How can I pass an array of floats to the fragment shader using textures?

Posted by James on Game Development See other posts from Game Development or by James
Published on 2012-12-08T15:46:44Z Indexed on 2012/12/08 17:21 UTC
Read the original article Hit count: 307

Filed under:

opengl

|

shaders

I want to map out a 2D array of depth elements for the fragment shader to use to check depth against to create shadows. I want to be able to copy a float array into the GPU, but using large uniform arrays causes segfaults in openGL so that is not an option. I tried texturing but the best i got was to use GL_DEPTH_COMPONENT

glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, 512, 512, 0, GL_DEPTH_COMPONENT, GL_FLOAT, smap);

Which doesn't work because that stores depth components (0.0 - 1.0) which I don't want because I have no idea how to calculate them using the depth value produced by the light sources MVP matrix multiplied by the coordinate of each vertex.

Is there any way to store and access large 2D arrays of floats in openGL?

© Game Development or respective owner

Related posts about opengl

Unity completely broken after upgrade to 12.10?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am facing a very frustrating issue with my computer right now. I successfully upgraded to Ubuntu 12.10 this afternoon, but after the upgrade, the graphical user interface seems completely broken. To be more specific, I can not get the Unity bar to appear on the right. I have tried many things,… >>> More
OpenGL or OpenGL ES

as seen on Game Development - Search for 'Game Development'
What should I learn? OpenGL 4.1 or OpenGL ES 2.0? I will be developing desktop applications using Qt but I may start developing mobile applications in a few months, too. I don't know anything about 3D, 3D math, etc and I'd rather spend 100 bucks in a good book than 1 week digging websites and going… >>> More
OpenGL ES 2/3 vs OpenGL 3 (and 4)

as seen on Game Development - Search for 'Game Development'
I have migrated my code from OpenGL ES 2/3 to OpenGL 3 (I added bunch of defines and abstract classes to encapsulate both versions, so I have both in one project and compile only one or another). All I need to change was context initialization and glClearDepth. I dont have any errors. This was kind… >>> More
OpenGL extension vs OpenGL core

as seen on Programmers - Search for 'Programmers'
I was doubting: I'm writing a cross-platform engine OpenGL C++, I figured out windows forces the developers to access OpenGL features above 1.1 through extensions. Now the thing is, on Linux, I know that I can directly access functions if the version supports it through glext.h and opengl version… >>> More
LWJGL - Eclipse error [on hold]

as seen on Game Development - Search for 'Game Development'
When I try to run my lwjgl project, an error pops . Here is the log file: # A fatal error has been detected by the Java Runtime Environment: # EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d8fcc0a, pid=5612, tid=900 # JRE version: 6.0_16-b01 Java VM: Java HotSpot(TM) Client VM (14.2-b01 mixed… >>> More

Related posts about shaders

Implementing algorithms via compute shaders vs. pipeline shaders

as seen on Game Development - Search for 'Game Development'
With the availability of compute shaders for both DirectX and OpenGL it's now possible to implement many algorithms without going through the rasterization pipeline and instead use general purpose computing on the GPU to solve the problem. For some algorithms this seems to become the intuitive canonical… >>> More
How do multipass shaders work in OpenGL?

as seen on Game Development - Search for 'Game Development'
In Direct3D, multipass shaders are simple to use because you can literally define passes within a program. In OpenGL, it seems a bit more complex because it is possible to give a shader program as many vertex, geometry, and fragment shaders as you want. A popular example of a multipass shader is… >>> More
Differences in cg shader code for OpenGL vs. for DirectX?

as seen on Game Development - Search for 'Game Development'
I have been trying to use an existing library that automatically generates shaders (Hydrax plugin for Ogre3D). These shaders are used to render water and somewhat involved, but are not extremely complicated. However there seems to be some differences in how the cg shaders are handled by OpenGL and… >>> More
WPF Parent Window shading using Pixel Shaders

as seen on Code Project - Search for 'Code Project'
This article discusses using Pixel Shaders to shade the main window when a dialog is showing. >>> More
Unity3D draw call optimization : static batching VS manually draw mesh with MaterialPropertyBlock

as seen on Game Development - Search for 'Game Development'
I've read Unity3D draw call batching documentation. I understood it, and I want to use it (or something similar) in order to optimize my application. My situation is the following: I'm drawing hundreds of 3d buildings. Each building can be represented using a Mesh (or a SubMesh for each building… >>> More