glsl

As the title says, I can't do vector_array[foo] (assuming foo is in-range and integer) in webgl vertex shaders, correct? Are textures the best alternative, or is there a workaround or some better way to mimick a lookup table? http://www.khronos.org/registry/webgl/specs/latest/#DYNAMIC_INDEXING_OF_ARRAYS "WebGL only allows dynamic indexing with constant expressions, loop indices or a combination. The only exception is for uniform access in vertex shaders, which can be indexed using any expression." Did you try it? If it didn't work, there are a couple options. If you have a small number of

I have implemented a depth peeling algorithm using a GLSL spinlock (inspired by this ). In the following visualization, notice how overall the depth peeling algorithm functions correctly (first layer top left, second layer top right, third layer bottom left, fourth layer bottom right). The four depth layers are stored into a single RGBA texture. Unfortunately, the spinlock sometimes fails to prevent errors--you can see little white speckles, particularly in the fourth layer. There's also one on the wing of the spaceship in the second layer. These speckles vary each frame. In my GLSL spinlock,

i am currently doing so rendering in OpenGL 4.3 using UBOs to store all my constant data on the GPU. (Stuff like material descriptions, matrices, ...). It works however the small size of UBO (64kB on my implementation) forces me to switch buffers numerous times slowing rendering, i am looking for similar a way to store a few MB. After a little research i saw that SSBO allow exactly that but also have unwanted 'features' : they can be written from the shader and might be slower to read. Is there a better solution than SSBO for supplying big chunks of data to shaders ? I feel like i am missing

In theory, mesa 10.0.1 should support OpenGL 3.3 but currently I'm only getting 3.0 support. glxinfo gives some confusing results... [pdel@architect build]$ glxinfo | grep -i opengl OpenGL vendor string: Intel Open Source Technology Center OpenGL renderer string: Mesa DRI Intel(R) Ivybridge Mobile OpenGL core profile version string: 3.3 (Core Profile) Mesa 10.0.1 OpenGL core profile shading language version string: 3.30 OpenGL core profile context flags: (none) OpenGL core profile profile mask: core profile OpenGL core profile extensions: OpenGL version string: 3.0 Mesa 10.0.1 OpenGL shading

I am using OpenGL3.2 Core Profile on OSX. And I want to do instanced drawing (glDrawArraysInstanced), where I pass a matrix for each instance. My vertex shader builds just fine: #version 150 in mediump vec4 position; in mediump mat4 trf; in lowp vec4 rgb; out lowp vec4 colour; uniform highp mat4 modelcamviewprojmat; void main() { mediump vec4 tpos = trf * position; gl_Position = modelcamviewprojmat * tpos; colour = rgb; } The binding of 'trf' went fine: glBindAttribLocation(program, ATTRIB_TRF, "trf" ); But how can I pass in my data? glVertexAttribPointer can not pass values larger than 4

I am making a program that uses two different shaders for different different primitives. My question is, if I bind a program, send it uniform variables, then use another shader program and come back to the first one, will the passed uniform values remain? Here is some pseudocode: glUseProgram(shader1); glUniform(shader1,...); //stuff for(elements in a list) { if(element.type = 1) { glUseProgram(shader2); element.draw(); } else { glUseProgram(shader1); //Here, do the uniforms from above remain, if shader2 was bound before? element.draw(); } } Yes, uniforms are specific to a program, and will