Scene Graph - Simple Material

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#include <qguiapplication.h> #include <qsgmaterial.h> #include <qsgnode.h> #include <qquickitem.h> #include <qquickview.h> #include <qsgsimplerectnode.h> #include <qsgsimplematerial.h> struct State { QColor color; int compare(const State *other) const { uint rgb = color.rgba(); uint otherRgb = other->color.rgba(); if (rgb == otherRgb) { return 0; } else if (rgb < otherRgb) { return -1; } else { return 1; } } }; class Shader : public QSGSimpleMaterialShader<State> { QSG_DECLARE_SIMPLE_COMPARABLE_SHADER(Shader, State); public: const char *vertexShader() const override { return "attribute highp vec4 aVertex; \n" "attribute highp vec2 aTexCoord; \n" "uniform highp mat4 qt_Matrix; \n" "varying highp vec2 texCoord; \n" "void main() { \n" " gl_Position = qt_Matrix * aVertex; \n" " texCoord = aTexCoord; \n" "}"; } const char *fragmentShader() const override { return "uniform lowp float qt_Opacity; \n" "uniform lowp vec4 color; \n" "varying highp vec2 texCoord; \n" "void main () \n" "{ \n" " gl_FragColor = texCoord.y * texCoord.x * color * qt_Opacity; \n" "}"; } QList<QByteArray> attributes() const override { return QList<QByteArray>() << "aVertex" << "aTexCoord"; } void updateState(const State *state, const State *) override { program()->setUniformValue(id_color, state->color); } void resolveUniforms() override { id_color = program()->uniformLocation("color"); } private: int id_color; }; class ColorNode : public QSGGeometryNode { public: ColorNode() : m_geometry(QSGGeometry::defaultAttributes_TexturedPoint2D(), 4) { setGeometry(&m_geometry); QSGSimpleMaterial<State> *material = Shader::createMaterial(); material->setFlag(QSGMaterial::Blending); setMaterial(material); setFlag(OwnsMaterial); } QSGGeometry m_geometry; }; class Item : public QQuickItem { Q_OBJECT Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged) public: Item() { setFlag(ItemHasContents, true); } void setColor(const QColor &color) { if (m_color != color) { m_color = color; emit colorChanged(); update(); } } QColor color() const { return m_color; } signals: void colorChanged(); private: QColor m_color; public: QSGNode *updatePaintNode(QSGNode *node, UpdatePaintNodeData *) override { ColorNode *n = static_cast<ColorNode *>(node); if (!node) n = new ColorNode(); QSGGeometry::updateTexturedRectGeometry(n->geometry(), boundingRect(), QRectF(0, 0, 1, 1)); static_cast<QSGSimpleMaterial<State>*>(n->material())->state()->color = m_color; n->markDirty(QSGNode::DirtyGeometry | QSGNode::DirtyMaterial); return n; } }; int main(int argc, char **argv) { QGuiApplication app(argc, argv); qmlRegisterType<Item>("SimpleMaterial", 1, 0, "SimpleMaterialItem"); QQuickView view; view.setResizeMode(QQuickView::SizeRootObjectToView); view.setSource(QUrl("qrc:///scenegraph/simplematerial/main.qml")); view.show(); return app.exec(); } #include "simplematerial.moc"