func (c *graphicsContext) setSize(screenWidth, screenHeight, screenScale int) error {
if c.defaultRenderTarget != nil {
c.defaultRenderTarget.dispose()
}
if c.screen != nil {
c.screen.dispose()
}
var err error
useGLContext(func(g *opengl.Context) {
f, err := graphics.NewZeroFramebuffer(g, screenWidth*screenScale, screenHeight*screenScale)
if err != nil {
return
}
texture, err := graphics.NewTexture(g, screenWidth, screenHeight, g.Nearest)
if err != nil {
return
}
screenF, err := graphics.NewFramebufferFromTexture(g, texture)
if err != nil {
return
}
screen := &Image{framebuffer: screenF, texture: texture}
c.defaultRenderTarget = &Image{framebuffer: f, texture: nil}
c.screen = screen
c.screenScale = screenScale
})
return err
}
// NewImage returns an empty image.
//
// NewImage generates a new texture and a new framebuffer.
// Be careful that image objects will never be released
// even though nothing refers the image object and GC works.
// It is because there is no way to define finalizers for Go objects if you use GopherJS.
func NewImage(width, height int, filter Filter) (*Image, error) {
var img *Image
var err error
useGLContext(func(c *opengl.Context) {
var texture *graphics.Texture
var framebuffer *graphics.Framebuffer
texture, err = graphics.NewTexture(c, width, height, glFilter(c, filter))
if err != nil {
return
}
framebuffer, err = graphics.NewFramebufferFromTexture(c, texture)
if err != nil {
return
}
img = &Image{framebuffer: framebuffer, texture: texture}
})
if err != nil {
return nil, err
}
if err := img.Clear(); err != nil {
return nil, err
}
return img, nil
}