1 files changed, 513 insertions, 0 deletions
diff --git a/examples/vulkan/shared/trianglerenderer.cpp b/examples/vulkan/shared/trianglerenderer.cpp
new file mode 100644
index 0000000000..f2e636bbe6
--- /dev/null
+++ b/examples/vulkan/shared/trianglerenderer.cpp
@@ -0,0 +1,513 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "trianglerenderer.h"
+#include <QVulkanFunctions>
+#include <QFile>
+
+// Note that the vertex data and the projection matrix assume OpenGL. With
+// Vulkan Y is negated in clip space and the near/far plane is at 0/1 instead
+// of -1/1. These will be corrected for by an extra transformation when
+// calculating the modelview-projection matrix.
+static float vertexData[] = {
+     0.0f,   0.5f,   1.0f, 0.0f, 0.0f,
+    -0.5f,  -0.5f,   0.0f, 1.0f, 0.0f,
+     0.5f,  -0.5f,   0.0f, 0.0f, 1.0f
+};
+
+static const int UNIFORM_DATA_SIZE = 16 * sizeof(float);
+
+static inline VkDeviceSize aligned(VkDeviceSize v, VkDeviceSize byteAlign)
+{
+    return (v + byteAlign - 1) & ~(byteAlign - 1);
+}
+
+TriangleRenderer::TriangleRenderer(QVulkanWindow *w, bool msaa)
+    : m_window(w)
+{
+    if (msaa) {
+        QSet<int> counts = w->supportedSampleCounts();
+        qDebug() << "Supported sample counts:" << counts;
+        for (int s = 16; s >= 4; s /= 2) {
+            if (counts.contains(s)) {
+                qDebug("Requesting sample count %d", s);
+                m_window->setSampleCount(s);
+                break;
+            }
+        }
+    }
+}
+
+VkShaderModule TriangleRenderer::createShader(const QString &name)
+{
+    QFile file(name);
+    if (!file.open(QIODevice::ReadOnly)) {
+        qWarning("Failed to read shader %s", qPrintable(name));
+        return VK_NULL_HANDLE;
+    }
+    QByteArray blob = file.readAll();
+    file.close();
+
+    VkShaderModuleCreateInfo shaderInfo;
+    memset(&shaderInfo, 0, sizeof(shaderInfo));
+    shaderInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
+    shaderInfo.codeSize = blob.size();
+    shaderInfo.pCode = reinterpret_cast<const uint32_t *>(blob.constData());
+    VkShaderModule shaderModule;
+    VkResult err = m_devFuncs->vkCreateShaderModule(m_window->device(), &shaderInfo, nullptr, &shaderModule);
+    if (err != VK_SUCCESS) {
+        qWarning("Failed to create shader module: %d", err);
+        return VK_NULL_HANDLE;
+    }
+
+    return shaderModule;
+}
+
+void TriangleRenderer::initResources()
+{
+    qDebug("initResources");
+
+    VkDevice dev = m_window->device();
+    m_devFuncs = m_window->vulkanInstance()->deviceFunctions(dev);
+
+    // Prepare the vertex and uniform data. The vertex data will never
+    // change so one buffer is sufficient regardless of the value of
+    // QVulkanWindow::CONCURRENT_FRAME_COUNT. Uniform data is changing per
+    // frame however so active frames have to have a dedicated copy.
+
+    // Use just one memory allocation and one buffer. We will then specify the
+    // appropriate offsets for uniform buffers in the VkDescriptorBufferInfo.
+    // Have to watch out for
+    // VkPhysicalDeviceLimits::minUniformBufferOffsetAlignment, though.
+
+    // The uniform buffer is not strictly required in this example, we could
+    // have used push constants as well since our single matrix (64 bytes) fits
+    // into the spec mandated minimum limit of 128 bytes. However, once that
+    // limit is not sufficient, the per-frame buffers, as shown below, will
+    // become necessary.
+
+    const int concurrentFrameCount = m_window->concurrentFrameCount();
+    const VkPhysicalDeviceLimits *pdevLimits = &m_window->physicalDeviceProperties()->limits;
+    const VkDeviceSize uniAlign = pdevLimits->minUniformBufferOffsetAlignment;
+    qDebug("uniform buffer offset alignment is %u", (uint) uniAlign);
+    VkBufferCreateInfo bufInfo;
+    memset(&bufInfo, 0, sizeof(bufInfo));
+    bufInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
+    // Our internal layout is vertex, uniform, uniform, ... with each uniform buffer start offset aligned to uniAlign.
+    const VkDeviceSize vertexAllocSize = aligned(sizeof(vertexData), uniAlign);
+    const VkDeviceSize uniformAllocSize = aligned(UNIFORM_DATA_SIZE, uniAlign);
+    bufInfo.size = vertexAllocSize + concurrentFrameCount * uniformAllocSize;
+    bufInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT;
+
+    VkResult err = m_devFuncs->vkCreateBuffer(dev, &bufInfo, nullptr, &m_buf);
+    if (err != VK_SUCCESS)
+        qFatal("Failed to create buffer: %d", err);
+
+    VkMemoryRequirements memReq;
+    m_devFuncs->vkGetBufferMemoryRequirements(dev, m_buf, &memReq);
+
+    VkMemoryAllocateInfo memAllocInfo = {
+        VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
+        nullptr,
+        memReq.size,
+        m_window->hostVisibleMemoryIndex()
+    };
+
+    err = m_devFuncs->vkAllocateMemory(dev, &memAllocInfo, nullptr, &m_bufMem);
+    if (err != VK_SUCCESS)
+        qFatal("Failed to allocate memory: %d", err);
+
+    err = m_devFuncs->vkBindBufferMemory(dev, m_buf, m_bufMem, 0);
+    if (err != VK_SUCCESS)
+        qFatal("Failed to bind buffer memory: %d", err);
+
+    quint8 *p;
+    err = m_devFuncs->vkMapMemory(dev, m_bufMem, 0, memReq.size, 0, reinterpret_cast<void **>(&p));
+    if (err != VK_SUCCESS)
+        qFatal("Failed to map memory: %d", err);
+    memcpy(p, vertexData, sizeof(vertexData));
+    QMatrix4x4 ident;
+    memset(m_uniformBufInfo, 0, sizeof(m_uniformBufInfo));
+    for (int i = 0; i < concurrentFrameCount; ++i) {
+        const VkDeviceSize offset = vertexAllocSize + i * uniformAllocSize;
+        memcpy(p + offset, ident.constData(), 16 * sizeof(float));
+        m_uniformBufInfo[i].buffer = m_buf;
+        m_uniformBufInfo[i].offset = offset;
+        m_uniformBufInfo[i].range = uniformAllocSize;
+    }
+    m_devFuncs->vkUnmapMemory(dev, m_bufMem);
+
+    VkVertexInputBindingDescription vertexBindingDesc = {
+        0, // binding
+        5 * sizeof(float),
+        VK_VERTEX_INPUT_RATE_VERTEX
+    };
+    VkVertexInputAttributeDescription vertexAttrDesc[] = {
+        { // position
+            0, // location
+            0, // binding
+            VK_FORMAT_R32G32_SFLOAT,
+            0
+        },
+        { // color
+            1,
+            0,
+            VK_FORMAT_R32G32B32_SFLOAT,
+            2 * sizeof(float)
+        }
+    };
+
+    VkPipelineVertexInputStateCreateInfo vertexInputInfo;
+    vertexInputInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
+    vertexInputInfo.pNext = nullptr;
+    vertexInputInfo.flags = 0;
+    vertexInputInfo.vertexBindingDescriptionCount = 1;
+    vertexInputInfo.pVertexBindingDescriptions = &vertexBindingDesc;
+    vertexInputInfo.vertexAttributeDescriptionCount = 2;
+    vertexInputInfo.pVertexAttributeDescriptions = vertexAttrDesc;
+
+    // Set up descriptor set and its layout.
+    VkDescriptorPoolSize descPoolSizes = { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, uint32_t(concurrentFrameCount) };
+    VkDescriptorPoolCreateInfo descPoolInfo;
+    memset(&descPoolInfo, 0, sizeof(descPoolInfo));
+    descPoolInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
+    descPoolInfo.maxSets = concurrentFrameCount;
+    descPoolInfo.poolSizeCount = 1;
+    descPoolInfo.pPoolSizes = &descPoolSizes;
+    err = m_devFuncs->vkCreateDescriptorPool(dev, &descPoolInfo, nullptr, &m_descPool);
+    if (err != VK_SUCCESS)
+        qFatal("Failed to create descriptor pool: %d", err);
+
+    VkDescriptorSetLayoutBinding layoutBinding = {
+        0, // binding
+        VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
+        1,
+        VK_SHADER_STAGE_VERTEX_BIT,
+        nullptr
+    };
+    VkDescriptorSetLayoutCreateInfo descLayoutInfo = {
+        VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO,
+        nullptr,
+        0,
+        1,
+        &layoutBinding
+    };
+    err = m_devFuncs->vkCreateDescriptorSetLayout(dev, &descLayoutInfo, nullptr, &m_descSetLayout);
+    if (err != VK_SUCCESS)
+        qFatal("Failed to create descriptor set layout: %d", err);
+
+    for (int i = 0; i < concurrentFrameCount; ++i) {
+        VkDescriptorSetAllocateInfo descSetAllocInfo = {
+            VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO,
+            nullptr,
+            m_descPool,
+            1,
+            &m_descSetLayout
+        };
+        err = m_devFuncs->vkAllocateDescriptorSets(dev, &descSetAllocInfo, &m_descSet[i]);
+        if (err != VK_SUCCESS)
+            qFatal("Failed to allocate descriptor set: %d", err);
+
+        VkWriteDescriptorSet descWrite;
+        memset(&descWrite, 0, sizeof(descWrite));
+        descWrite.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
+        descWrite.dstSet = m_descSet[i];
+        descWrite.descriptorCount = 1;
+        descWrite.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
+        descWrite.pBufferInfo = &m_uniformBufInfo[i];
+        m_devFuncs->vkUpdateDescriptorSets(dev, 1, &descWrite, 0, nullptr);
+    }
+
+    // Pipeline cache
+    VkPipelineCacheCreateInfo pipelineCacheInfo;
+    memset(&pipelineCacheInfo, 0, sizeof(pipelineCacheInfo));
+    pipelineCacheInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_CACHE_CREATE_INFO;
+    err = m_devFuncs->vkCreatePipelineCache(dev, &pipelineCacheInfo, nullptr, &m_pipelineCache);
+    if (err != VK_SUCCESS)
+        qFatal("Failed to create pipeline cache: %d", err);
+
+    // Pipeline layout
+    VkPipelineLayoutCreateInfo pipelineLayoutInfo;
+    memset(&pipelineLayoutInfo, 0, sizeof(pipelineLayoutInfo));
+    pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
+    pipelineLayoutInfo.setLayoutCount = 1;
+    pipelineLayoutInfo.pSetLayouts = &m_descSetLayout;
+    err = m_devFuncs->vkCreatePipelineLayout(dev, &pipelineLayoutInfo, nullptr, &m_pipelineLayout);
+    if (err != VK_SUCCESS)
+        qFatal("Failed to create pipeline layout: %d", err);
+
+    // Shaders
+    VkShaderModule vertShaderModule = createShader(QStringLiteral(":/color_vert.spv"));
+    VkShaderModule fragShaderModule = createShader(QStringLiteral(":/color_frag.spv"));
+
+    // Graphics pipeline
+    VkGraphicsPipelineCreateInfo pipelineInfo;
+    memset(&pipelineInfo, 0, sizeof(pipelineInfo));
+    pipelineInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
+
+    VkPipelineShaderStageCreateInfo shaderStages[2] = {
+        {
+            VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,
+            nullptr,
+            0,
+            VK_SHADER_STAGE_VERTEX_BIT,
+            vertShaderModule,
+            "main",
+            nullptr
+        },
+        {
+            VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,
+            nullptr,
+            0,
+            VK_SHADER_STAGE_FRAGMENT_BIT,
+            fragShaderModule,
+            "main",
+            nullptr
+        }
+    };
+    pipelineInfo.stageCount = 2;
+    pipelineInfo.pStages = shaderStages;
+
+    pipelineInfo.pVertexInputState = &vertexInputInfo;
+
+    VkPipelineInputAssemblyStateCreateInfo ia;
+    memset(&ia, 0, sizeof(ia));
+    ia.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
+    ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
+    pipelineInfo.pInputAssemblyState = &ia;
+
+    // The viewport and scissor will be set dynamically via vkCmdSetViewport/Scissor.
+    // This way the pipeline does not need to be touched when resizing the window.
+    VkPipelineViewportStateCreateInfo vp;
+    memset(&vp, 0, sizeof(vp));
+    vp.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
+    vp.viewportCount = 1;
+    vp.scissorCount = 1;
+    pipelineInfo.pViewportState = &vp;
+
+    VkPipelineRasterizationStateCreateInfo rs;
+    memset(&rs, 0, sizeof(rs));
+    rs.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
+    rs.polygonMode = VK_POLYGON_MODE_FILL;
+    rs.cullMode = VK_CULL_MODE_NONE; // we want the back face as well
+    rs.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
+    rs.lineWidth = 1.0f;
+    pipelineInfo.pRasterizationState = &rs;
+
+    VkPipelineMultisampleStateCreateInfo ms;
+    memset(&ms, 0, sizeof(ms));
+    ms.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
+    // Enable multisampling.
+    ms.rasterizationSamples = m_window->sampleCountFlagBits();
+    pipelineInfo.pMultisampleState = &ms;
+
+    VkPipelineDepthStencilStateCreateInfo ds;
+    memset(&ds, 0, sizeof(ds));
+    ds.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
+    ds.depthTestEnable = VK_TRUE;
+    ds.depthWriteEnable = VK_TRUE;
+    ds.depthCompareOp = VK_COMPARE_OP_LESS_OR_EQUAL;
+    pipelineInfo.pDepthStencilState = &ds;
+
+    VkPipelineColorBlendStateCreateInfo cb;
+    memset(&cb, 0, sizeof(cb));
+    cb.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
+    // no blend, write out all of rgba
+    VkPipelineColorBlendAttachmentState att;
+    memset(&att, 0, sizeof(att));
+    att.colorWriteMask = 0xF;
+    cb.attachmentCount = 1;
+    cb.pAttachments = &att;
+    pipelineInfo.pColorBlendState = &cb;
+
+    VkDynamicState dynEnable[] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
+    VkPipelineDynamicStateCreateInfo dyn;
+    memset(&dyn, 0, sizeof(dyn));
+    dyn.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
+    dyn.dynamicStateCount = sizeof(dynEnable) / sizeof(VkDynamicState);
+    dyn.pDynamicStates = dynEnable;
+    pipelineInfo.pDynamicState = &dyn;
+
+    pipelineInfo.layout = m_pipelineLayout;
+    pipelineInfo.renderPass = m_window->defaultRenderPass();
+
+    err = m_devFuncs->vkCreateGraphicsPipelines(dev, m_pipelineCache, 1, &pipelineInfo, nullptr, &m_pipeline);
+    if (err != VK_SUCCESS)
+        qFatal("Failed to create graphics pipeline: %d", err);
+
+    if (vertShaderModule)
+        m_devFuncs->vkDestroyShaderModule(dev, vertShaderModule, nullptr);
+    if (fragShaderModule)
+        m_devFuncs->vkDestroyShaderModule(dev, fragShaderModule, nullptr);
+}
+
+void TriangleRenderer::initSwapChainResources()
+{
+    qDebug("initSwapChainResources");
+
+    // Projection matrix
+    m_proj = *m_window->clipCorrectionMatrix(); // adjust for Vulkan-OpenGL clip space differences
+    const QSize sz = m_window->swapChainImageSize();
+    m_proj.perspective(45.0f, sz.width() / (float) sz.height(), 0.01f, 100.0f);
+    m_proj.translate(0, 0, -4);
+}
+
+void TriangleRenderer::releaseSwapChainResources()
+{
+    qDebug("releaseSwapChainResources");
+}
+
+void TriangleRenderer::releaseResources()
+{
+    qDebug("releaseResources");
+
+    VkDevice dev = m_window->device();
+
+    if (m_pipeline) {
+        m_devFuncs->vkDestroyPipeline(dev, m_pipeline, nullptr);
+        m_pipeline = VK_NULL_HANDLE;
+    }
+
+    if (m_pipelineLayout) {
+        m_devFuncs->vkDestroyPipelineLayout(dev, m_pipelineLayout, nullptr);
+        m_pipelineLayout = VK_NULL_HANDLE;
+    }
+
+    if (m_pipelineCache) {
+        m_devFuncs->vkDestroyPipelineCache(dev, m_pipelineCache, nullptr);
+        m_pipelineCache = VK_NULL_HANDLE;
+    }
+
+    if (m_descSetLayout) {
+        m_devFuncs->vkDestroyDescriptorSetLayout(dev, m_descSetLayout, nullptr);
+        m_descSetLayout = VK_NULL_HANDLE;
+    }
+
+    if (m_descPool) {
+        m_devFuncs->vkDestroyDescriptorPool(dev, m_descPool, nullptr);
+        m_descPool = VK_NULL_HANDLE;
+    }
+
+    if (m_buf) {
+        m_devFuncs->vkDestroyBuffer(dev, m_buf, nullptr);
+        m_buf = VK_NULL_HANDLE;
+    }
+
+    if (m_bufMem) {
+        m_devFuncs->vkFreeMemory(dev, m_bufMem, nullptr);
+        m_bufMem = VK_NULL_HANDLE;
+    }
+}
+
+void TriangleRenderer::startNextFrame()
+{
+    VkDevice dev = m_window->device();
+    VkCommandBuffer cb = m_window->currentCommandBuffer();
+    const QSize sz = m_window->swapChainImageSize();
+
+    VkClearColorValue clearColor = { 0, 0, 0, 1 };
+    VkClearDepthStencilValue clearDS = { 1, 0 };
+    VkClearValue clearValues[3];
+    memset(clearValues, 0, sizeof(clearValues));
+    clearValues[0].color = clearValues[2].color = clearColor;
+    clearValues[1].depthStencil = clearDS;
+
+    VkRenderPassBeginInfo rpBeginInfo;
+    memset(&rpBeginInfo, 0, sizeof(rpBeginInfo));
+    rpBeginInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
+    rpBeginInfo.renderPass = m_window->defaultRenderPass();
+    rpBeginInfo.framebuffer = m_window->currentFramebuffer();
+    rpBeginInfo.renderArea.extent.width = sz.width();
+    rpBeginInfo.renderArea.extent.height = sz.height();
+    rpBeginInfo.clearValueCount = m_window->sampleCountFlagBits() > VK_SAMPLE_COUNT_1_BIT ? 3 : 2;
+    rpBeginInfo.pClearValues = clearValues;
+    VkCommandBuffer cmdBuf = m_window->currentCommandBuffer();
+    m_devFuncs->vkCmdBeginRenderPass(cmdBuf, &rpBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
+
+    quint8 *p;
+    VkResult err = m_devFuncs->vkMapMemory(dev, m_bufMem, m_uniformBufInfo[m_window->currentFrame()].offset,
+            UNIFORM_DATA_SIZE, 0, reinterpret_cast<void **>(&p));
+    if (err != VK_SUCCESS)
+        qFatal("Failed to map memory: %d", err);
+    QMatrix4x4 m = m_proj;
+    m.rotate(m_rotation, 0, 1, 0);
+    memcpy(p, m.constData(), 16 * sizeof(float));
+    m_devFuncs->vkUnmapMemory(dev, m_bufMem);
+
+    // Not exactly a real animation system, just advance on every frame for now.
+    m_rotation += 1.0f;
+
+    m_devFuncs->vkCmdBindPipeline(cb, VK_PIPELINE_BIND_POINT_GRAPHICS, m_pipeline);
+    m_devFuncs->vkCmdBindDescriptorSets(cb, VK_PIPELINE_BIND_POINT_GRAPHICS, m_pipelineLayout, 0, 1,
+                               &m_descSet[m_window->currentFrame()], 0, nullptr);
+    VkDeviceSize vbOffset = 0;
+    m_devFuncs->vkCmdBindVertexBuffers(cb, 0, 1, &m_buf, &vbOffset);
+
+    VkViewport viewport;
+    viewport.x = viewport.y = 0;
+    viewport.width = sz.width();
+    viewport.height = sz.height();
+    viewport.minDepth = 0;
+    viewport.maxDepth = 1;
+    m_devFuncs->vkCmdSetViewport(cb, 0, 1, &viewport);
+
+    VkRect2D scissor;
+    scissor.offset.x = scissor.offset.y = 0;
+    scissor.extent.width = viewport.width;
+    scissor.extent.height = viewport.height;
+    m_devFuncs->vkCmdSetScissor(cb, 0, 1, &scissor);
+
+    m_devFuncs->vkCmdDraw(cb, 3, 1, 0, 0);
+
+    m_devFuncs->vkCmdEndRenderPass(cmdBuf);
+
+    m_window->frameReady();
+    m_window->requestUpdate(); // render continuously, throttled by the presentation rate
+}