I have a multiviewport OpenGL modeler application. It has three different viewports : perspective, front and top. Now I want to paint a label for each viewport and not succeeding in doing it.
What is the best way to print a label for each different perspective?
EDITED : The result
Here is the result of my attempt:
I don't understand why the perspective viewport label got scrambled like that. And, Actually I want to draw it in the upper left corner. How do I accomplished this, because I think it want 3D coordinate... is that right? Here is my code of drawing the label
glColor3f(1,0,0);
glDisable(GL_DEPTH_TEST);
glDepthMask(GL_FALSE);
glRasterPos2f(0,0);
glPushAttrib(GL_LIST_BIT); // Pushes The Display List Bits
glListBase(base - 32); // Sets The Base Character to 32
glCallLists(strlen("Perspective"), GL_UNSIGNED_BYTE, "Perspective"); // Draws The Display List Textstrlen(label)
glPopAttrib();
I use the code from here http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=13
thanks
For each viewport switch into a projection that allows you to supply "viewport space" coordinates, disable depth testing (glDisable(GL_DEPTH_TEST)) and depth writes (glDepthMask(GL_FALSE)) and draw the text using one of the methods used to draw text in OpenGL (texture mapped fonts, rendering the full text into a texture drawing that one, draw glyphs as actual geometry).
Along with #datenwolf's excellent answer, I'd add just one bit of advice: rather than drawing the label in the viewport, it's usually easier (and often looks better) to draw the label just outside the viewport. This avoids the label covering anything in the viewport, and makes it easy to get nice, cleanly anti-aliased text (which you can normally do in OpenGL as well, but it's more difficult).
If you decide you need to draw the text inside the viewport anyway, I'll add just one minor detail to what #datenwolf said: since you generally do want your text anti-aliased (even if the rest of the picture isn't) you generally want to draw the label after all the other geometry of the picture itself. If you haven't turned on anti-aliasing otherwise, you generally will want to turn it on for drawing the text.
Related
So I have an instanced scene that is supposed to be the child of a colour rect in my tree. I want to randomly generate the nodes, but I also want parts of the view to be cut off if the texture no longer is above the main section. I know you can render nodes below their parents, but I don't know if stopping part of them from rendering is physically possible.
In this image I want the bottom circle to remain the same, but the top circle to not show anything above the dark purple box
This is the node tree in the editor
Is there any way to do this directly, or am I gonna have to use a viewport of some variety?
I believe what you want is to set rect_clip_content to true on the ColorRect (or whatever Control). Making invisible any part of its children outside of it.
From Godot's documentation:
bool rect_clip_content
Enables whether rendering of CanvasItem based children should be clipped to this control's rectangle. If true, parts of a child which would be visibly outside of this control's rectangle will not be rendered.
If what you want is the opposite, perhaps you can use z_index to have something render on top, occluding the parts you don't want visible.
There is also a trick you can use with lights (including 2D lights):
Make a light that matches the area you want things to be visible.
Set a custom material that will be transparent by default, but visible on the light pass. The simpler way to do this is to set the light_mode of the material to "Light Only". You could also do it with a custom shader instead.
Making something disappear with light, in 2D, is impossible. In 3D, you can use flags_use_shadow_to_opacity. That is how you make a shadow catcher.
But, there is one more trick: you can use a mask. This should give you full control of when to show or hide things. So, if none of the above solutions works for you, use a mask. I have an explanation in a different answer. See also: How to crop sprite in a non-rectangular form?.
Mighty Mochi Games recently (2022-03-30) made a compilation of the different approaches in video form: Mask Methods Collection - Godot 3.x - 2D
.
Is it possible to have the vtkAxesActor small in a corner of the window?
Here is a image of what I currently got and what I would like to have. The colorful axes are the standard axesActor. But I would like the axes in a corner of the window and only there (bottom left in black). They shouldn't move around the window when the view is rotated. Only around their origin.
Is this possible? And if yes, how?
A possible solution is to put the vtkAxesActor into an orientation widget:
widget = vtk.vtkOrientationMarkerWidget()
widget.SetOrientationMarker(axisActor)
widget.SetInteractor(interactor)
widget.SetViewport(0, 0, size, size)
widget.InteractiveOff()
widget.EnabledOn()
The vtkAxesActor location is functional and it's location has a purpose. The anchor point of the AxesActor is the anchor point of the model. This provides context of where any transformations or translations would be calculated from.
Unfortunately the example of the axisActor in the corner you have proposed would only provide context of the orientation of the model and so not part of the standard options.
I am developing a game using Phaser where a user is rendered a triangular canvas. User can crop this canvas to any possible shape by drawing any crop pattern on the canvas. Besides this, i need to get this cropped canvas in suitable data format to be used as an image to render and also trace changes made on this canvas for undoing puspose.
Any help to get this through will be appreciated.
Thanks in advance.
Initial canvas
Canvas after crop
Cropped canvas used to create new canvas
So it's like folding a piece of paper and then cutting it so it looks like a snowflake? Interesting idea.
I think you could either use BitmapData to draw the initial cut out, then copy that bitmap 6 (or 12?) times and rotate and flip x-axis to construct the rest. Though maybe there will be seems, so like small lines, between the parts idk.
Another appproach would be to keep track of the initial cutlines like vectors. Then use math/trigonometry to calculate the result. No idea how to do this though, sorry.
I have an image of size 480x800 pixels and there is a icon on one corner which I need to place. What I want is that to ignore all touches on the transparent areas and detect only the area where the icon is.
I found a solution in SO to this problem but it just tells the code to be used. I need to know exactly where to put that code since I am a beginner and don't know much about cocos2d so I expect a step by step solution.
Cocos2d 2.0 - Ignoring touches to transparent areas of layers/sprites
Do not use glReadPixels because it affected by bugs in android drivers. You can translate CCTouch to CCPoint in image coordinates using convertTouchToNodeSpace, and read image pixel at given point.
Create CCImage from file that contains semi-transparent picture, and read one pixel at tap point; it should be {0,0,0,0} for transparent area.
Don't forget to check that tap is not outside picture, and create pixel index in CCImage::getData() array with formulae unsigned index = x * imageWidth + y.
I'm using Raphael to draw rectangles. Whoo-hoo!
Is there a way to right align contents of an SVG file?
Not just text, but shapes as well?
I can do the math and get the computed x value, but I'm looking for the lazy-simple solution.
Thank you.
There isn't. Unlike normal web pages where the window is resized and the content flows into it, when a Raphael paper is resized, there is no sort of flow, so aligning is irrelevant. Instead of setting align=right, you just set the right edge to be the same position you set the width of the paper to be. If you enlarge the paper, you can scale the contents with a single operation. Once you've set the position of the right edge, you've essentially set the align position. You don't need to re-set all edge values when the paper changes size, you just scale everything with one command. Hope that helps