Is it possible to move part of the texture into another texture part without performance hits?
I looked into opengl SDK, but haven't found anything that could do something like this.
glCopyPixels lets you to copy from one framebuffer area into another (I never used it).
glBlitFramebuffer lets you to copy pixels between framebuffers
glCopyTexImage lets you to copy pixels from framebuffer into a texture
Using these function you can accomplish the task by, for example, the following actions:
create FBO, attach texture-1 into the first color channel
bind fbo, set viewport to contain the source area
call glCopyTexSubImage into the texture-2 to get the contents
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
.
I am new to phaser and I am having hard time to find this, probably cause I don't know how to call it. I know you can very simply load image through url, give it name and then use it in a sprite.
But what if I want to load image, which contains lots of different tiled images and use each of them separately? I'd like to somehow define, that for example rectangle at (x,y), using (width, height) is an image, that I can then use in spritesheet. I found tilemap definition files, but they are usually one file per image.
I found createStaticLayer, where you can pass 2-dimensional array of numbers, where number is order of tile and that works pretty much similarly to how I'd like to use it, but it is for background only and I still can't extract single "image" for single sprite.
How do I do that? How is that called? I am sure it exists, I am just missing it :)
I would like to implement red lines moving oh H/V rulers similar to what I see in windows paint brush (8.1) indicating current mouse position. See the example (red line at 560):
What would be the best way to do it. Direct2D Animation? layers? any other simple trick? The thing here is of cause doing it efficiently without repainting the whole area on mouse move.
I currently using MFC/direct2d so I paint myself the area with field and rulers inside the view, so I have full control on graphics here.
There are many ways to attack this problem. The simplest is to rely on your OnPaint function to paint the line in a location based on a member variable. In your OnMouseMove handler, call InvalidateRect on the current location of the line based on the saved variable, update the variable, and call InvalidateRect a second time for the new line position.
The BeginPaint call that is generated in the CPaintDC constructor will set a clipping region based on the invalidation rectangles you provided. Even if your OnPaint tries to paint the entire window, only those parts that have been invalidated will be redrawn. If this is too inefficient, you can cache the ruler in a bitmap and use GetClipBox to determine which part of the bitmap to blit to the screen.
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've been stumbling over this for a while and was wondering if anyone has run into this problem before.
The application I'm working on is divided into multiple data plots and a single timeline at the bottom of the screen. Each plot (which is actually multiple textures layered on top of each other) as well as the timeline is rendered to a separate texture. The timeline texture is rendered first, followed by each of the plot textures from the top of the screen to the bottom. I am using DXUT and DirectX9 (March 2009).
After adding time text to the timeline texture, I noticed that the text was repeated in the title bar of every data plot. Here's a screencap of a portion of the display, it shows just a single plot, but the text repeats on every plot opened:
It seems like it is tied directly to the DrawText being called in the timeline's render function. I do use relative coordinates as the rect being passed to DrawText, but since I've already set the render target to the desired texture it should only affect the current texture. Not every texture rendered afterward.
Has anyone ever run into any problems similar to this using D3DXFont?
EDIT: After some more experimentation, it looks like it has something to do with the Z buffer. By adding D3DCLEAR_ZBUFFER to the clear on each texture surface, the duplicate text is gone. While the problem seems bypassed for now, I'm still curious as to why the Z buffer for a completely separate texture was being written during my DrawText call.
The Z Buffer state is persistent.
For example,
SetDepthStencilSurface(X)
SetRenderTarget(A)
Draw()
SetRenderTarget(B)
Draw()
Both Draw calls will use the same depth buffer.
The DrawText is not changing the depth buffer that you have set. It assumes you meant to do what you did.