How does sampler2DArrayShadow in glsl works

Question

I am not able understand how to use sampler2DAprrayShadows and how it works. Got some part of it that we need to use depth texture values (GL_DEPTH_COMPONENT) to get the compare result with ref depth. But then how to use the return float value to get the texel.

Got reference from : http://www.khronos.org/opengles/sdk/docs/manglsl/xhtml/texture.xml

I have written a small code to test it as below: My fragment shader as:

in highp vec2 texcoord;
in highp vec4 basecolor;
out highp vec4 myFragColor;

uniform highp sampler2DArrayShadow basetexture;

void main(void)
{
    highp vec3 coords = (vec3(texcoord, 0.0) + vec3(1.0, 1.0, 1.0)) / 2.0;
    highp float depth = texture(basetexture, vec4(coords.x, coords.y, coords.z, -0.5));
    myFragColor = vec4(depth * basecolor);

}

Created 3D texture (texdata), and binding it as :

glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_COMPARE_MODE,  GL_COMPARE_REF_TO_TEXTURE);
glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_DEPTH_COMPONENT16, TEX_SIZE, TEX_SIZE, TEX_SIZE, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_SHORT, texdata);

Your question has been answered on the OpenGL forum http://www.opengl.org/discussion_boards/showthread.php/180780-How-does-sampler2DArrayShadow-in-glsl-works — wip, Apr 02 '13 at 08:56

score 1 · Answer 1 · edited Apr 26 '18 at 10:41

1

maybe this could help you: depth cubemap make tutorial

And to be frank, you're supposed to make a frame buffer object which binds a 2D depth texture instead of a Cubemap one. If you want to use sampler: sampler2DArrayShadow, then you just need to overload the glsl function texture, which is texture( Sampler2DArrayShadow gSampler, Vec4 P, [float bias]) .P.z is the number of the 2D tex, and P.w is the reference depth value. The default bias is 0, you can ignore it if don't need one.

edited Apr 26 '18 at 10:41

lushl9301

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1
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answered Apr 26 '18 at 08:49

Jacques Pacino

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Please write here the solution instead of including a link that could be broken in the future. Thanks! – Ignacio Ara Apr 26 '18 at 09:02
@IgnacioAra That's a SO link and the linked post is unlikely to get deleted (only moderators could do that, and they won't). – Filnor Apr 26 '18 at 09:17
This should be a comment, not an answer. If it is a duplicate question, [vote to close](http://stackoverflow.com/help/privileges/close-questions) as such and/or leave a comment once you [earn](http://meta.stackoverflow.com/q/146472) enough [reputation](http://stackoverflow.com/help/whats-reputation). If not, tailor the answer to this specific question. – Filnor Apr 26 '18 at 09:17

How does sampler2DArrayShadow in glsl works

1 Answers1