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authorLaszlo Agocs <laszlo.agocs@qt.io>2023-04-27 13:16:29 +0200
committerLaszlo Agocs <laszlo.agocs@qt.io>2023-05-21 15:42:58 +0200
commit1dd8b5ceec3a1cde987372a7f993c07f30e5af95 (patch)
tree53e8b96c8a2bf104573a45958329255a5abcd4d9 /src/gui/doc/snippets/rhioffscreen/main.cpp
parent30a8e79243084017d23f1c765d5f1cbb86564191 (diff)
rhi: Make it a QPA-style private but semi-public API
qrhi.h, qshader.h, qshaderdescription.h (and qshaderbaker.h from shadertools; done separately) become "RHI APIs", following the concept of QPA APIs. Mirror completely what is done for QPA headers, but using the "rhi" prefix for the headers. This involves updating syncqt to handle the new category of headers. (a note on the regex: matching everything starting with "qrhi" is not acceptable due to incorrectly matching existing and future headers, hence specifying the four header names explicitly) There is going to be one difference to QPA: the documentation for everything RHI is going to be public and part of the regular docs, not hidden with \internal. In addition to the header renaming and adding the comments and documentation notes and warnings, there is one significant change here: there is no longer a need to do API-specific includes, such as qrhid3d11[_p].h, qrhivulkan[_p].h, etc. These are simply merged into a single header that is then included from qrhi.h. This means that users within Qt, and any future applications can just do #include <rhi/qrhi.h> (or rhi/qshader.h if the QRhi stuff is not relevant), no other headers are needed. There are no changes to functionality in this patch. Only the documentation is expanded, quite a lot, to eliminate all qdoc warnings and make the generated API docs complete. An example, with a quite extensive doc page is added as well. Task-number: QTBUG-113331 Change-Id: I91c749826348f14320cb335b1c83e9d1ea2b1d8b Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io> Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Diffstat (limited to 'src/gui/doc/snippets/rhioffscreen/main.cpp')
-rw-r--r--src/gui/doc/snippets/rhioffscreen/main.cpp151
1 files changed, 151 insertions, 0 deletions
diff --git a/src/gui/doc/snippets/rhioffscreen/main.cpp b/src/gui/doc/snippets/rhioffscreen/main.cpp
new file mode 100644
index 00000000000..b3fac4b5201
--- /dev/null
+++ b/src/gui/doc/snippets/rhioffscreen/main.cpp
@@ -0,0 +1,151 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+//! [0]
+#include <QGuiApplication>
+#include <QImage>
+#include <QFile>
+#include <rhi/qrhi.h>
+
+int main(int argc, char **argv)
+{
+ QGuiApplication app(argc, argv);
+
+ std::unique_ptr<QRhi> rhi;
+#if defined(Q_OS_WIN)
+ QRhiD3D12InitParams params;
+ rhi.reset(QRhi::create(QRhi::D3D12, &params));
+#elif defined(Q_OS_MACOS) || defined(Q_OS_IOS)
+ QRhiMetalInitParams params;
+ rhi.reset(QRhi::create(QRhi::Metal, &params));
+#elif QT_CONFIG(vulkan)
+ QVulkanInstance inst;
+ inst.setExtensions(QRhiVulkanInitParams::preferredInstanceExtensions());
+ if (inst.create()) {
+ QRhiVulkanInitParams params;
+ params.inst = &inst;
+ rhi.reset(QRhi::create(QRhi::Vulkan, &params));
+ } else {
+ qFatal("Failed to create Vulkan instance");
+ }
+#endif
+ if (rhi)
+ qDebug() << rhi->backendName() << rhi->driverInfo();
+ else
+ qFatal("Failed to initialize RHI");
+
+ float rotation = 0.0f;
+ float opacity = 1.0f;
+ int opacityDir = 1;
+
+ std::unique_ptr<QRhiTexture> tex(rhi->newTexture(QRhiTexture::RGBA8,
+ QSize(1280, 720),
+ 1,
+ QRhiTexture::RenderTarget | QRhiTexture::UsedAsTransferSource));
+ tex->create();
+ std::unique_ptr<QRhiTextureRenderTarget> rt(rhi->newTextureRenderTarget({ tex.get() }));
+ std::unique_ptr<QRhiRenderPassDescriptor> rp(rt->newCompatibleRenderPassDescriptor());
+ rt->setRenderPassDescriptor(rp.get());
+ rt->create();
+
+ QMatrix4x4 viewProjection = rhi->clipSpaceCorrMatrix();
+ viewProjection.perspective(45.0f, 1280 / 720.f, 0.01f, 1000.0f);
+ viewProjection.translate(0, 0, -4);
+
+ static float vertexData[] = { // Y up, CCW
+ 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,
+ };
+
+ std::unique_ptr<QRhiBuffer> vbuf(rhi->newBuffer(QRhiBuffer::Immutable,
+ QRhiBuffer::VertexBuffer,
+ sizeof(vertexData)));
+ vbuf->create();
+
+ std::unique_ptr<QRhiBuffer> ubuf(rhi->newBuffer(QRhiBuffer::Dynamic,
+ QRhiBuffer::UniformBuffer,
+ 64 + 4));
+ ubuf->create();
+
+ std::unique_ptr<QRhiShaderResourceBindings> srb(rhi->newShaderResourceBindings());
+ srb->setBindings({
+ QRhiShaderResourceBinding::uniformBuffer(0,
+ QRhiShaderResourceBinding::VertexStage | QRhiShaderResourceBinding::FragmentStage,
+ ubuf.get())
+ });
+ srb->create();
+
+ std::unique_ptr<QRhiGraphicsPipeline> ps(rhi->newGraphicsPipeline());
+ QRhiGraphicsPipeline::TargetBlend premulAlphaBlend;
+ premulAlphaBlend.enable = true;
+ ps->setTargetBlends({ premulAlphaBlend });
+ static auto getShader = [](const QString &name) {
+ QFile f(name);
+ if (f.open(QIODevice::ReadOnly))
+ return QShader::fromSerialized(f.readAll());
+ return QShader();
+ };
+ ps->setShaderStages({
+ { QRhiShaderStage::Vertex, getShader(QLatin1String("color.vert.qsb")) },
+ { QRhiShaderStage::Fragment, getShader(QLatin1String("color.frag.qsb")) }
+ });
+ QRhiVertexInputLayout inputLayout;
+ inputLayout.setBindings({
+ { 5 * sizeof(float) }
+ });
+ inputLayout.setAttributes({
+ { 0, 0, QRhiVertexInputAttribute::Float2, 0 },
+ { 0, 1, QRhiVertexInputAttribute::Float3, 2 * sizeof(float) }
+ });
+ ps->setVertexInputLayout(inputLayout);
+ ps->setShaderResourceBindings(srb.get());
+ ps->setRenderPassDescriptor(rp.get());
+ ps->create();
+
+ QRhiCommandBuffer *cb;
+ for (int frame = 0; frame < 20; ++frame) {
+ rhi->beginOffscreenFrame(&cb);
+
+ QRhiResourceUpdateBatch *u = rhi->nextResourceUpdateBatch();
+ if (frame == 0)
+ u->uploadStaticBuffer(vbuf.get(), vertexData);
+
+ QMatrix4x4 mvp = viewProjection;
+ mvp.rotate(rotation, 0, 1, 0);
+ u->updateDynamicBuffer(ubuf.get(), 0, 64, mvp.constData());
+ rotation += 5.0f;
+
+ u->updateDynamicBuffer(ubuf.get(), 64, 4, &opacity);
+ opacity += opacityDir * 0.2f;
+ if (opacity < 0.0f || opacity > 1.0f) {
+ opacityDir *= -1;
+ opacity = qBound(0.0f, opacity, 1.0f);
+ }
+
+ cb->beginPass(rt.get(), Qt::green, { 1.0f, 0 }, u);
+ cb->setGraphicsPipeline(ps.get());
+ cb->setViewport({ 0, 0, 1280, 720 });
+ cb->setShaderResources();
+ const QRhiCommandBuffer::VertexInput vbufBinding(vbuf.get(), 0);
+ cb->setVertexInput(0, 1, &vbufBinding);
+ cb->draw(3);
+ QRhiReadbackResult readbackResult;
+ u = rhi->nextResourceUpdateBatch();
+ u->readBackTexture({ tex.get() }, &readbackResult);
+ cb->endPass(u);
+
+ rhi->endOffscreenFrame();
+
+ QImage image(reinterpret_cast<const uchar *>(readbackResult.data.constData()),
+ readbackResult.pixelSize.width(),
+ readbackResult.pixelSize.height(),
+ QImage::Format_RGBA8888_Premultiplied);
+ if (rhi->isYUpInFramebuffer())
+ image = image.mirrored();
+ image.save(QString::asprintf("frame%d.png", frame));
+ }
+
+ return 0;
+}
+//! [0]
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