diff options
Diffstat (limited to 'source/blender/gpu/shaders/compositor/compositor_realize_on_domain.glsl')
-rw-r--r-- | source/blender/gpu/shaders/compositor/compositor_realize_on_domain.glsl | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/source/blender/gpu/shaders/compositor/compositor_realize_on_domain.glsl b/source/blender/gpu/shaders/compositor/compositor_realize_on_domain.glsl new file mode 100644 index 00000000000..b2961d07219 --- /dev/null +++ b/source/blender/gpu/shaders/compositor/compositor_realize_on_domain.glsl @@ -0,0 +1,25 @@ +#pragma BLENDER_REQUIRE(gpu_shader_compositor_texture_utilities.glsl) + +void main() +{ + ivec2 texel = ivec2(gl_GlobalInvocationID.xy); + + /* First, transform the input image by transforming the domain coordinates with the inverse of + * input image's transformation. The inverse transformation is an affine matrix and thus the + * coordinates should be in homogeneous coordinates. */ + vec2 coordinates = (mat3(inverse_transformation) * vec3(texel, 1.0)).xy; + + /* Since an input image with an identity transformation is supposed to be centered in the domain, + * we subtract the offset between the lower left corners of the input image and the domain, which + * is half the difference between their sizes, because the difference in size is on both sides of + * the centered image. */ + ivec2 domain_size = imageSize(domain_img); + ivec2 input_size = texture_size(input_tx); + vec2 offset = (domain_size - input_size) / 2.0; + + /* Subtract the offset and divide by the input image size to get the relevant coordinates into + * the sampler's expected [0, 1] range. */ + vec2 normalized_coordinates = (coordinates - offset) / input_size; + + imageStore(domain_img, texel, texture(input_tx, normalized_coordinates)); +} |