << ')';
         break;
     case QRhiShaderResourceBinding::SampledTexture:
-        dbg.nospace() << " SampledTexture("
-                      << "texture=" << d->u.stex.tex
-                      << " sampler=" << d->u.stex.sampler
-                      << ')';
+        dbg.nospace() << " SampledTextures("
+                      << "count=" << d->u.stex.count;
+        for (int i = 0; i < d->u.stex.count; ++i) {
+            dbg.nospace() << " texture=" << d->u.stex.texSamplers[i].tex
+                          << " sampler=" << d->u.stex.texSamplers[i].sampler;
+        }
+        dbg.nospace() << ')';
         break;
     case QRhiShaderResourceBinding::ImageLoad:
         dbg.nospace() << " ImageLoad("
diff --git a/src/gui/rhi/qrhi_p.h b/src/gui/rhi/qrhi_p.h
index 17c911a5ff..9d906d7bbd 100644
--- a/src/gui/rhi/qrhi_p.h
+++ b/src/gui/rhi/qrhi_p.h
@@ -348,6 +348,12 @@ public:
 
     static QRhiShaderResourceBinding sampledTexture(int binding, StageFlags stage, QRhiTexture *tex, QRhiSampler *sampler);
 
+    struct TextureAndSampler {
+        QRhiTexture *tex;
+        QRhiSampler *sampler;
+    };
+    static QRhiShaderResourceBinding sampledTextures(int binding, StageFlags stage, int count, const TextureAndSampler *texSamplers);
+
     static QRhiShaderResourceBinding imageLoad(int binding, StageFlags stage, QRhiTexture *tex, int level);
     static QRhiShaderResourceBinding imageStore(int binding, StageFlags stage, QRhiTexture *tex, int level);
     static QRhiShaderResourceBinding imageLoadStore(int binding, StageFlags stage, QRhiTexture *tex, int level);
@@ -370,9 +376,10 @@ public:
             int maybeSize;
             bool hasDynamicOffset;
         };
+        static const int MAX_TEX_SAMPLER_ARRAY_SIZE = 16;
         struct SampledTextureData {
-            QRhiTexture *tex;
-            QRhiSampler *sampler;
+            int count;
+            TextureAndSampler texSamplers[MAX_TEX_SAMPLER_ARRAY_SIZE];
         };
         struct StorageImageData {
             QRhiTexture *tex;
diff --git a/src/gui/rhi/qrhid3d11.cpp b/src/gui/rhi/qrhid3d11.cpp
index 7b583e6fd2..7c53925aca 100644
--- a/src/gui/rhi/qrhid3d11.cpp
+++ b/src/gui/rhi/qrhid3d11.cpp
@@ -627,18 +627,25 @@ void QRhiD3D11::setShaderResources(QRhiCommandBuffer *cb, QRhiShaderResourceBind
             break;
         case QRhiShaderResourceBinding::SampledTexture:
         {
-            QD3D11Texture *texD = QRHI_RES(QD3D11Texture, b->u.stex.tex);
-            QD3D11Sampler *samplerD = QRHI_RES(QD3D11Sampler, b->u.stex.sampler);
-            if (texD->generation != bd.stex.texGeneration
-                    || texD->m_id != bd.stex.texId
-                    || samplerD->generation != bd.stex.samplerGeneration
-                    || samplerD->m_id != bd.stex.samplerId)
-            {
+            const QRhiShaderResourceBinding::Data::SampledTextureData *data = &b->u.stex;
+            if (bd.stex.count != data->count) {
+                bd.stex.count = data->count;
                 srbUpdate = true;
-                bd.stex.texId = texD->m_id;
-                bd.stex.texGeneration = texD->generation;
-                bd.stex.samplerId = samplerD->m_id;
-                bd.stex.samplerGeneration = samplerD->generation;
+            }
+            for (int elem = 0; elem < data->count; ++elem) {
+                QD3D11Texture *texD = QRHI_RES(QD3D11Texture, data->texSamplers[elem].tex);
+                QD3D11Sampler *samplerD = QRHI_RES(QD3D11Sampler, data->texSamplers[elem].sampler);
+                if (texD->generation != bd.stex.d[elem].texGeneration
+                        || texD->m_id != bd.stex.d[elem].texId
+                        || samplerD->generation != bd.stex.d[elem].samplerGeneration
+                        || samplerD->m_id != bd.stex.d[elem].samplerId)
+                {
+                    srbUpdate = true;
+                    bd.stex.d[elem].texId = texD->m_id;
+                    bd.stex.d[elem].texGeneration = texD->generation;
+                    bd.stex.d[elem].samplerId = samplerD->m_id;
+                    bd.stex.d[elem].samplerGeneration = samplerD->generation;
+                }
             }
         }
             break;
@@ -1894,31 +1901,38 @@ void QRhiD3D11::updateShaderResourceBindings(QD3D11ShaderResourceBindings *srbD,
             break;
         case QRhiShaderResourceBinding::SampledTexture:
         {
-            QD3D11Texture *texD = QRHI_RES(QD3D11Texture, b->u.stex.tex);
-            QD3D11Sampler *samplerD = QRHI_RES(QD3D11Sampler, b->u.stex.sampler);
-            bd.stex.texId = texD->m_id;
-            bd.stex.texGeneration = texD->generation;
-            bd.stex.samplerId = samplerD->m_id;
-            bd.stex.samplerGeneration = samplerD->generation;
-            if (b->stage.testFlag(QRhiShaderResourceBinding::VertexStage)) {
-                QPair<int, int> nativeBinding = mapBinding(b->binding, RBM_VERTEX, nativeResourceBindingMaps);
-                if (nativeBinding.first >= 0 && nativeBinding.second >= 0) {
-                    res[RBM_VERTEX].textures.append({ nativeBinding.first, texD->srv });
-                    res[RBM_VERTEX].samplers.append({ nativeBinding.second, samplerD->samplerState });
+            const QRhiShaderResourceBinding::Data::SampledTextureData *data = &b->u.stex;
+            bd.stex.count = data->count;
+            const QPair<int, int> nativeBindingVert = mapBinding(b->binding, RBM_VERTEX, nativeResourceBindingMaps);
+            const QPair<int, int> nativeBindingFrag = mapBinding(b->binding, RBM_FRAGMENT, nativeResourceBindingMaps);
+            const QPair<int, int> nativeBindingComp = mapBinding(b->binding, RBM_COMPUTE, nativeResourceBindingMaps);
+            // if SPIR-V binding b is mapped to tN and sN in HLSL, and it
+            // is an array, then it will use tN, tN+1, tN+2, ..., and sN,
+            // sN+1, sN+2, ...
+            for (int elem = 0; elem < data->count; ++elem) {
+                QD3D11Texture *texD = QRHI_RES(QD3D11Texture, data->texSamplers[elem].tex);
+                QD3D11Sampler *samplerD = QRHI_RES(QD3D11Sampler, data->texSamplers[elem].sampler);
+                bd.stex.d[elem].texId = texD->m_id;
+                bd.stex.d[elem].texGeneration = texD->generation;
+                bd.stex.d[elem].samplerId = samplerD->m_id;
+                bd.stex.d[elem].samplerGeneration = samplerD->generation;
+                if (b->stage.testFlag(QRhiShaderResourceBinding::VertexStage)) {
+                    if (nativeBindingVert.first >= 0 && nativeBindingVert.second >= 0) {
+                        res[RBM_VERTEX].textures.append({ nativeBindingVert.first + elem, texD->srv });
+                        res[RBM_VERTEX].samplers.append({ nativeBindingVert.second + elem, samplerD->samplerState });
+                    }
                 }
-            }
-            if (b->stage.testFlag(QRhiShaderResourceBinding::FragmentStage)) {
-                QPair<int, int> nativeBinding = mapBinding(b->binding, RBM_FRAGMENT, nativeResourceBindingMaps);
-                if (nativeBinding.first >= 0 && nativeBinding.second >= 0) {
-                    res[RBM_FRAGMENT].textures.append({ nativeBinding.first, texD->srv });
-                    res[RBM_FRAGMENT].samplers.append({ nativeBinding.second, samplerD->samplerState });
+                if (b->stage.testFlag(QRhiShaderResourceBinding::FragmentStage)) {
+                    if (nativeBindingFrag.first >= 0 && nativeBindingFrag.second >= 0) {
+                        res[RBM_FRAGMENT].textures.append({ nativeBindingFrag.first + elem, texD->srv });
+                        res[RBM_FRAGMENT].samplers.append({ nativeBindingFrag.second + elem, samplerD->samplerState });
+                    }
                 }
-            }
-            if (b->stage.testFlag(QRhiShaderResourceBinding::ComputeStage)) {
-                QPair<int, int> nativeBinding = mapBinding(b->binding, RBM_COMPUTE, nativeResourceBindingMaps);
-                if (nativeBinding.first >= 0 && nativeBinding.second >= 0) {
-                    res[RBM_COMPUTE].textures.append({ nativeBinding.first, texD->srv });
-                    res[RBM_COMPUTE].samplers.append({ nativeBinding.second, samplerD->samplerState });
+                if (b->stage.testFlag(QRhiShaderResourceBinding::ComputeStage)) {
+                    if (nativeBindingComp.first >= 0 && nativeBindingComp.second >= 0) {
+                        res[RBM_COMPUTE].textures.append({ nativeBindingComp.first + elem, texD->srv });
+                        res[RBM_COMPUTE].samplers.append({ nativeBindingComp.second + elem, samplerD->samplerState });
+                    }
                 }
             }
         }
@@ -3529,11 +3543,15 @@ static pD3DCompile resolveD3DCompile()
 
 static QByteArray compileHlslShaderSource(const QShader &shader, QShader::Variant shaderVariant, QString *error, QShaderKey *usedShaderKey)
 {
-    QShaderCode dxbc = shader.shader({ QShader::DxbcShader, 50, shaderVariant });
-    if (!dxbc.shader().isEmpty())
+    QShaderKey key = { QShader::DxbcShader, 50, shaderVariant };
+    QShaderCode dxbc = shader.shader(key);
+    if (!dxbc.shader().isEmpty()) {
+        if (usedShaderKey)
+            *usedShaderKey = key;
         return dxbc.shader();
+    }
 
-    const QShaderKey key = { QShader::HlslShader, 50, shaderVariant };
+    key = { QShader::HlslShader, 50, shaderVariant };
     QShaderCode hlslSource = shader.shader(key);
     if (hlslSource.shader().isEmpty()) {
         qWarning() << "No HLSL (shader model 5.0) code found in baked shader" << shader;
diff --git a/src/gui/rhi/qrhid3d11_p_p.h b/src/gui/rhi/qrhid3d11_p_p.h
index f749b612b5..33412b8011 100644
--- a/src/gui/rhi/qrhid3d11_p_p.h
+++ b/src/gui/rhi/qrhid3d11_p_p.h
@@ -210,10 +210,13 @@ struct QD3D11ShaderResourceBindings : public QRhiShaderResourceBindings
         uint generation;
     };
     struct BoundSampledTextureData {
-        quint64 texId;
-        uint texGeneration;
-        quint64 samplerId;
-        uint samplerGeneration;
+        int count;
+        struct {
+            quint64 texId;
+            uint texGeneration;
+            quint64 samplerId;
+            uint samplerGeneration;
+        } d[QRhiShaderResourceBinding::Data::MAX_TEX_SAMPLER_ARRAY_SIZE];
     };
     struct BoundStorageImageData {
         quint64 id;
diff --git a/src/gui/rhi/qrhigles2.cpp b/src/gui/rhi/qrhigles2.cpp
index feeb65137a..3ba83464d2 100644
--- a/src/gui/rhi/qrhigles2.cpp
+++ b/src/gui/rhi/qrhigles2.cpp
@@ -919,10 +919,12 @@ void QRhiGles2::setShaderResources(QRhiCommandBuffer *cb, QRhiShaderResourceBind
                 hasDynamicOffsetInSrb = true;
             break;
         case QRhiShaderResourceBinding::SampledTexture:
-            trackedRegisterTexture(&passResTracker,
-                                   QRHI_RES(QGles2Texture, b->u.stex.tex),
-                                   QRhiPassResourceTracker::TexSample,
-                                   QRhiPassResourceTracker::toPassTrackerTextureStage(b->stage));
+            for (int elem = 0; elem < b->u.stex.count; ++elem) {
+                trackedRegisterTexture(&passResTracker,
+                                       QRHI_RES(QGles2Texture, b->u.stex.texSamplers[elem].tex),
+                                       QRhiPassResourceTracker::TexSample,
+                                       QRhiPassResourceTracker::toPassTrackerTextureStage(b->stage));
+            }
             break;
         case QRhiShaderResourceBinding::ImageLoad:
         case QRhiShaderResourceBinding::ImageStore:
@@ -2574,36 +2576,37 @@ void QRhiGles2::bindShaderResources(QRhiGraphicsPipeline *maybeGraphicsPs, QRhiC
             break;
         case QRhiShaderResourceBinding::SampledTexture:
         {
-            QGles2Texture *texD = QRHI_RES(QGles2Texture, b->u.stex.tex);
-            QGles2Sampler *samplerD = QRHI_RES(QGles2Sampler, b->u.stex.sampler);
             QVector<QGles2SamplerDescription> &samplers(maybeGraphicsPs ? QRHI_RES(QGles2GraphicsPipeline, maybeGraphicsPs)->samplers
                                                                         : QRHI_RES(QGles2ComputePipeline, maybeComputePs)->samplers);
-
-            for (QGles2SamplerDescription &sampler : samplers) {
-                if (sampler.binding == b->binding) {
-                    f->glActiveTexture(GL_TEXTURE0 + uint(texUnit));
-                    f->glBindTexture(texD->target, texD->texture);
-
-                    if (texD->samplerState != samplerD->d) {
-                        f->glTexParameteri(texD->target, GL_TEXTURE_MIN_FILTER, GLint(samplerD->d.glminfilter));
-                        f->glTexParameteri(texD->target, GL_TEXTURE_MAG_FILTER, GLint(samplerD->d.glmagfilter));
-                        f->glTexParameteri(texD->target, GL_TEXTURE_WRAP_S, GLint(samplerD->d.glwraps));
-                        f->glTexParameteri(texD->target, GL_TEXTURE_WRAP_T, GLint(samplerD->d.glwrapt));
-                        // 3D textures not supported by GLES 2.0 or by us atm...
-                        //f->glTexParameteri(texD->target, GL_TEXTURE_WRAP_R, samplerD->d.glwrapr);
-                        if (caps.textureCompareMode) {
-                            if (samplerD->d.gltexcomparefunc != GL_NEVER) {
-                                f->glTexParameteri(texD->target, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_REF_TO_TEXTURE);
-                                f->glTexParameteri(texD->target, GL_TEXTURE_COMPARE_FUNC, GLint(samplerD->d.gltexcomparefunc));
-                            } else {
-                                f->glTexParameteri(texD->target, GL_TEXTURE_COMPARE_MODE, GL_NONE);
+            for (int elem = 0; elem < b->u.stex.count; ++elem) {
+                QGles2Texture *texD = QRHI_RES(QGles2Texture, b->u.stex.texSamplers[elem].tex);
+                QGles2Sampler *samplerD = QRHI_RES(QGles2Sampler, b->u.stex.texSamplers[elem].sampler);
+                for (QGles2SamplerDescription &sampler : samplers) {
+                    if (sampler.binding == b->binding) {
+                        f->glActiveTexture(GL_TEXTURE0 + uint(texUnit));
+                        f->glBindTexture(texD->target, texD->texture);
+
+                        if (texD->samplerState != samplerD->d) {
+                            f->glTexParameteri(texD->target, GL_TEXTURE_MIN_FILTER, GLint(samplerD->d.glminfilter));
+                            f->glTexParameteri(texD->target, GL_TEXTURE_MAG_FILTER, GLint(samplerD->d.glmagfilter));
+                            f->glTexParameteri(texD->target, GL_TEXTURE_WRAP_S, GLint(samplerD->d.glwraps));
+                            f->glTexParameteri(texD->target, GL_TEXTURE_WRAP_T, GLint(samplerD->d.glwrapt));
+                            // 3D textures not supported by GLES 2.0 or by us atm...
+                            //f->glTexParameteri(texD->target, GL_TEXTURE_WRAP_R, samplerD->d.glwrapr);
+                            if (caps.textureCompareMode) {
+                                if (samplerD->d.gltexcomparefunc != GL_NEVER) {
+                                    f->glTexParameteri(texD->target, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_REF_TO_TEXTURE);
+                                    f->glTexParameteri(texD->target, GL_TEXTURE_COMPARE_FUNC, GLint(samplerD->d.gltexcomparefunc));
+                                } else {
+                                    f->glTexParameteri(texD->target, GL_TEXTURE_COMPARE_MODE, GL_NONE);
+                                }
                             }
+                            texD->samplerState = samplerD->d;
                         }
-                        texD->samplerState = samplerD->d;
-                    }
 
-                    f->glUniform1i(sampler.glslLocation, texUnit);
-                    ++texUnit;
+                        f->glUniform1i(sampler.glslLocation + elem, texUnit);
+                        ++texUnit;
+                    }
                 }
             }
         }
diff --git a/src/gui/rhi/qrhimetal.mm b/src/gui/rhi/qrhimetal.mm
index 314c58b0b7..0806c8a052 100644
--- a/src/gui/rhi/qrhimetal.mm
+++ b/src/gui/rhi/qrhimetal.mm
@@ -748,30 +748,33 @@ void QRhiMetal::enqueueShaderResourceBindings(QMetalShaderResourceBindings *srbD
             break;
         case QRhiShaderResourceBinding::SampledTexture:
         {
-            QMetalTexture *texD = QRHI_RES(QMetalTexture, b->u.stex.tex);
-            QMetalSampler *samplerD = QRHI_RES(QMetalSampler, b->u.stex.sampler);
-            if (b->stage.testFlag(QRhiShaderResourceBinding::VertexStage)) {
-                const int nativeBindingTexture = mapBinding(b->binding, VERTEX, nativeResourceBindingMaps, BindingType::Texture);
-                const int nativeBindingSampler = mapBinding(b->binding, VERTEX, nativeResourceBindingMaps, BindingType::Sampler);
-                if (nativeBindingTexture >= 0 && nativeBindingSampler >= 0) {
-                    res[VERTEX].textures.append({ nativeBindingTexture, texD->d->tex });
-                    res[VERTEX].samplers.append({ nativeBindingSampler, samplerD->d->samplerState });
+            const QRhiShaderResourceBinding::Data::SampledTextureData *data = &b->u.stex;
+            for (int elem = 0; elem < data->count; ++elem) {
+                QMetalTexture *texD = QRHI_RES(QMetalTexture, b->u.stex.texSamplers[elem].tex);
+                QMetalSampler *samplerD = QRHI_RES(QMetalSampler, b->u.stex.texSamplers[elem].sampler);
+                if (b->stage.testFlag(QRhiShaderResourceBinding::VertexStage)) {
+                    const int nativeBindingTexture = mapBinding(b->binding, VERTEX, nativeResourceBindingMaps, BindingType::Texture);
+                    const int nativeBindingSampler = mapBinding(b->binding, VERTEX, nativeResourceBindingMaps, BindingType::Sampler);
+                    if (nativeBindingTexture >= 0 && nativeBindingSampler >= 0) {
+                        res[VERTEX].textures.append({ nativeBindingTexture + elem, texD->d->tex });
+                        res[VERTEX].samplers.append({ nativeBindingSampler + elem, samplerD->d->samplerState });
+                    }
                 }
-            }
-            if (b->stage.testFlag(QRhiShaderResourceBinding::FragmentStage)) {
-                const int nativeBindingTexture = mapBinding(b->binding, FRAGMENT, nativeResourceBindingMaps, BindingType::Texture);
-                const int nativeBindingSampler = mapBinding(b->binding, FRAGMENT, nativeResourceBindingMaps, BindingType::Sampler);
-                if (nativeBindingTexture >= 0 && nativeBindingSampler >= 0) {
-                    res[FRAGMENT].textures.append({ nativeBindingTexture, texD->d->tex });
-                    res[FRAGMENT].samplers.append({ nativeBindingSampler, samplerD->d->samplerState });
+                if (b->stage.testFlag(QRhiShaderResourceBinding::FragmentStage)) {
+                    const int nativeBindingTexture = mapBinding(b->binding, FRAGMENT, nativeResourceBindingMaps, BindingType::Texture);
+                    const int nativeBindingSampler = mapBinding(b->binding, FRAGMENT, nativeResourceBindingMaps, BindingType::Sampler);
+                    if (nativeBindingTexture >= 0 && nativeBindingSampler >= 0) {
+                        res[FRAGMENT].textures.append({ nativeBindingTexture + elem, texD->d->tex });
+                        res[FRAGMENT].samplers.append({ nativeBindingSampler + elem, samplerD->d->samplerState });
+                    }
                 }
-            }
-            if (b->stage.testFlag(QRhiShaderResourceBinding::ComputeStage)) {
-                const int nativeBindingTexture = mapBinding(b->binding, COMPUTE, nativeResourceBindingMaps, BindingType::Texture);
-                const int nativeBindingSampler = mapBinding(b->binding, COMPUTE, nativeResourceBindingMaps, BindingType::Sampler);
-                if (nativeBindingTexture >= 0 && nativeBindingSampler >= 0) {
-                    res[COMPUTE].textures.append({ nativeBindingTexture, texD->d->tex });
-                    res[COMPUTE].samplers.append({ nativeBindingSampler, samplerD->d->samplerState });
+                if (b->stage.testFlag(QRhiShaderResourceBinding::ComputeStage)) {
+                    const int nativeBindingTexture = mapBinding(b->binding, COMPUTE, nativeResourceBindingMaps, BindingType::Texture);
+                    const int nativeBindingSampler = mapBinding(b->binding, COMPUTE, nativeResourceBindingMaps, BindingType::Sampler);
+                    if (nativeBindingTexture >= 0 && nativeBindingSampler >= 0) {
+                        res[COMPUTE].textures.append({ nativeBindingTexture + elem, texD->d->tex });
+                        res[COMPUTE].samplers.append({ nativeBindingSampler + elem, samplerD->d->samplerState });
+                    }
                 }
             }
         }
@@ -1020,21 +1023,28 @@ void QRhiMetal::setShaderResources(QRhiCommandBuffer *cb, QRhiShaderResourceBind
             break;
         case QRhiShaderResourceBinding::SampledTexture:
         {
-            QMetalTexture *texD = QRHI_RES(QMetalTexture, b->u.stex.tex);
-            QMetalSampler *samplerD = QRHI_RES(QMetalSampler, b->u.stex.sampler);
-            if (texD->generation != bd.stex.texGeneration
-                    || texD->m_id != bd.stex.texId
-                    || samplerD->generation != bd.stex.samplerGeneration
-                    || samplerD->m_id != bd.stex.samplerId)
-            {
+            const QRhiShaderResourceBinding::Data::SampledTextureData *data = &b->u.stex;
+            if (bd.stex.count != data->count) {
+                bd.stex.count = data->count;
                 resNeedsRebind = true;
-                bd.stex.texId = texD->m_id;
-                bd.stex.texGeneration = texD->generation;
-                bd.stex.samplerId = samplerD->m_id;
-                bd.stex.samplerGeneration = samplerD->generation;
             }
-            texD->lastActiveFrameSlot = currentFrameSlot;
-            samplerD->lastActiveFrameSlot = currentFrameSlot;
+            for (int elem = 0; elem < data->count; ++elem) {
+                QMetalTexture *texD = QRHI_RES(QMetalTexture, data->texSamplers[elem].tex);
+                QMetalSampler *samplerD = QRHI_RES(QMetalSampler, data->texSamplers[elem].sampler);
+                if (texD->generation != bd.stex.d[elem].texGeneration
+                        || texD->m_id != bd.stex.d[elem].texId
+                        || samplerD->generation != bd.stex.d[elem].samplerGeneration
+                        || samplerD->m_id != bd.stex.d[elem].samplerId)
+                {
+                    resNeedsRebind = true;
+                    bd.stex.d[elem].texId = texD->m_id;
+                    bd.stex.d[elem].texGeneration = texD->generation;
+                    bd.stex.d[elem].samplerId = samplerD->m_id;
+                    bd.stex.d[elem].samplerGeneration = samplerD->generation;
+                }
+                texD->lastActiveFrameSlot = currentFrameSlot;
+                samplerD->lastActiveFrameSlot = currentFrameSlot;
+            }
         }
             break;
         case QRhiShaderResourceBinding::ImageLoad:
@@ -2981,12 +2991,16 @@ bool QMetalShaderResourceBindings::build()
             break;
         case QRhiShaderResourceBinding::SampledTexture:
         {
-            QMetalTexture *texD = QRHI_RES(QMetalTexture, b->u.stex.tex);
-            QMetalSampler *samplerD = QRHI_RES(QMetalSampler, b->u.stex.sampler);
-            bd.stex.texId = texD->m_id;
-            bd.stex.texGeneration = texD->generation;
-            bd.stex.samplerId = samplerD->m_id;
-            bd.stex.samplerGeneration = samplerD->generation;
+            const QRhiShaderResourceBinding::Data::SampledTextureData *data = &b->u.stex;
+            bd.stex.count = data->count;
+            for (int elem = 0; elem < data->count; ++elem) {
+                QMetalTexture *texD = QRHI_RES(QMetalTexture, data->texSamplers[elem].tex);
+                QMetalSampler *samplerD = QRHI_RES(QMetalSampler, data->texSamplers[elem].sampler);
+                bd.stex.d[elem].texId = texD->m_id;
+                bd.stex.d[elem].texGeneration = texD->generation;
+                bd.stex.d[elem].samplerId = samplerD->m_id;
+                bd.stex.d[elem].samplerGeneration = samplerD->generation;
+            }
         }
             break;
         case QRhiShaderResourceBinding::ImageLoad:
@@ -3241,8 +3255,12 @@ static inline MTLCullMode toMetalCullMode(QRhiGraphicsPipeline::CullMode c)
 id<MTLLibrary> QRhiMetalData::createMetalLib(const QShader &shader, QShader::Variant shaderVariant,
                                              QString *error, QByteArray *entryPoint, QShaderKey *activeKey)
 {
-    QShaderKey key = { QShader::MetalLibShader, 12, shaderVariant };
+    QShaderKey key = { QShader::MetalLibShader, 20, shaderVariant };
     QShaderCode mtllib = shader.shader(key);
+    if (mtllib.shader().isEmpty()) {
+        key.setSourceVersion(12);
+        mtllib = shader.shader(key);
+    }
     if (!mtllib.shader().isEmpty()) {
         dispatch_data_t data = dispatch_data_create(mtllib.shader().constData(),
                                                     size_t(mtllib.shader().size()),
@@ -3261,16 +3279,20 @@ id<MTLLibrary> QRhiMetalData::createMetalLib(const QShader &shader, QShader::Var
         }
     }
 
-    key = { QShader::MslShader, 12, shaderVariant };
+    key = { QShader::MslShader, 20, shaderVariant };
     QShaderCode mslSource = shader.shader(key);
     if (mslSource.shader().isEmpty()) {
-        qWarning() << "No MSL 1.2 code found in baked shader" << shader;
+        key.setSourceVersion(12);
+        mslSource = shader.shader(key);
+    }
+    if (mslSource.shader().isEmpty()) {
+        qWarning() << "No MSL 2.0 or 1.2 code found in baked shader" << shader;
         return nil;
     }
 
     NSString *src = [NSString stringWithUTF8String: mslSource.shader().constData()];
     MTLCompileOptions *opts = [[MTLCompileOptions alloc] init];
-    opts.languageVersion = MTLLanguageVersion1_2;
+    opts.languageVersion = key.sourceVersion() == 20 ? MTLLanguageVersion2_0 : MTLLanguageVersion1_2;
     NSError *err = nil;
     id<MTLLibrary> lib = [dev newLibraryWithSource: src options: opts error: &err];
     [opts release];
diff --git a/src/gui/rhi/qrhimetal_p_p.h b/src/gui/rhi/qrhimetal_p_p.h
index a5af5611a6..cb4b777d88 100644
--- a/src/gui/rhi/qrhimetal_p_p.h
+++ b/src/gui/rhi/qrhimetal_p_p.h
@@ -197,10 +197,13 @@ struct QMetalShaderResourceBindings : public QRhiShaderResourceBindings
         uint generation;
     };
     struct BoundSampledTextureData {
-        quint64 texId;
-        uint texGeneration;
-        quint64 samplerId;
-        uint samplerGeneration;
+        int count;
+        struct {
+            quint64 texId;
+            uint texGeneration;
+            quint64 samplerId;
+            uint samplerGeneration;
+        } d[QRhiShaderResourceBinding::Data::MAX_TEX_SAMPLER_ARRAY_SIZE];
     };
     struct BoundStorageImageData {
         quint64 id;
diff --git a/src/gui/rhi/qrhivulkan.cpp b/src/gui/rhi/qrhivulkan.cpp
index a92c3e14e9..ca913475a5 100644
--- a/src/gui/rhi/qrhivulkan.cpp
+++ b/src/gui/rhi/qrhivulkan.cpp
@@ -2487,7 +2487,8 @@ void QRhiVulkan::updateShaderResourceBindings(QRhiShaderResourceBindings *srb, i
     QVkShaderResourceBindings *srbD = QRHI_RES(QVkShaderResourceBindings, srb);
 
     QVarLengthArray<VkDescriptorBufferInfo, 8> bufferInfos;
-    QVarLengthArray<VkDescriptorImageInfo, 8> imageInfos;
+    using ArrayOfImageDesc = QVarLengthArray<VkDescriptorImageInfo, 8>;
+    QVarLengthArray<ArrayOfImageDesc, 8> imageInfos;
     QVarLengthArray<VkWriteDescriptorSet, 12> writeInfos;
     QVarLengthArray<QPair<int, int>, 12> infoIndices;
 
@@ -2530,17 +2531,22 @@ void QRhiVulkan::updateShaderResourceBindings(QRhiShaderResourceBindings *srb, i
                 break;
             case QRhiShaderResourceBinding::SampledTexture:
             {
-                QVkTexture *texD = QRHI_RES(QVkTexture, b->u.stex.tex);
-                QVkSampler *samplerD = QRHI_RES(QVkSampler, b->u.stex.sampler);
+                const QRhiShaderResourceBinding::Data::SampledTextureData *data = &b->u.stex;
+                writeInfo.descriptorCount = data->count; // arrays of combined image samplers are supported
                 writeInfo.descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
-                bd.stex.texId = texD->m_id;
-                bd.stex.texGeneration = texD->generation;
-                bd.stex.samplerId = samplerD->m_id;
-                bd.stex.samplerGeneration = samplerD->generation;
-                VkDescriptorImageInfo imageInfo;
-                imageInfo.sampler = samplerD->sampler;
-                imageInfo.imageView = texD->imageView;
-                imageInfo.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
+                ArrayOfImageDesc imageInfo(data->count);
+                for (int elem = 0; elem < data->count; ++elem) {
+                    QVkTexture *texD = QRHI_RES(QVkTexture, data->texSamplers[elem].tex);
+                    QVkSampler *samplerD = QRHI_RES(QVkSampler, data->texSamplers[elem].sampler);
+                    bd.stex.d[elem].texId = texD->m_id;
+                    bd.stex.d[elem].texGeneration = texD->generation;
+                    bd.stex.d[elem].samplerId = samplerD->m_id;
+                    bd.stex.d[elem].samplerGeneration = samplerD->generation;
+                    imageInfo[elem].sampler = samplerD->sampler;
+                    imageInfo[elem].imageView = texD->imageView;
+                    imageInfo[elem].imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
+                }
+                bd.stex.count = data->count;
                 imageInfoIndex = imageInfos.count();
                 imageInfos.append(imageInfo);
             }
@@ -2555,10 +2561,10 @@ void QRhiVulkan::updateShaderResourceBindings(QRhiShaderResourceBindings *srb, i
                     writeInfo.descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
                     bd.simage.id = texD->m_id;
                     bd.simage.generation = texD->generation;
-                    VkDescriptorImageInfo imageInfo;
-                    imageInfo.sampler = VK_NULL_HANDLE;
-                    imageInfo.imageView = view;
-                    imageInfo.imageLayout = VK_IMAGE_LAYOUT_GENERAL;
+                    ArrayOfImageDesc imageInfo(1);
+                    imageInfo[0].sampler = VK_NULL_HANDLE;
+                    imageInfo[0].imageView = view;
+                    imageInfo[0].imageLayout = VK_IMAGE_LAYOUT_GENERAL;
                     imageInfoIndex = imageInfos.count();
                     imageInfos.append(imageInfo);
                 }
@@ -2596,7 +2602,7 @@ void QRhiVulkan::updateShaderResourceBindings(QRhiShaderResourceBindings *srb, i
         if (bufferInfoIndex >= 0)
             writeInfos[i].pBufferInfo = &bufferInfos[bufferInfoIndex];
         else if (imageInfoIndex >= 0)
-            writeInfos[i].pImageInfo = &imageInfos[imageInfoIndex];
+            writeInfos[i].pImageInfo = imageInfos[imageInfoIndex].constData();
     }
 
     df->vkUpdateDescriptorSets(dev, uint32_t(writeInfos.count()), writeInfos.constData(), 0, nullptr);
@@ -4210,24 +4216,30 @@ void QRhiVulkan::setShaderResources(QRhiCommandBuffer *cb, QRhiShaderResourceBin
             break;
         case QRhiShaderResourceBinding::SampledTexture:
         {
-            QVkTexture *texD = QRHI_RES(QVkTexture, b->u.stex.tex);
-            QVkSampler *samplerD = QRHI_RES(QVkSampler, b->u.stex.sampler);
-            texD->lastActiveFrameSlot = currentFrameSlot;
-            samplerD->lastActiveFrameSlot = currentFrameSlot;
-            trackedRegisterTexture(&passResTracker, texD,
-                                   QRhiPassResourceTracker::TexSample,
-                                   QRhiPassResourceTracker::toPassTrackerTextureStage(b->stage));
-
-            if (texD->generation != bd.stex.texGeneration
-                    || texD->m_id != bd.stex.texId
-                    || samplerD->generation != bd.stex.samplerGeneration
-                    || samplerD->m_id != bd.stex.samplerId)
-            {
+            const QRhiShaderResourceBinding::Data::SampledTextureData *data = &b->u.stex;
+            if (bd.stex.count != data->count) {
+                bd.stex.count = data->count;
                 rewriteDescSet = true;
-                bd.stex.texId = texD->m_id;
-                bd.stex.texGeneration = texD->generation;
-                bd.stex.samplerId = samplerD->m_id;
-                bd.stex.samplerGeneration = samplerD->generation;
+            }
+            for (int elem = 0; elem < data->count; ++elem) {
+                QVkTexture *texD = QRHI_RES(QVkTexture, data->texSamplers[elem].tex);
+                QVkSampler *samplerD = QRHI_RES(QVkSampler, data->texSamplers[elem].sampler);
+                texD->lastActiveFrameSlot = currentFrameSlot;
+                samplerD->lastActiveFrameSlot = currentFrameSlot;
+                trackedRegisterTexture(&passResTracker, texD,
+                                       QRhiPassResourceTracker::TexSample,
+                                       QRhiPassResourceTracker::toPassTrackerTextureStage(b->stage));
+                if (texD->generation != bd.stex.d[elem].texGeneration
+                        || texD->m_id != bd.stex.d[elem].texId
+                        || samplerD->generation != bd.stex.d[elem].samplerGeneration
+                        || samplerD->m_id != bd.stex.d[elem].samplerId)
+                {
+                    rewriteDescSet = true;
+                    bd.stex.d[elem].texId = texD->m_id;
+                    bd.stex.d[elem].texGeneration = texD->generation;
+                    bd.stex.d[elem].samplerId = samplerD->m_id;
+                    bd.stex.d[elem].samplerGeneration = samplerD->generation;
+                }
             }
         }
             break;
@@ -6065,7 +6077,10 @@ bool QVkShaderResourceBindings::build()
         memset(&vkbinding, 0, sizeof(vkbinding));
         vkbinding.binding = uint32_t(b->binding);
         vkbinding.descriptorType = toVkDescriptorType(b);
-        vkbinding.descriptorCount = 1; // no array support yet
+        if (b->type == QRhiShaderResourceBinding::SampledTexture)
+            vkbinding.descriptorCount = b->u.stex.count;
+        else
+            vkbinding.descriptorCount = 1;
         vkbinding.stageFlags = toVkShaderStageFlags(b->stage);
         vkbindings.append(vkbinding);
     }
diff --git a/src/gui/rhi/qrhivulkan_p_p.h b/src/gui/rhi/qrhivulkan_p_p.h
index fd65417e75..62516e268d 100644
--- a/src/gui/rhi/qrhivulkan_p_p.h
+++ b/src/gui/rhi/qrhivulkan_p_p.h
@@ -254,10 +254,13 @@ struct QVkShaderResourceBindings : public QRhiShaderResourceBindings
         uint generation;
     };
     struct BoundSampledTextureData {
-        quint64 texId;
-        uint texGeneration;
-        quint64 samplerId;
-        uint samplerGeneration;
+        int count;
+        struct {
+            quint64 texId;
+            uint texGeneration;
+            quint64 samplerId;
+            uint samplerGeneration;
+        } d[QRhiShaderResourceBinding::Data::MAX_TEX_SAMPLER_ARRAY_SIZE];
     };
     struct BoundStorageImageData {
         quint64 id;