simplematerial.cpp Example File
scenegraph/simplematerial/simplematerial.cpp
#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"