Can not find python function (either gimp.xxxx() or pdb.gimp_xxxxx() ) that will actually APPLY the gradient selected as current with either
gimp.gradients_set_active(<gradientName>) (which seems to have disappeared) or
pdb.gimp_context_set_gradient(<gradientName>)
I have seemingly spent an eternity browsing the web, s.o., and the gimp procedural database to find something that will actually FILL a LAYER/drawable/selection with a GRADIENT along a PATH with no success.
the pdb fill functions have an option for pattern fill, but no gradient and no stroke path.
the pdb stroke functions only apply the current foreground along a path.
everything on the web is about >creating< a gradient -- but I have the gradients - just no way to apply/fill/stroke them from a script.
code: SEE above
It appears that gimp_edit_blend() is the pdb function to actually fill a drawable with a gradient.
The context gradient must be set before-hand (as in the question).
And, it appears that the blend_mode parameter (the second parameter) must be 3, (ie CUSTOM-MODE) ->
pdb.gimp_edit_blend(drawable, blend_mode, ...)
To fill a layer with a gradient, the proper function is pdb.gimp_drawable_edit_gradient_fill().
To use a gradient along path, use pdb.gimp_paintbrush() where the last argument is the "fade" length. Of course this call takes a sequence of straight segments and not a path, but you can transform a path stroke into a sequence of segments using pdb.gimp_vectors_stroke_interpolate().
Related
I want to create a vtkGlyph3D from a vtkPolyData containing points, triangles and colors
polydata->SetPoints(points);
polydata->SetPolys(triangles);
polydata->GetPointData()->SetScalars(colors);
Now in all the examples for vtkGlyph3D there is always the call to SetSourceConnection to which a vtkAlgorithmOutput object is passed.
Since i don't use a vtkCubeSource or vtkConeSource or the like, i don't know what i should pass here.
Can i just omit this call and simply do this
vtkNew<vtkGlyph3D> glyph3D;
glyph3D->SetColorModeToColorByScalar();
glyph3D->SetInputData(polydata);
glyph3D->ScalingOff();
glyph3D->Update();
to build my glyph?
Or do i somehow have to create a vtkAlgorithmOutput from my polydata?
From the doc, vtkGlyph3D
copy oriented and scaled glyph geometry to every input point
In other word, this filter copy the Source geometry on every (Nth) points of your Input (and some more option of scale / orientation). So it does not make sense to use it without a SetSourceConnection (with any kind of source/reader/filter providing a polydata)
I am building a simple Solar system model and trying to set textures on some spheres.
The geometry is properly generated, and I tried a couple different ways to generate the texture coordinates. At present I am relying on glu:quadric-texture for generating the coordinates when glu:sphere is called.
However, the textures never appear - objects are rendered in flat colors.
I went through several OpenGL guides and I do not think I am missing a step, but who knows.
Here is what is roughly happening:
call gl:enable :texture-2d to turn on textures
load images using cl-jpeg
call gl:bind-texture
copy data from image using gl:tex-image-2d
generate texture ids with gl:gen-textures. Also tried generating ids one by one instead of all at once, which had no effect.
during drawing create new quadric, enable texture coordinates generation and bind the texture before generating the quadric points:
(let ((q (glu:new-quadric)))
(if (planet-state-texture-id ps)
(progn (gl:enable :texture-gen-s)
(gl:enable :texture-gen-t)
(glu:quadric-texture q :true)
(gl:bind-texture :texture-2d planet-texture-id)))
(glu:quadric-texture q :false))
(glu:sphere q
planet-diameter
*sphere-resolution*
*sphere-resolution*)
I also tried a more manual method of texture coordinates generation, which had no effect.
Out of ideas here…
make-texture function
texture id generation
quadric drawing
When the program runs, I can see the textures are loaded and texture ids are reserved, it prints
loading texture from textures/2k_neptune.jpg with id 1919249769
Loaded data. Image dimensions: 1024x2048
I don't know if you've discovered a solution to your problem, but after creating a test image, and modifying some of your code, I was able to get the texture to be applied to the sphere.
The problem comes into play with the fact that you are attempting to upload textures to the GPU before you've enabled them. (gl:enable :texture-2d) has to be called before you start handling texture/image data.
I'd recommend putting the let* block with the planets-init that is in the main function after 'setup-gl', and also moving the 'format' function with the planets data to work correctly without an error coming up.
My recommendation is something like:
(let ((camera ...
...
(setup-gl ...)
(let* ((planets...
...
(format ... planet-state)
In your draw-planet function, you'll want to add (gl:bind-texture :texture-2d 0) at the end of it so that the texture isn't used for another object, like the orbital path.
As is, the (gl:color 1.0 ...) before the (gl:quadratic-texture ...) will modify the color of the rendered object, so it may not look like what you're expecting it to look like.
Edit: I should've clarified this, but as your code stands it goes
initialize-planets > make-textures > enable-textures > render
When it should be
enable-textures > init-planets > make-textures > render
You're correct about not missing a step, the steps in your code are just misordered.
So, the question looks simple, but I still can't understand how properly compute a vertical alignment of glyphs when we use SDF generated bitmaps using stb_truetype library.
In nutshell I have own texture packer system that generates a texture atlas with all needed SDF represented glyphs. Also there is a data type that contains the following parameters per code point including width, height, xoff and yoff, which I get from stbtt_GetCodepointSDF function.
I've checked up a few listings including this one, but it didn't help me. So what's the right formula?
I have a CCSprite which gradually needs to be exhausted linearly from one end, lets say from left to right.For this purpose ,I am trying to change the textureRect property of the sprite so that the part that got exhausted from one end is 'outside' the displaying frame of the sprite.
I did this sort of thing before with a sprite that gets loaded from a spritesheet.And it worked perfectly.But I created this CCSprite using CCRenderTexture and by changing the textureRect property,the entire sprite gets disappeared.
The first image is the original CCSprite which I get from CCRenderTexture.The second image shows what I want to achieve.The black dotted rectangular portion of the Sprite needs to be omitted out.Only the blue dotted portion of the sprite needs to be displayed.Essentially,this blue dotted rectangle is my textureRect.
Is there any way how I could make my sprite reduce from one end.
Also is there any difference between a sprite created normally,and one created using CCRenderTexture.
I have done similar thing like this before using some low-level hack.
There is a work around solution if you use CCProgressTimer, that's very easy and I think it should be enough for your examples.
But you said in comment that you have some special requirements like "exhaust it from both the ends at once" then some low-level hack is needed. My solution from my last object is:
1) Get the texture image's raw data. In cocos2d you can use CCRenderTexture and in cocos2d-x you can use CCImage.
2) CCRenderTexture has a method of - (BOOL) saveToFile: (NSString *) name
format: (tCCImageFormat) format
. You can read its source code then try to save it into an 2D array instead like byte raw[1024][768]. Each element in this array represents one pixel on your picture(the type may not be byte, I'm not sure, nearly forget the details). The format MUST BE PNG since transparency will be needed.
3) Modify raw data directly, set pixel's transparency to 0x0 which you want it to disappear.
4) Re-initialize a CCRenderTexture using picture data you modified.
I can't provide the code directly since is a trade secret and core part of one of my projects. But I can share you my solution. You also need some knowledge about how PNG file works. Read:
https://en.wikipedia.org/wiki/Portable_Network_Graphics#File_header
Turns out I was making a silly mistake.While supplying values to the textureRect(CGRect),I was actually setting the textureRect.origin.y to the height of the texture which made my textureRect go beyond(above) the texture area.This explains why they were disappearing.
For a game I'm working on, I'd like to compare two sprites in SFML2, such as with an if() statement. For example, I could have a large 1280x1024 image with one gray pixel among all black pixels. I would then have 2 separate sprites, one is the gray pixel alone, and the other is the map. I would crop only the gray pixel from the map and compare the two, if true, do other things.
Do you see what I'm getting at here? Is this possible? If so, how?
Im with Alex in saying there are smarter ways to check sprites.
Compare the file names not, don't reference a single pixel within an image, because you have to load the entire image into memory to do that atm you are loading 1.3MBytes into memory just to check a single pixel?
Store all of your resources in a Resource Manager and reference them via a UID, if a resource has UID then use that resource.
Number 2 is preferable above all else, but there are many other ways
Edit: As per comments, you wouldn't "crop" out the pixel, you would just load image into memory and use the Image class to get the colour of a pixel at a location. The following would be an example
sf::Image* map = MapSprite->GetTexture()->CopyToImage()
if (map->GetPixel(666,666) == sf::Color::Black)
{
//Funky stuff here
}
NOTE: You mentioned SFML2 so this is from that set of Documentation, may be different for 1.6
Edit2: Its been a while since I've used SMFL so hopefully the code snippet will at least give you direction