[Interest] How to use QSGSimpleTextureNode?

[Nuno Santos]

Hi,

I’m trying to render text on scene graph. My strategy consists in creating a texture with all the glyphs and then draw a specific subset of the texture for each glyph. I have already done this for iOS and Android native API’s but now, i’m porting my app to Qt/Qml and need to do it on scene graph.

My new node is extending QSGSimpleTextureNode. The code below is just for the most basic test purpose. 

unsigned char *data = (unsigned char*) malloc(ts*ts*4);
uint8_t * p = data;

for(int i=0; i<ts*ts; ++i)
{
    *p = 0; ++p;
    *p = 255; ++p;
    *p = 255; ++p;
    *p = 0; ++p;
}

glGenTextures(1, &_texture);

glBindTexture(GL_TEXTURE_2D, _texture);

glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, ts, ts, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);

// how do I set data to the texture?
setTexture()

free(data);

The essential question right now is how do I set my custom texture data to a texture? 

I have a Googled a lot about QSGSimpleTextureNode and QSGTexture but couldn’t find any clear example on how to do this.

Any thoughts?

Thanks,

Nuno Santos