rhi: Add texture array support

Arrays of textures have always been supported, but we will encounter
cases when we need to work with texture array objects as well.

Note that currently it is not possible to expose only a slice of the
array to the shader, because there is no dedicated API in the SRB,
and thus the same SRV/UAV (or equivalent) is used always, capturing
all elements in the array. Therefore in the shader the last component
of P in texture() is in range 0..array_size-1.

Change-Id: I5a032ed016aeefbbcd743d5bfb9fbc49ba00a1fa
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

9 files changed, 278 insertions, 2 deletions

diff --git a/tests/manual/rhi/CMakeLists.txt b/tests/manual/rhi/CMakeLists.txt
index f8879bbd0f..11117a00ae 100644
--- a/tests/manual/rhi/CMakeLists.txt
+++ b/tests/manual/rhi/CMakeLists.txt
@@ -22,6 +22,7 @@ add_subdirectory(computeimage)
 add_subdirectory(instancing)
 add_subdirectory(noninstanced)
 add_subdirectory(tex3d)
+add_subdirectory(texturearray)
 if(QT_FEATURE_widgets)
     add_subdirectory(qrhiprof)
 endif()
diff --git a/tests/manual/rhi/shared/buildshaders.bat b/tests/manual/rhi/shared/buildshaders.bat
index 7974683bd7..d0212bc7a7 100644
--- a/tests/manual/rhi/shared/buildshaders.bat
+++ b/tests/manual/rhi/shared/buildshaders.bat
@@ -3,3 +3,5 @@ qsb --glsl "100 es,120" --hlsl 50 --msl 12 -c color.frag -o color.frag.qsb
 qsb --glsl "100 es,120" --hlsl 50 --msl 12 -c texture.vert -o texture.vert.qsb
 qsb --glsl "100 es,120" --hlsl 50 --msl 12 -c texture.frag -o texture.frag.qsb
 qsb --glsl "310 es,150" --hlsl 50 --msl 12 -c texture_ms4.frag -o texture_ms4.frag.qsb
+qsb --glsl "100 es,120,150" --hlsl 50 --msl 12 -c texture_arr.vert -o texture_arr.vert.qsb
+qsb --glsl "100 es,120,150" --hlsl 50 --msl 12 -c texture_arr.frag -o texture_arr.frag.qsb
diff --git a/tests/manual/rhi/shared/examplefw.h b/tests/manual/rhi/shared/examplefw.h
index 83b5a73514..e7bc3e6b5d 100644
--- a/tests/manual/rhi/shared/examplefw.h
+++ b/tests/manual/rhi/shared/examplefw.h
@@ -109,7 +109,7 @@ QString graphicsApiName()
     case Null:
         return QLatin1String("Null (no output)");
     case OpenGL:
-        return QLatin1String("OpenGL 2.x");
+        return QLatin1String("OpenGL");
     case Vulkan:
         return QLatin1String("Vulkan");
     case D3D11:
@@ -462,7 +462,7 @@ int main(int argc, char **argv)
     cmdLineParser.addHelpOption();
     QCommandLineOption nullOption({ "n", "null" }, QLatin1String("Null"));
     cmdLineParser.addOption(nullOption);
-    QCommandLineOption glOption({ "g", "opengl" }, QLatin1String("OpenGL (2.x)"));
+    QCommandLineOption glOption({ "g", "opengl" }, QLatin1String("OpenGL"));
     cmdLineParser.addOption(glOption);
     QCommandLineOption vkOption({ "v", "vulkan" }, QLatin1String("Vulkan"));
     cmdLineParser.addOption(vkOption);
@@ -475,6 +475,8 @@ int main(int argc, char **argv)
     // Use this parameter for the latter.
     QCommandLineOption sdOption({ "s", "self-destruct" }, QLatin1String("Self-destruct after 5 seconds."));
     cmdLineParser.addOption(sdOption);
+    QCommandLineOption coreProfOption({ "c", "core" }, QLatin1String("Request a core profile context for OpenGL"));
+    cmdLineParser.addOption(coreProfOption);
     // Attempt testing device lost situations on D3D at least.
     QCommandLineOption tdrOption(QLatin1String("curse"), QLatin1String("Curse the graphics device. "
                                                         "(generate a device reset every <count> frames when on D3D11)"),
@@ -517,6 +519,14 @@ int main(int argc, char **argv)
     QSurfaceFormat fmt;
     fmt.setDepthBufferSize(24);
     fmt.setStencilBufferSize(8);
+    if (cmdLineParser.isSet(coreProfOption)) {
+#ifdef Q_OS_DARWIN
+        fmt.setVersion(4, 1);
+#else
+        fmt.setVersion(4, 3);
+#endif
+        fmt.setProfile(QSurfaceFormat::CoreProfile);
+    }
     if (sampleCount > 1)
         fmt.setSamples(sampleCount);
     if (scFlags.testFlag(QRhiSwapChain::NoVSync))
diff --git a/tests/manual/rhi/shared/texture_arr.frag b/tests/manual/rhi/shared/texture_arr.frag
new file mode 100644
index 0000000000..0a2631e2bd
--- /dev/null
+++ b/tests/manual/rhi/shared/texture_arr.frag
@@ -0,0 +1,19 @@
+#version 440
+
+layout(location = 0) in vec2 v_texcoord;
+
+layout(location = 0) out vec4 fragColor;
+
+layout(std140, binding = 0) uniform buf {
+    mat4 mvp;
+    int flip;
+    int array_index;
+};
+
+layout(binding = 1) uniform sampler2DArray texArr;
+
+void main()
+{
+    vec4 c = texture(texArr, vec3(v_texcoord, float(array_index)));
+    fragColor = vec4(c.rgb * c.a, c.a);
+}
diff --git a/tests/manual/rhi/shared/texture_arr.frag.qsb b/tests/manual/rhi/shared/texture_arr.frag.qsb
new file mode 100644
index 0000000000..3674fdad1d
--- /dev/null
+++ b/tests/manual/rhi/shared/texture_arr.frag.qsb
diff --git a/tests/manual/rhi/shared/texture_arr.vert b/tests/manual/rhi/shared/texture_arr.vert
new file mode 100644
index 0000000000..137263e080
--- /dev/null
+++ b/tests/manual/rhi/shared/texture_arr.vert
@@ -0,0 +1,20 @@
+#version 440
+
+layout(location = 0) in vec4 position;
+layout(location = 1) in vec2 texcoord;
+
+layout(location = 0) out vec2 v_texcoord;
+
+layout(std140, binding = 0) uniform buf {
+    mat4 mvp;
+    int flip;
+    int array_index;
+};
+
+void main()
+{
+    v_texcoord = vec2(texcoord.x, texcoord.y);
+    if (flip != 0)
+        v_texcoord.y = 1.0 - v_texcoord.y;
+    gl_Position = mvp * position;
+}
diff --git a/tests/manual/rhi/shared/texture_arr.vert.qsb b/tests/manual/rhi/shared/texture_arr.vert.qsb
new file mode 100644
index 0000000000..fe46d2c385
--- /dev/null
+++ b/tests/manual/rhi/shared/texture_arr.vert.qsb
diff --git a/tests/manual/rhi/texturearray/CMakeLists.txt b/tests/manual/rhi/texturearray/CMakeLists.txt
new file mode 100644
index 0000000000..39e49d5287
--- /dev/null
+++ b/tests/manual/rhi/texturearray/CMakeLists.txt
@@ -0,0 +1,26 @@
+qt_internal_add_manual_test(texturearray
+    GUI
+    SOURCES
+        texturearray.cpp
+    PUBLIC_LIBRARIES
+        Qt::Gui
+        Qt::GuiPrivate
+)
+
+set_source_files_properties("../shared/texture_arr.vert.qsb"
+    PROPERTIES QT_RESOURCE_ALIAS "texture_arr.vert.qsb"
+)
+set_source_files_properties("../shared/texture_arr.frag.qsb"
+    PROPERTIES QT_RESOURCE_ALIAS "texture_arr.frag.qsb"
+)
+set(texturearray_resource_files
+    "../shared/texture_arr.vert.qsb"
+    "../shared/texture_arr.frag.qsb"
+)
+
+qt_internal_add_resource(texturearray "texturearray"
+    PREFIX
+        "/"
+    FILES
+        ${texturearray_resource_files}
+)
diff --git a/tests/manual/rhi/texturearray/texturearray.cpp b/tests/manual/rhi/texturearray/texturearray.cpp
new file mode 100644
index 0000000000..206730464e
--- /dev/null
+++ b/tests/manual/rhi/texturearray/texturearray.cpp
@@ -0,0 +1,198 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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 "../shared/examplefw.h"
+#include <QElapsedTimer>
+
+// Creates a texture array object with size 4, uploads a different
+// image to each, and cycles through them on-screen.
+
+static const int ARRAY_SIZE = 4;
+static const int UBUF_SIZE = 72;
+
+static float vertexData[] =
+{ // Y up, CCW
+  -0.5f,   0.5f,   0.0f, 0.0f,
+  -0.5f,  -0.5f,   0.0f, 1.0f,
+  0.5f,   -0.5f,   1.0f, 1.0f,
+  0.5f,   0.5f,    1.0f, 0.0f
+};
+
+static quint16 indexData[] =
+{
+    0, 1, 2, 0, 2, 3
+};
+
+struct {
+    QList<QRhiResource *> releasePool;
+    QRhiTexture *texArr = nullptr;
+    QRhiSampler *sampler = nullptr;
+    QRhiShaderResourceBindings *srb = nullptr;
+    QRhiBuffer *vbuf = nullptr;
+    QRhiBuffer *ibuf = nullptr;
+    QRhiBuffer *ubuf = nullptr;
+    QRhiGraphicsPipeline *ps = nullptr;
+    QRhiResourceUpdateBatch *initialUpdates = nullptr;
+    QMatrix4x4 winProj;
+    QElapsedTimer t;
+    int arrayIndex = 0;
+} d;
+
+void Window::customInit()
+{
+    if (!m_r->isFeatureSupported(QRhi::TextureArrays))
+        qFatal("Texture array objects are not supported by this backend");
+
+    d.texArr = m_r->newTextureArray(QRhiTexture::RGBA8, ARRAY_SIZE, QSize(512, 512));
+    d.releasePool << d.texArr;
+    d.texArr->create();
+
+    d.initialUpdates = m_r->nextResourceUpdateBatch();
+
+    QImage img(512, 512, QImage::Format_RGBA8888);
+    img.fill(Qt::red);
+    d.initialUpdates->uploadTexture(d.texArr, QRhiTextureUploadDescription(QRhiTextureUploadEntry(0, 0, QRhiTextureSubresourceUploadDescription(img))));
+    img.fill(Qt::green);
+    d.initialUpdates->uploadTexture(d.texArr, QRhiTextureUploadDescription(QRhiTextureUploadEntry(1, 0, QRhiTextureSubresourceUploadDescription(img))));
+    img.fill(Qt::blue);
+    d.initialUpdates->uploadTexture(d.texArr, QRhiTextureUploadDescription(QRhiTextureUploadEntry(2, 0, QRhiTextureSubresourceUploadDescription(img))));
+    img.fill(Qt::yellow);
+    d.initialUpdates->uploadTexture(d.texArr, QRhiTextureUploadDescription(QRhiTextureUploadEntry(3, 0, QRhiTextureSubresourceUploadDescription(img))));
+
+    d.sampler = m_r->newSampler(QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
+                                QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge);
+    d.releasePool << d.sampler;
+    d.sampler->create();
+
+    d.ubuf = m_r->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, UBUF_SIZE);
+    d.releasePool << d.ubuf;
+    d.ubuf->create();
+
+    d.srb = m_r->newShaderResourceBindings();
+    d.releasePool << d.srb;
+    d.srb->setBindings({
+        QRhiShaderResourceBinding::uniformBuffer(0, QRhiShaderResourceBinding::VertexStage | QRhiShaderResourceBinding::FragmentStage, d.ubuf, 0, UBUF_SIZE),
+        QRhiShaderResourceBinding::sampledTexture(1, QRhiShaderResourceBinding::FragmentStage, d.texArr, d.sampler)
+    });
+    d.srb->create();
+
+    d.vbuf = m_r->newBuffer(QRhiBuffer::Immutable, QRhiBuffer::VertexBuffer, sizeof(vertexData));
+    d.releasePool << d.vbuf;
+    d.vbuf->create();
+
+    d.ibuf = m_r->newBuffer(QRhiBuffer::Immutable, QRhiBuffer::IndexBuffer, sizeof(indexData));
+    d.releasePool << d.ibuf;
+    d.ibuf->create();
+
+    d.initialUpdates->uploadStaticBuffer(d.vbuf, 0, sizeof(vertexData), vertexData);
+    d.initialUpdates->uploadStaticBuffer(d.ibuf, indexData);
+
+    d.ps = m_r->newGraphicsPipeline();
+    d.releasePool << d.ps;
+    d.ps->setShaderStages({
+        { QRhiShaderStage::Vertex, getShader(QLatin1String(":/texture_arr.vert.qsb")) },
+        { QRhiShaderStage::Fragment, getShader(QLatin1String(":/texture_arr.frag.qsb")) }
+    });
+    QRhiVertexInputLayout inputLayout;
+    inputLayout.setBindings({ { 4 * sizeof(float) } });
+    inputLayout.setAttributes({
+        { 0, 0, QRhiVertexInputAttribute::Float2, 0 },
+        { 0, 1, QRhiVertexInputAttribute::Float2, quint32(2 * sizeof(float)) }
+    });
+    d.ps->setVertexInputLayout(inputLayout);
+    d.ps->setShaderResourceBindings(d.srb);
+    d.ps->setRenderPassDescriptor(m_rp);
+    d.ps->create();
+
+    d.t.start();
+}
+
+void Window::customRelease()
+{
+    qDeleteAll(d.releasePool);
+    d.releasePool.clear();
+}
+
+void Window::customRender()
+{
+    QRhiCommandBuffer *cb = m_sc->currentFrameCommandBuffer();
+    QRhiResourceUpdateBatch *u = m_r->nextResourceUpdateBatch();
+    if (d.initialUpdates) {
+        u->merge(d.initialUpdates);
+        d.initialUpdates->release();
+        d.initialUpdates = nullptr;
+    }
+
+    if (d.winProj != m_proj) {
+        d.winProj = m_proj;
+        QMatrix4x4 mvp = m_proj;
+        mvp.scale(2);
+        u->updateDynamicBuffer(d.ubuf, 0, 64, mvp.constData());
+        const qint32 flip = 0;
+        u->updateDynamicBuffer(d.ubuf, 64, 4, &flip);
+        u->updateDynamicBuffer(d.ubuf, 68, 4, &d.arrayIndex);
+    }
+
+    if (d.t.elapsed() > 2000) {
+        d.t.restart();
+        d.arrayIndex = (d.arrayIndex + 1) % ARRAY_SIZE;
+        u->updateDynamicBuffer(d.ubuf, 68, 4, &d.arrayIndex);
+    }
+
+    const QSize outputSizeInPixels = m_sc->currentPixelSize();
+    cb->beginPass(m_sc->currentFrameRenderTarget(), m_clearColor, { 1.0f, 0 }, u);
+    cb->setGraphicsPipeline(d.ps);
+    cb->setViewport({ 0, 0, float(outputSizeInPixels.width()), float(outputSizeInPixels.height()) });
+    cb->setShaderResources();
+    QRhiCommandBuffer::VertexInput vbufBinding(d.vbuf, 0);
+    cb->setVertexInput(0, 1, &vbufBinding, d.ibuf, 0, QRhiCommandBuffer::IndexUInt16);
+    cb->drawIndexed(6);
+    cb->endPass();
+}