Implement setMinMaxLevels for Metal

filament/backend/CMakeLists.txt

@@ -412,6 +412,7 @@ if (APPLE)
         test/test_RenderExternalImage.cpp
         test/test_StencilBuffer.cpp
         test/test_Scissor.cpp
+        test/test_MipLevels.cpp
         )
 
     target_link_libraries(backend_test PRIVATE

filament/backend/src/metal/MetalDriver.mm

@@ -345,7 +345,7 @@
         auto colorTexture = handle_cast<MetalTexture>(buffer.handle);
         ASSERT_PRECONDITION(colorTexture->getMtlTextureForWrite(),
                 "Color texture passed to render target has no texture allocation");
-        colorTexture->updateLodRange(buffer.level);
+        colorTexture->extendLodRangeTo(buffer.level);
         colorAttachments[i] = { colorTexture, color[i].level, color[i].layer };
     }
 
@@ -356,7 +356,7 @@
         auto depthTexture = handle_cast<MetalTexture>(depth.handle);
         ASSERT_PRECONDITION(depthTexture->getMtlTextureForWrite(),
                 "Depth texture passed to render target has no texture allocation.");
-        depthTexture->updateLodRange(depth.level);
+        depthTexture->extendLodRangeTo(depth.level);
         depthAttachment = { depthTexture, depth.level, depth.layer };
     }
 
@@ -367,7 +367,7 @@
         auto stencilTexture = handle_cast<MetalTexture>(stencil.handle);
         ASSERT_PRECONDITION(stencilTexture->getMtlTextureForWrite(),
                 "Stencil texture passed to render target has no texture allocation.");
-        stencilTexture->updateLodRange(stencil.level);
+        stencilTexture->extendLodRangeTo(stencil.level);
         stencilAttachment = { stencilTexture, stencil.level, stencil.layer };
     }
 
@@ -789,6 +789,8 @@
 }
 
 void MetalDriver::setMinMaxLevels(Handle<HwTexture> th, uint32_t minLevel, uint32_t maxLevel) {
+    auto tex = handle_cast<MetalTexture>(th);
+    tex->setLodRange(minLevel, maxLevel);
 }
 
 void MetalDriver::update3DImage(Handle<HwTexture> th, uint32_t level,
@@ -900,14 +902,13 @@
     // 2. LOD-clamped textures
     //
     // Both of these cases prevent us from knowing the final id<MTLTexture> that will be bound into
-    // the argument buffer representing the sampler group. So, we bind what we can now and wait
-    // until draw call time to bind any special cases (done in finalizeSamplerGroup).
+    // the argument buffer representing the sampler group. So, we wait until draw call time to bind
+    // textures (done in finalizeSamplerGroup).
     // The good news is that once a render pass has started, the texture bindings won't change.
     // A SamplerGroup is "finalized" when all of its textures have been set and is ready for use in
     // a draw call.
-    // Even if we do know all the final textures at this point, we still wait until draw call time
-    // to call finalizeSamplerGroup, which has one additional responsibility: to call useResources
-    // for all the textures, which is required by Metal.
+    // finalizeSamplerGroup has one additional responsibility: to call useResources for all the
+    // textures, which is required by Metal.
     for (size_t s = 0; s < data.size / sizeof(SamplerDescriptor); s++) {
         if (!samplers[s].t) {
             // Assign a default texture / sampler to empty slots.
@@ -930,27 +931,6 @@
         sb->setFinalizedSampler(s, sampler);
 
         sb->setTextureHandle(s, samplers[s].t);
-
-        auto* t = handle_cast<MetalTexture>(samplers[s].t);
-        assert_invariant(t);
-
-        // If this texture is an external texture, we defer binding the texture until draw call time
-        // (in finalizeSamplerGroup).
-        if (t->target == SamplerType::SAMPLER_EXTERNAL) {
-            continue;
-        }
-
-        if (!t->allLodsValid()) {
-            // The texture doesn't have all of its LODs loaded, and this could change by the time we
-            // issue a draw call with this sampler group. So, we defer binding the texture until
-            // draw call time (in finalizeSamplerGroup).
-            continue;
-        }
-
-        // If we get here, we know we have a valid MTLTexture that's guaranteed not to change.
-        id<MTLTexture> mtlTexture = t->getMtlTextureForRead();
-        assert_invariant(mtlTexture);
-        sb->setFinalizedTexture(s, mtlTexture);
     }
 
     scheduleDestroy(std::move(data));
@@ -1376,8 +1356,8 @@
 }
 
 void MetalDriver::finalizeSamplerGroup(MetalSamplerGroup* samplerGroup) {
-    // All of the id<MTLSamplerState> objects have already been bound to the argument buffer.
-    // Here we bind any textures that were unable to be bound in updateSamplerGroup.
+    // All the id<MTLSamplerState> objects have already been bound to the argument buffer.
+    // Here we bind all the textures.
 
     id<MTLCommandBuffer> cmdBuffer = getPendingCommandBuffer(mContext);
 

filament/backend/src/metal/MetalHandles.h

@@ -217,21 +217,14 @@ class MetalTexture : public HwTexture {
     void generateMipmaps() noexcept;
 
     // A texture starts out with none of its mip levels (also referred to as LODs) available for
-    // reading. 3 actions update the range of LODs available:
+    // reading. 4 actions update the range of LODs available:
     // - calling loadImage
     // - calling generateMipmaps
     // - using the texture as a render target attachment
-    // The range of available mips can only increase, never decrease.
+    // - calling setMinMaxLevels
     // A texture's available mips are consistent throughout a render pass.
-    void updateLodRange(uint32_t level);
-    void updateLodRange(uint32_t minLevel, uint32_t maxLevel);
-
-    // Returns true if the texture has all of its mip levels accessible for reading.
-    // For any MetalTexture, once this is true, will always return true.
-    // The value returned will remain consistent for an entire render pass.
-    bool allLodsValid() const {
-        return minLod == 0 && maxLod == levels - 1;
-    }
+    void setLodRange(uint32_t minLevel, uint32_t maxLevel);
+    void extendLodRangeTo(uint32_t level);
 
     static MTLPixelFormat decidePixelFormat(MetalContext* context, TextureFormat format);
 

filament/backend/src/metal/MetalHandles.mm

@@ -513,7 +513,7 @@ void presentDrawable(bool presentFrame, void* user) {
     : HwTexture(target, levels, samples, width, height, depth, format, usage), context(context),
         externalImage(context) {
     texture = metalTexture;
-    updateLodRange(0, levels - 1);
+    setLodRange(0, levels - 1);
 }
 
 MetalTexture::~MetalTexture() {
@@ -658,14 +658,14 @@ void presentDrawable(bool presentFrame, void* user) {
         }
     }
 
-    updateLodRange(level);
+    extendLodRangeTo(level);
 }
 
 void MetalTexture::generateMipmaps() noexcept {
     id <MTLBlitCommandEncoder> blitEncoder = [getPendingCommandBuffer(&context) blitCommandEncoder];
     [blitEncoder generateMipmapsForTexture:texture];
     [blitEncoder endEncoding];
-    updateLodRange(0, texture.mipmapLevelCount - 1);
+    setLodRange(0, texture.mipmapLevelCount - 1);
 }
 
 void MetalTexture::loadSlice(uint32_t level, MTLRegion region, uint32_t byteOffset, uint32_t slice,
@@ -788,18 +788,18 @@ void presentDrawable(bool presentFrame, void* user) {
     context.blitter->blit(getPendingCommandBuffer(&context), args, "Texture upload blit");
 }
 
-void MetalTexture::updateLodRange(uint32_t level) {
+void MetalTexture::extendLodRangeTo(uint32_t level) {
     assert_invariant(!isInRenderPass(&context));
     minLod = std::min(minLod, level);
     maxLod = std::max(maxLod, level);
     lodTextureView = nil;
 }
 
-void MetalTexture::updateLodRange(uint32_t min, uint32_t max) {
+void MetalTexture::setLodRange(uint32_t min, uint32_t max) {
     assert_invariant(!isInRenderPass(&context));
     assert_invariant(min <= max);
-    minLod = std::min(minLod, min);
-    maxLod = std::max(maxLod, max);
+    minLod = min;
+    maxLod = max;
     lodTextureView = nil;
 }
 

filament/backend/test/BackendTest.cpp

@@ -211,66 +211,5 @@ int runTests() {
     return RUN_ALL_TESTS();
 }
 
-void getPixelInfo(PixelDataFormat format, PixelDataType type, size_t& outComponents, int& outBpp) {
-    assert_invariant(type != PixelDataType::COMPRESSED);
-    switch (format) {
-        case PixelDataFormat::UNUSED:
-        case PixelDataFormat::R:
-        case PixelDataFormat::R_INTEGER:
-        case PixelDataFormat::DEPTH_COMPONENT:
-        case PixelDataFormat::ALPHA:
-            outComponents = 1;
-            break;
-        case PixelDataFormat::RG:
-        case PixelDataFormat::RG_INTEGER:
-        case PixelDataFormat::DEPTH_STENCIL:
-            outComponents = 2;
-            break;
-        case PixelDataFormat::RGB:
-        case PixelDataFormat::RGB_INTEGER:
-            outComponents = 3;
-            break;
-        case PixelDataFormat::RGBA:
-        case PixelDataFormat::RGBA_INTEGER:
-            outComponents = 4;
-            break;
-    }
-
-    outBpp = outComponents;
-    switch (type) {
-        case PixelDataType::COMPRESSED: // Impossible -- to squash the IDE warnings
-        case PixelDataType::UBYTE:
-        case PixelDataType::BYTE:
-            // nothing to do
-            break;
-        case PixelDataType::USHORT:
-        case PixelDataType::SHORT:
-        case PixelDataType::HALF:
-            outBpp *= 2;
-            break;
-        case PixelDataType::UINT:
-        case PixelDataType::INT:
-        case PixelDataType::FLOAT:
-            outBpp *= 4;
-            break;
-        case PixelDataType::UINT_10F_11F_11F_REV:
-            // Special case, format must be RGB and uses 4 bytes
-            assert_invariant(format == PixelDataFormat::RGB);
-            outBpp = 4;
-            break;
-        case PixelDataType::UINT_2_10_10_10_REV:
-            // Special case, format must be RGBA and uses 4 bytes
-            assert_invariant(format == PixelDataFormat::RGBA);
-            outBpp = 4;
-            break;
-        case PixelDataType::USHORT_565:
-            // Special case, format must be RGB and uses 2 bytes
-            assert_invariant(format == PixelDataFormat::RGB);
-            outBpp = 2;
-            break;
-    }
-}
-
-
 } // namespace test
 

filament/backend/test/BackendTest.h

@@ -75,12 +75,6 @@ class BackendTest : public ::testing::Test {
     filament::backend::Handle<filament::backend::HwBufferObject> uniform;
 };
 
-
-// Utilities
-
-void getPixelInfo(filament::backend::PixelDataFormat format, filament::backend::PixelDataType type,
-        size_t& outComponents, int& outBpp);
-
 } // namespace test
 
 #endif