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#pragma BLENDER_REQUIRE(gpu_shader_compositor_blur_common.glsl)
#pragma BLENDER_REQUIRE(gpu_shader_compositor_texture_utilities.glsl)
vec4 load_input(ivec2 texel)
{
vec4 color;
if (extend_bounds) {
/* If bounds are extended, then we treat the input as padded by a radius amount of pixels. So
* we load the input with an offset by the radius amount and fallback to a transparent color if
* it is out of bounds. Notice that we subtract 1 because the weights texture have an extra
* center weight, see the SymmetricSeparableBlurWeights for more information. */
int blur_size = texture_size(weights_tx) - 1;
color = texture_load(input_tx, texel - ivec2(blur_size, 0), vec4(0.0));
}
else {
color = texture_load(input_tx, texel);
}
if (gamma_correct_input) {
color = gamma_correct_blur_input(color);
}
return color;
}
void main()
{
ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
vec4 accumulated_color = vec4(0.0);
/* First, compute the contribution of the center pixel. */
vec4 center_color = load_input(texel);
accumulated_color += center_color * texture_load(weights_tx, 0).x;
/* Then, compute the contributions of the pixel to the right and left, noting that the
* weights texture only stores the weights for the positive half, but since the filter is
* symmetric, the same weight is used for the negative half and we add both of their
* contributions. */
for (int i = 1; i < texture_size(weights_tx); i++) {
float weight = texture_load(weights_tx, i).x;
accumulated_color += load_input(texel + ivec2(i, 0)) * weight;
accumulated_color += load_input(texel + ivec2(-i, 0)) * weight;
}
if (gamma_uncorrect_output) {
accumulated_color = gamma_uncorrect_blur_output(accumulated_color);
}
/* Write the color using the transposed texel. See the execute_separable_blur_horizontal_pass
* method for more information on the rational behind this. */
imageStore(output_img, texel.yx, accumulated_color);
}
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