vk, d3d, gl: Mipmap generation

examples/rhi/shared/texturedcuberenderer.cpp

@@ -55,6 +55,7 @@
 #include "cube.h"
 
 const bool MIPMAP = true;
+const bool AUTOGENMIPMAP = true;
 
 static QBakedShader getShader(const QString &name)
 {
@@ -78,6 +79,8 @@ void TexturedCubeRenderer::initResources(QRhiRenderPassDescriptor *rp)
     QRhiTexture::Flags texFlags = 0;
     if (MIPMAP)
         texFlags |= QRhiTexture::MipMapped;
+    if (AUTOGENMIPMAP)
+        texFlags |= QRhiTexture::UsedWithGenerateMips;
     m_tex = m_r->newTexture(QRhiTexture::RGBA8, QSize(m_image.width(), m_image.height()), 1, texFlags);
     m_tex->build();
 
@@ -189,12 +192,18 @@ void TexturedCubeRenderer::queueResourceUpdates(QRhiResourceUpdateBatch *resourc
         if (MIPMAP) {
             QRhiTextureUploadDescription desc;
             desc.layers.append(QRhiTextureUploadDescription::Layer());
-            // the ghetto mipmap generator...
-            for (int i = 0, ie = m_r->mipLevelsForSize(m_image.size()); i != ie; ++i) {
-                QImage image = m_image.scaled(m_r->sizeForMipLevel(i, m_image.size()));
-                desc.layers[0].mipImages.push_back({ image });
+            if (!AUTOGENMIPMAP) {
+                // the ghetto mipmap generator...
+                for (int i = 0, ie = m_r->mipLevelsForSize(m_image.size()); i != ie; ++i) {
+                    QImage image = m_image.scaled(m_r->sizeForMipLevel(i, m_image.size()));
+                    desc.layers[0].mipImages.push_back({ image });
+                }
+            } else {
+                desc.layers[0].mipImages.push_back({ m_image });
             }
             resourceUpdates->uploadTexture(m_tex, desc);
+            if (AUTOGENMIPMAP)
+                resourceUpdates->generateMips(m_tex);
         } else {
             resourceUpdates->uploadTexture(m_tex, m_image);
         }

examples/rhi/shared/triangleoncuberenderer.cpp

@@ -56,6 +56,8 @@
 const bool IMAGE_UNDER_OFFSCREEN_RENDERING = false;
 const bool UPLOAD_UNDERLAY_ON_EVERY_FRAME = false;
 
+const bool DS_ATT = false; // have a depth-stencil attachment for the offscreen pass
+
 const bool DEPTH_TEXTURE = false; // offscreen pass uses a depth texture (verify with renderdoc etc., ignore valid.layer about ps slot 0)
 const bool MRT = false; // two textures, the second is just cleared as the shader does not write anything (valid.layer may warn but for testing that's ok)
 
@@ -95,6 +97,18 @@ void TriangleOnCubeRenderer::initResources(QRhiRenderPassDescriptor *rp)
         m_tex2->build();
     }
 
+    if (DS_ATT) {
+        m_offscreenTriangle.setDepthWrite(true);
+        m_ds = m_r->newRenderBuffer(QRhiRenderBuffer::DepthStencil, m_tex->pixelSize());
+        m_ds->build();
+    }
+
+    if (DEPTH_TEXTURE) {
+        m_offscreenTriangle.setDepthWrite(true);
+        m_depthTex = m_r->newTexture(QRhiTexture::D32, OFFSCREEN_SIZE, 1, QRhiTexture::RenderTarget);
+        m_depthTex->build();
+    }
+
     m_sampler = m_r->newSampler(QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None, QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge);
     m_sampler->build();
 
@@ -141,12 +155,6 @@ void TriangleOnCubeRenderer::initResources(QRhiRenderPassDescriptor *rp)
 
     m_ps->build();
 
-    if (DEPTH_TEXTURE) {
-        m_offscreenTriangle.setDepthWrite(true);
-        m_depthTex = m_r->newTexture(QRhiTexture::D32, OFFSCREEN_SIZE, 1, QRhiTexture::RenderTarget);
-        m_depthTex->build();
-    }
-
     QRhiTextureRenderTarget::Flags rtFlags = 0;
     if (IMAGE_UNDER_OFFSCREEN_RENDERING)
         rtFlags |= QRhiTextureRenderTarget::PreserveColorContents;
@@ -157,6 +165,8 @@ void TriangleOnCubeRenderer::initResources(QRhiRenderPassDescriptor *rp)
         m_rt = m_r->newTextureRenderTarget(desc, rtFlags);
     } else {
         QRhiTextureRenderTargetDescription desc { m_tex };
+        if (DS_ATT)
+            desc.depthStencilBuffer = m_ds;
         if (MRT) {
             m_offscreenTriangle.setColorAttCount(2);
             desc.colorAttachments.append(m_tex2);
@@ -228,6 +238,11 @@ void TriangleOnCubeRenderer::releaseResources()
         m_tex = nullptr;
     }
 
+    if (m_ds) {
+        m_ds->releaseAndDestroy();
+        m_ds = nullptr;
+    }
+
     if (m_ubuf) {
         m_ubuf->releaseAndDestroy();
         m_ubuf = nullptr;

examples/rhi/shared/triangleoncuberenderer.h

@@ -73,6 +73,7 @@ private:
     bool m_vbufReady = false;
     QRhiBuffer *m_ubuf = nullptr;
     QRhiTexture *m_tex = nullptr;
+    QRhiRenderBuffer *m_ds = nullptr;
     QRhiTexture *m_tex2 = nullptr;
     QRhiTexture *m_depthTex = nullptr;
     QRhiSampler *m_sampler = nullptr;

src/rhi/qrhi.cpp

@@ -469,6 +469,11 @@ void QRhiResourceUpdateBatch::readBackTexture(const QRhiReadbackDescription &rb,
     d->textureReadbacks.append({ rb, result });
 }
 
+void QRhiResourceUpdateBatch::generateMips(QRhiTexture *tex)
+{
+    d->textureMipGens.append({ tex });
+}
+
 void QRhiResourceUpdateBatch::prepareTextureForUse(QRhiTexture *tex, TexturePrepareFlags flags)
 {
     d->texturePrepares.append({ tex, flags });
@@ -513,6 +518,7 @@ void QRhiResourceUpdateBatchPrivate::free()
     textureCopies.clear();
     textureResolves.clear();
     textureReadbacks.clear();
+    textureMipGens.clear();
     texturePrepares.clear();
 
     rhi->resUpdPoolMap.clearBit(poolIndex);
@@ -527,6 +533,7 @@ void QRhiResourceUpdateBatchPrivate::merge(QRhiResourceUpdateBatchPrivate *other
     textureCopies += other->textureCopies;
     textureResolves += other->textureResolves;
     textureReadbacks += other->textureReadbacks;
+    textureMipGens += other->textureMipGens;
     texturePrepares += other->texturePrepares;
 }
 

src/rhi/qrhi.h

@@ -415,7 +415,8 @@ public:
         CubeMap = 1 << 2,
         MipMapped = 1 << 3,
         sRGB = 1 << 4,
-        UsedAsTransferSource = 1 << 5 // will (also) be used as the source of a readback or copy or resolve
+        UsedAsTransferSource = 1 << 5, // will (also) be used as the source of a readback or copy or resolve
+        UsedWithGenerateMips = 1 << 6
     };
     Q_DECLARE_FLAGS(Flags, Flag)
 
@@ -918,7 +919,7 @@ public:
 
     // Sometimes committing the updates is necessary without starting a render
     // pass. Not often needed, updates should typically be passed to beginPass
-    // (or endPass, in case of readbacks) instead.
+    // (or endPass, in case of readbacks or resolves) instead.
     void resourceUpdate(QRhiResourceUpdateBatch *resourceUpdates);
 
     void beginPass(QRhiRenderTarget *rt,
@@ -1030,6 +1031,7 @@ public:
     void copyTexture(QRhiTexture *dst, QRhiTexture *src, const QRhiTextureCopyDescription &desc = QRhiTextureCopyDescription());
     void resolveTexture(QRhiTexture *dst, const QRhiTextureResolveDescription &desc);
     void readBackTexture(const QRhiReadbackDescription &rb, QRhiReadbackResult *result);
+    void generateMips(QRhiTexture *tex);
 
     // This is not normally needed, textures that have an upload or are used
     // with a TextureRenderTarget will be fine without it. May be more relevant later.

src/rhi/qrhi_p.h

@@ -204,6 +204,10 @@ struct QRhiResourceUpdateBatchPrivate
         QRhiReadbackResult *result;
     };
 
+    struct TextureMipGen {
+        QRhiTexture *tex = nullptr;
+    };
+
     struct TexturePrepare {
         TexturePrepare() { }
         TexturePrepare(QRhiTexture *tex_, QRhiResourceUpdateBatch::TexturePrepareFlags flags_)
@@ -220,6 +224,7 @@ struct QRhiResourceUpdateBatchPrivate
     QVector<TextureCopy> textureCopies;
     QVector<TextureResolve> textureResolves;
     QVector<TextureRead> textureReadbacks;
+    QVector<TextureMipGen> textureMipGens;
     QVector<TexturePrepare> texturePrepares;
 
     QRhiResourceUpdateBatch *q = nullptr;
@@ -238,6 +243,7 @@ Q_DECLARE_TYPEINFO(QRhiResourceUpdateBatchPrivate::TextureUpload, Q_MOVABLE_TYPE
 Q_DECLARE_TYPEINFO(QRhiResourceUpdateBatchPrivate::TextureCopy, Q_MOVABLE_TYPE);
 Q_DECLARE_TYPEINFO(QRhiResourceUpdateBatchPrivate::TextureResolve, Q_MOVABLE_TYPE);
 Q_DECLARE_TYPEINFO(QRhiResourceUpdateBatchPrivate::TextureRead, Q_MOVABLE_TYPE);
+Q_DECLARE_TYPEINFO(QRhiResourceUpdateBatchPrivate::TextureMipGen, Q_MOVABLE_TYPE);
 Q_DECLARE_TYPEINFO(QRhiResourceUpdateBatchPrivate::TexturePrepare, Q_MOVABLE_TYPE);
 
 template<typename T>

src/rhi/qrhid3d11.cpp

@@ -955,6 +955,14 @@ void QRhiD3D11::enqueueResourceUpdates(QRhiCommandBuffer *cb, QRhiResourceUpdate
         activeReadbacks.append(aRb);
     }
 
+    for (const QRhiResourceUpdateBatchPrivate::TextureMipGen &u : ud->textureMipGens) {
+        Q_ASSERT(u.tex->flags().testFlag(QRhiTexture::UsedWithGenerateMips));
+        QD3D11CommandBuffer::Command cmd;
+        cmd.cmd = QD3D11CommandBuffer::Command::GenMip;
+        cmd.args.genMip.tex = QRHI_RES(QD3D11Texture, u.tex);
+        cbD->commands.append(cmd);
+    }
+
     ud->free();
 }
 
@@ -1351,6 +1359,9 @@ void QRhiD3D11::executeCommandBuffer(QD3D11CommandBuffer *cbD)
                                         cmd.args.resolveSubRes.src, cmd.args.resolveSubRes.srcSubRes,
                                         cmd.args.resolveSubRes.format);
             break;
+        case QD3D11CommandBuffer::Command::GenMip:
+            context->GenerateMips(cmd.args.genMip.tex->srv);
+            break;
         default:
             break;
         }
@@ -1574,14 +1585,27 @@ bool QD3D11Texture::build()
             return false;
         }
     }
+    if (isDepth && hasMipMaps) {
+        qWarning("Depth texture cannot have mipmaps");
+        return false;
+    }
 
     uint bindFlags = D3D11_BIND_SHADER_RESOURCE;
+    uint miscFlags = isCube ? D3D11_RESOURCE_MISC_TEXTURECUBE : 0;
     if (m_flags.testFlag(RenderTarget)) {
         if (isDepth)
             bindFlags |= D3D11_BIND_DEPTH_STENCIL;
         else
             bindFlags |= D3D11_BIND_RENDER_TARGET;
     }
+    if (m_flags.testFlag(UsedWithGenerateMips)) {
+        if (isDepth) {
+            qWarning("Depth texture cannot have mipmaps generated");
+            return false;
+        }
+        bindFlags |= D3D11_BIND_RENDER_TARGET;
+        miscFlags |= D3D11_RESOURCE_MISC_GENERATE_MIPS;
+    }
 
     D3D11_TEXTURE2D_DESC desc;
     memset(&desc, 0, sizeof(desc));
@@ -1593,7 +1617,7 @@ bool QD3D11Texture::build()
     desc.SampleDesc = sampleDesc;
     desc.Usage = D3D11_USAGE_DEFAULT;
     desc.BindFlags = bindFlags;
-    desc.MiscFlags = isCube ? D3D11_RESOURCE_MISC_TEXTURECUBE : 0;
+    desc.MiscFlags = miscFlags;
 
     HRESULT hr = rhiD->dev->CreateTexture2D(&desc, nullptr, &tex);
     if (FAILED(hr)) {

src/rhi/qrhid3d11_p.h

@@ -248,7 +248,8 @@ struct QD3D11CommandBuffer : public QRhiCommandBuffer
             DrawIndexed,
             UpdateSubRes,
             CopySubRes,
-            ResolveSubRes
+            ResolveSubRes,
+            GenMip
         };
         enum ClearFlag { Color = 1, Depth = 2, Stencil = 4 };
         Cmd cmd;
@@ -335,6 +336,9 @@ struct QD3D11CommandBuffer : public QRhiCommandBuffer
                 UINT srcSubRes;
                 DXGI_FORMAT format;
             } resolveSubRes;
+            struct {
+                QD3D11Texture *tex;
+            } genMip;
         } args;
     };
 

src/rhi/qrhigles2.cpp

@@ -736,6 +736,13 @@ void QRhiGles2::enqueueResourceUpdates(QRhiCommandBuffer *cb, QRhiResourceUpdate
         cbD->commands.append(cmd);
     }
 
+    for (const QRhiResourceUpdateBatchPrivate::TextureMipGen &u : ud->textureMipGens) {
+        QGles2CommandBuffer::Command cmd;
+        cmd.cmd = QGles2CommandBuffer::Command::GenMip;
+        cmd.args.genMip.tex = QRHI_RES(QGles2Texture, u.tex);
+        cbD->commands.append(cmd);
+    }
+
     ud->free();
 }
 
@@ -1192,6 +1199,10 @@ void QRhiGles2::executeCommandBuffer(QRhiCommandBuffer *cb)
             f->glBindFramebuffer(GL_FRAMEBUFFER, ctx->defaultFramebufferObject());
         }
             break;
+        case QGles2CommandBuffer::Command::GenMip:
+            f->glBindTexture(cmd.args.genMip.tex->target, cmd.args.genMip.tex->texture);
+            f->glGenerateMipmap(cmd.args.genMip.tex->target);
+            break;
         default:
             break;
         }

src/rhi/qrhigles2_p.h

@@ -242,7 +242,8 @@ struct QGles2CommandBuffer : public QRhiCommandBuffer
             SubImage,
             CompressedImage,
             CompressedSubImage,
-            BlitFromRenderbuffer
+            BlitFromRenderbuffer,
+            GenMip
         };
         Cmd cmd;
         union {
@@ -361,6 +362,9 @@ struct QGles2CommandBuffer : public QRhiCommandBuffer
                 int dstLayer;
                 int dstLevel;
             } blitFromRb;
+            struct {
+                QGles2Texture *tex;
+            } genMip;
         } args;
     };
 

src/rhi/qrhivulkan.cpp

@@ -1768,6 +1768,35 @@ void QRhiVulkan::bufferBarrier(QRhiCommandBuffer *cb, QRhiBuffer *buf)
                              0, 0, nullptr, 1, &bufMemBarrier, 0, nullptr);
 }
 
+void QRhiVulkan::imageSubResBarrier(QRhiCommandBuffer *cb, QRhiTexture *tex,
+                                    VkImageLayout oldLayout, VkImageLayout newLayout,
+                                    VkAccessFlags srcAccess, VkAccessFlags dstAccess,
+                                    VkPipelineStageFlags srcStage, VkPipelineStageFlags dstStage,
+                                    int layer, int level)
+{
+    QVkTexture *texD = QRHI_RES(QVkTexture, tex);
+
+    VkImageMemoryBarrier barrier;
+    memset(&barrier, 0, sizeof(barrier));
+    barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+    barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+    barrier.subresourceRange.baseMipLevel = level;
+    barrier.subresourceRange.levelCount = 1;
+    barrier.subresourceRange.baseArrayLayer = layer;
+    barrier.subresourceRange.layerCount = 1;
+    barrier.oldLayout = oldLayout;
+    barrier.newLayout = newLayout;
+    barrier.srcAccessMask = srcAccess;
+    barrier.dstAccessMask = dstAccess;
+    barrier.image = texD->image;
+
+    df->vkCmdPipelineBarrier(QRHI_RES(QVkCommandBuffer, cb)->cb,
+                             srcStage,
+                             dstStage,
+                             0, 0, nullptr, 0, nullptr,
+                             1, &barrier);
+}
+
 void QRhiVulkan::imageBarrier(QRhiCommandBuffer *cb, QRhiTexture *tex,
                               VkImageLayout newLayout,
                               VkAccessFlags srcAccess, VkAccessFlags dstAccess,
@@ -1817,7 +1846,8 @@ void QRhiVulkan::prepareForTransferDest(QRhiCommandBuffer *cb, QVkTexture *texD)
 void QRhiVulkan::prepareForTransferSrc(QRhiCommandBuffer *cb, QVkTexture *texD)
 {
     if (texD->layout != VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL) {
-        Q_ASSERT(texD->m_flags.testFlag(QRhiTexture::UsedAsTransferSource));
+        Q_ASSERT(texD->m_flags.testFlag(QRhiTexture::UsedAsTransferSource)
+                 || texD->m_flags.testFlag(QRhiTexture::UsedWithGenerateMips));
         // assume the texture was written (so block up to color output, not just fragment)
         imageBarrier(cb, texD,
                      VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
@@ -2268,6 +2298,71 @@ void QRhiVulkan::enqueueResourceUpdates(QRhiCommandBuffer *cb, QRhiResourceUpdat
         activeReadbacks.append(aRb);
     }
 
+    for (const QRhiResourceUpdateBatchPrivate::TextureMipGen &u : ud->textureMipGens) {
+        QVkTexture *utexD = QRHI_RES(QVkTexture, u.tex);
+        Q_ASSERT(utexD->m_flags.testFlag(QRhiTexture::UsedWithGenerateMips));
+        int w = utexD->m_pixelSize.width();
+        int h = utexD->m_pixelSize.height();
+
+        prepareForTransferSrc(cb, utexD);
+
+        for (int level = 1; level < utexD->mipLevelCount; ++level) {
+            if (level > 1) {
+                imageSubResBarrier(cb, utexD,
+                                   VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
+                                   VK_ACCESS_TRANSFER_WRITE_BIT, VK_ACCESS_TRANSFER_READ_BIT,
+                                   VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT,
+                                   0, level - 1);
+            }
+
+            imageSubResBarrier(cb, utexD,
+                               VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
+                               VK_ACCESS_TRANSFER_READ_BIT, VK_ACCESS_TRANSFER_WRITE_BIT,
+                               VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT,
+                               0, level);
+
+            VkImageBlit region;
+            memset(&region, 0, sizeof(region));
+
+            region.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+            region.srcSubresource.mipLevel = level - 1;
+            region.srcSubresource.baseArrayLayer = 0;
+            region.srcSubresource.layerCount = 1;
+
+            region.srcOffsets[1].x = w;
+            region.srcOffsets[1].y = h;
+            region.srcOffsets[1].z = 1;
+
+            region.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+            region.dstSubresource.mipLevel = level;
+            region.dstSubresource.baseArrayLayer = 0;
+            region.dstSubresource.layerCount = 1;
+
+            region.dstOffsets[1].x = w >> 1;
+            region.dstOffsets[1].y = h >> 1;
+            region.dstOffsets[1].z = 1;
+
+            df->vkCmdBlitImage(cbD->cb,
+                               utexD->image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
+                               utexD->image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
+                               1, &region,
+                               VK_FILTER_LINEAR);
+
+            w >>= 1;
+            h >>= 1;
+
+            if (level == utexD->mipLevelCount - 1) {
+                imageSubResBarrier(cb, utexD,
+                                   VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
+                                   VK_ACCESS_TRANSFER_WRITE_BIT, VK_ACCESS_TRANSFER_READ_BIT,
+                                   VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT,
+                                   0, level);
+            }
+        }
+
+        finishTransferDest(cb, utexD);
+    }
+
     for (const QRhiResourceUpdateBatchPrivate::TexturePrepare &u : ud->texturePrepares) {
         if (u.flags.testFlag(QRhiResourceUpdateBatch::TextureRead)) {
             QVkTexture *utexD = QRHI_RES(QVkTexture, u.tex);
@@ -3339,6 +3434,8 @@ bool QVkTexture::build()
     }
     if (m_flags.testFlag(QRhiTexture::UsedAsTransferSource))
         imageInfo.usage |= VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
+    if (m_flags.testFlag(QRhiTexture::UsedWithGenerateMips))
+        imageInfo.usage |= VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
 
     VmaAllocationCreateInfo allocInfo;
     memset(&allocInfo, 0, sizeof(allocInfo));

src/rhi/qrhivulkan_p.h

@@ -426,6 +426,11 @@ public:
     void finishActiveReadbacks(bool forced = false);
 
     void bufferBarrier(QRhiCommandBuffer *cb, QRhiBuffer *buf);
+    void imageSubResBarrier(QRhiCommandBuffer *cb, QRhiTexture *tex,
+                            VkImageLayout oldLayout, VkImageLayout newLayout,
+                            VkAccessFlags srcAccess, VkAccessFlags dstAccess,
+                            VkPipelineStageFlags srcStage, VkPipelineStageFlags dstStage,
+                            int layer, int level);
     void imageBarrier(QRhiCommandBuffer *cb, QRhiTexture *tex,
                       VkImageLayout newLayout,
                       VkAccessFlags srcAccess, VkAccessFlags dstAccess,

todo.txt

@@ -11,6 +11,7 @@ mtl: msaa tex+rt
 mtl: resolveimage (color)
 mtl: buffer upload with offset/size
 mtl: color renderbuffer
+mtl: mipmap generation
 
 gl: tex formats (texture, readback)
 gl: srgb
@@ -19,8 +20,6 @@ test cubemap
 test cubemap face as target
 test cubemap face readback
 
-mipmap generation?
-
 advanced blend modes
 
 resource import/export, what's the interop story
@@ -67,6 +66,7 @@ dxc for d3d as an alternative to fxc?
 hlsl -> dxc -> spirv -> spirv-cross hmmm...
 
 +++ done
+vk, d3d, gl: mipmap gen
 msaa swapchain readback
 d3d: resolveimage (color)
 vk: resolveimage (color)