new example: using compileManager to change between programs

examples/utils/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_subdirectory(vsgbuilder)
+add_subdirectory(vsgcompilemanager)
 add_subdirectory(vsggraphicspipelineconfigurator)
 add_subdirectory(vsgshaderset)
 add_subdirectory(vsgintersection)

examples/utils/vsgcompilemanager/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(SOURCES
+    vsgcompilemanager.cpp
+)
+
+add_executable(vsgcompilemanager ${SOURCES})
+
+target_link_libraries(vsgcompilemanager vsg::vsg)
+
+install(TARGETS vsgcompilemanager RUNTIME DESTINATION bin)

examples/utils/vsgcompilemanager/vsgcompilemanager.cpp

@@ -0,0 +1,174 @@
+#include <cassert>
+#include <string>
+
+#include "vsg/all.h"
+
+std::string VERT{R"(
+#version 450
+layout(push_constant) uniform PushConstants { mat4 projection; mat4 modelView; };
+layout(location = 0) in vec3 vertex;
+out gl_PerVertex { vec4 gl_Position; };
+void main() { gl_Position = (projection * modelView) * vec4(vertex, 1.0); }
+)"};
+
+std::string FRAG0{R"(
+#version 450
+layout(set = 0, binding = 0) buffer CellColors { vec4[] cellColors; };
+layout(location = 0) out vec4 color;
+void main() { color = cellColors[gl_PrimitiveID]; }
+)"};
+
+vsg::ref_ptr<vsg::StateGroup> createScene0()
+{
+    auto vertexShader = vsg::ShaderStage::create(VK_SHADER_STAGE_VERTEX_BIT, "main", VERT);
+    auto fragmentShader = vsg::ShaderStage::create(VK_SHADER_STAGE_FRAGMENT_BIT, "main", FRAG0);
+    auto shaderSet = vsg::ShaderSet::create(vsg::ShaderStages{vertexShader, fragmentShader});
+    shaderSet->addPushConstantRange("pc", "", VK_SHADER_STAGE_VERTEX_BIT, 0, 128);
+
+    shaderSet->addDescriptorBinding("cellColors", "", 0, 0,
+        VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1, VK_SHADER_STAGE_FRAGMENT_BIT,
+        vsg::vec4Array::create({{1,0,0,1}}));
+
+    shaderSet->addAttributeBinding("vertex", "", 0, VK_FORMAT_R32G32B32_SFLOAT,
+        vsg::vec3Array::create(1));
+
+    auto gpConf = vsg::GraphicsPipelineConfigurator::create(shaderSet);
+
+    /**
+     * This array is used in the fragment shader to color each individual triangle
+     * using gl_PrimitiveID as the array index. In principle, this could be
+     * a very large array that would exceed the uniform buffer size limits.
+     */
+    auto cellColors = vsg::vec4Array::create({
+        {0.176, 0.408, 0.376, 1.0},  // Powderkeg Blue (triangle 0)
+        {0.949, 0.663, 0.000, 1.0},  // Westwood Gold  (triangle 1)
+    });
+
+    gpConf->assignDescriptor("cellColors", cellColors);
+
+    /// single quad
+    auto vertices = vsg::vec3Array::create({
+        {-1, 0, -1}, { 1, 0, -1}, { 1, 0,  1}, {-1, 0,  1}
+    });
+    auto indices = vsg::uintArray::create({0, 1, 2, 0, 2, 3});
+    vsg::DataList vertexArrays;
+    gpConf->assignArray(vertexArrays, "vertex", VK_VERTEX_INPUT_RATE_VERTEX, vertices);
+
+    gpConf->init();
+
+    auto stateGroup = vsg::StateGroup::create();
+    gpConf->copyTo(stateGroup);
+
+    auto vertexDraw = vsg::VertexIndexDraw::create();
+    vertexDraw->assignArrays(vertexArrays);
+    vertexDraw->assignIndices(indices);
+    vertexDraw->indexCount = static_cast<uint32_t>(indices->size());
+    vertexDraw->instanceCount = 1;
+    stateGroup->addChild(vertexDraw);
+
+    return stateGroup;
+}
+
+std::string FRAG1{R"(
+#version 450
+layout(location = 0) out vec4 color;
+void main() { color = vec4(0.6, 0.6, 0.6, 1.0); }
+)"};
+
+vsg::ref_ptr<vsg::StateGroup> createScene1()
+{
+    auto vertexShader = vsg::ShaderStage::create(VK_SHADER_STAGE_VERTEX_BIT, "main", VERT);
+    auto fragmentShader = vsg::ShaderStage::create(VK_SHADER_STAGE_FRAGMENT_BIT, "main", FRAG1);
+    auto shaderSet = vsg::ShaderSet::create(vsg::ShaderStages{vertexShader, fragmentShader});
+    shaderSet->addPushConstantRange("pc", "", VK_SHADER_STAGE_VERTEX_BIT, 0, 128);
+
+    shaderSet->addAttributeBinding("vertex", "", 0, VK_FORMAT_R32G32B32_SFLOAT,
+        vsg::vec3Array::create(1));
+
+    auto gpConf = vsg::GraphicsPipelineConfigurator::create(shaderSet);
+
+    /// single quad
+    auto vertices = vsg::vec3Array::create({
+        {-1, 0, -1}, { 1, 0, -1}, { 1, 0,  1}, {-1, 0,  1}
+    });
+    auto indices = vsg::uintArray::create({0, 1, 2, 0, 2, 3});
+    vsg::DataList vertexArrays;
+    gpConf->assignArray(vertexArrays, "vertex", VK_VERTEX_INPUT_RATE_VERTEX, vertices);
+
+    gpConf->init();
+
+    auto stateGroup = vsg::StateGroup::create();
+    gpConf->copyTo(stateGroup);
+
+    auto vertexDraw = vsg::VertexIndexDraw::create();
+    vertexDraw->assignArrays(vertexArrays);
+    vertexDraw->assignIndices(indices);
+    vertexDraw->indexCount = static_cast<uint32_t>(indices->size());
+    vertexDraw->instanceCount = 1;
+    stateGroup->addChild(vertexDraw);
+
+    return stateGroup;
+}
+
+int main(int argc, char** argv)
+{
+    auto windowTraits = vsg::WindowTraits::create();
+    windowTraits->windowTitle = "vsgcompilemanager";
+    auto requestFeatures = windowTraits->deviceFeatures = vsg::DeviceFeatures::create();
+    requestFeatures->get().geometryShader = VK_TRUE;  // for gl_PrimitiveID
+
+    // set up defaults and read command line arguments to override them
+    vsg::CommandLine arguments(&argc, argv);
+    windowTraits->debugLayer = arguments.read({"--debug", "-d"});
+    windowTraits->apiDumpLayer = arguments.read({"--api", "-a"});
+
+    auto window = vsg::Window::create(windowTraits);
+    auto lookAt = vsg::LookAt::create(
+        vsg::dvec3{2,-5,-1},
+        vsg::dvec3{0, 0, 0},
+        vsg::dvec3{0, 0, 1}
+    );
+    auto perspective = vsg::Perspective::create();
+    auto viewportState = vsg::ViewportState::create(window->extent2D());
+    auto camera = vsg::Camera::create(perspective, lookAt, viewportState);
+    auto viewer = vsg::Viewer::create();
+
+    viewer->addWindow(window);
+    viewer->addEventHandler(vsg::CloseHandler::create(viewer));
+    viewer->addEventHandler(vsg::Trackball::create(camera));
+
+    auto sceneGraph = vsg::Group::create();
+    auto stateGroup = createScene0();
+    sceneGraph->addChild(stateGroup);
+
+    auto commandGraph = vsg::createCommandGraphForView(window, camera, sceneGraph);
+    viewer->assignRecordAndSubmitTaskAndPresentation({commandGraph});
+    viewer->compile();
+
+    int sceneNumber{0};
+    int frameCount{0};
+    while (viewer->advanceToNextFrame())
+    {
+        if ((++frameCount % 60) == 0) {
+            viewer->deviceWaitIdle();
+            sceneGraph->children.clear();
+            if (sceneNumber == 0) {
+                sceneNumber = 1;
+                stateGroup = createScene1();
+            } else {
+                sceneNumber = 0;
+                stateGroup = createScene0();
+            }
+
+            sceneGraph->addChild(stateGroup);
+            auto result = viewer->compileManager->compile(sceneGraph);
+            assert(result.result == VK_SUCCESS);
+            vsg::updateViewer(*viewer, result);
+        }
+
+        viewer->handleEvents();
+        viewer->update();
+        viewer->recordAndSubmit();
+        viewer->present();
+    }
+}