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Diffstat (limited to 'config/picom/shaders/cross.glsl')
| -rw-r--r-- | config/picom/shaders/cross.glsl | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/config/picom/shaders/cross.glsl b/config/picom/shaders/cross.glsl new file mode 100644 index 0000000..2241508 --- /dev/null +++ b/config/picom/shaders/cross.glsl @@ -0,0 +1,335 @@ +#version 430 +#define PI 3.14159265 + +// These shaders work by using a pinhole camera and raycasting +// The window 3d objects will always be (somewhat) centered at (0, 0, 0) +struct pinhole_camera +{ + float focal_offset; // Distance along the Z axis between the camera + // center and the focal point. Use negative values + // so the image doesn't flip + // This kinda works like FOV in games + + // Transformations + // Use these to modify the coordinate system of the camera plane + vec3 rotations; // Rotations in radians around each axis + // The camera plane rotates around + // its center point, not the origin + + vec3 translations; // Translations in pixels along each axis + + vec3 deformations; // Deforms the camera. Higher values on each axis + // means the window will be squashed in that axis + + // ---------------------------------------------------------------// + + // "Aftervalues" + // These will be set later with setup_camera(), leave them as 0 + vec3 base_x; + vec3 base_y; + vec3 base_z; + vec3 center_point; + vec3 focal_point; +}; + +in vec2 texcoord; // texture coordinate of the fragment + +uniform sampler2D tex; // texture of the window + + +uniform float time; // Time in miliseconds. + +float time_cyclic = mod(time/10000,2); // Like time, but in seconds and resets to + // 0 when it hits 2. Useful for using it in + // periodic functions like cos and sine +// Time variables can be used to change transformations over time + + +ivec2 window_size = textureSize(tex, 0); // Size of the window + +float window_diagonal = length(window_size); // Diagonal of the window +// Try to keep focal offset and translations proportional to window_size components +// or window_diagonal as you see fit + +pinhole_camera camera = +pinhole_camera(-window_size.y/2, // Focal offset + vec3(0,0,0), // Rotations + vec3(0,0,0), // Translations + vec3(1,1,1), // Deformations + // Leave the rest as 0 + vec3(0), + vec3(0), + vec3(0), + vec3(0), + vec3(0)); + +// Here are some presets you can use + +// Moves the camera up and down +pinhole_camera bobbing = +pinhole_camera(-window_size.y/2, + vec3(0,0,0), + vec3(0,cos(time_cyclic*PI)*window_size.y/16,-window_size.y/4), + vec3(1,1,1), + vec3(0), + vec3(0), + vec3(0), + vec3(0), + vec3(0)); + +// Rotates camera around the origin +// Makes the window rotate around the Y axis from the camera's POV +// (if the window is centered) +pinhole_camera rotate_around_origin = +pinhole_camera(-window_diagonal, + vec3(0,-time_cyclic*PI-PI/2,0), + vec3(cos(time_cyclic*PI)*window_diagonal, + 0, + sin(time_cyclic*PI)*window_diagonal), + vec3(1,1,1), + vec3(0), + vec3(0), + vec3(0), + vec3(0), + vec3(0)); + +// Rotate camera around its center +pinhole_camera rotate_around_itself = +pinhole_camera(-window_diagonal, + vec3(0,-time_cyclic*PI-PI/2,0), + vec3(0,0,-window_diagonal), + vec3(1,1,1), + vec3(0), + vec3(0), + vec3(0), + vec3(0), + vec3(0)); + +// Here you can select the preset to use +pinhole_camera window_cam = rotate_around_origin; + + + +ivec2 window_center = ivec2(window_size.x/2, window_size.y/2); + +// Default window post-processing: +// 1) invert color +// 2) opacity / transparency +// 3) max-brightness clamping +// 4) rounded corners +vec4 default_post_processing(vec4 c); + +// Sets up a camera by applying transformations and +// calculating xyz vector basis +pinhole_camera setup_camera(pinhole_camera camera) +{ + // Apply translations + camera.center_point += camera.translations; + + // Apply rotations + // We initialize our vector basis as normalized vectors + // in each axis * our deformations vector + camera.base_x = vec3(camera.deformations.x, 0, 0); + camera.base_y = vec3(0, camera.deformations.y, 0); + camera.base_z = vec3(0, 0, camera.deformations.z); + + + // Then we rotate them around following our rotations vector: + // First save these values to avoid redundancy + float cosx = cos(camera.rotations.x); + float cosy = cos(camera.rotations.y); + float cosz = cos(camera.rotations.z); + float sinx = sin(camera.rotations.x); + float siny = sin(camera.rotations.y); + float sinz = sin(camera.rotations.z); + + // Declare a buffer vector we will use to apply multiple changes at once + vec3 tmp = vec3(0); + + // Rotations for base_x: + tmp = camera.base_x; + // X axis: + tmp.y = camera.base_x.y * cosx - camera.base_x.z * sinx; + tmp.z = camera.base_x.y * sinx + camera.base_x.z * cosx; + camera.base_x = tmp; + // Y axis: + tmp.x = camera.base_x.x * cosy + camera.base_x.z * siny; + tmp.z = -camera.base_x.x * siny + camera.base_x.z * cosy; + camera.base_x = tmp; + // Z axis: + tmp.x = camera.base_x.x * cosz - camera.base_x.y * sinz; + tmp.y = camera.base_x.x * sinz + camera.base_x.y * cosz; + camera.base_x = tmp; + + // Rotations for base_y: + tmp = camera.base_y; + // X axis: + tmp.y = camera.base_y.y * cosx - camera.base_y.z * sinx; + tmp.z = camera.base_y.y * sinx + camera.base_y.z * cosx; + camera.base_y = tmp; + // Y axis: + tmp.x = camera.base_y.x * cosy + camera.base_y.z * siny; + tmp.z = -camera.base_y.x * siny + camera.base_y.z * cosy; + camera.base_y = tmp; + // Z axis: + tmp.x = camera.base_y.x * cosz - camera.base_y.y * sinz; + tmp.y = camera.base_y.x * sinz + camera.base_y.y * cosz; + camera.base_y = tmp; + + // Rotations for base_z: + tmp = camera.base_z; + // X axis: + tmp.y = camera.base_z.y * cosx - camera.base_z.z * sinx; + tmp.z = camera.base_z.y * sinx + camera.base_z.z * cosx; + camera.base_z = tmp; + // Y axis: + tmp.x = camera.base_z.x * cosy + camera.base_z.z * siny; + tmp.z = -camera.base_z.x * siny + camera.base_z.z * cosy; + camera.base_z = tmp; + // Z axis: + tmp.x = camera.base_z.x * cosz - camera.base_z.y * sinz; + tmp.y = camera.base_z.x * sinz + camera.base_z.y * cosz; + camera.base_z = tmp; + + // Now that we have our transformed 3d orthonormal base + // we can calculate our focal point + camera.focal_point = camera.center_point + camera.base_z * camera.focal_offset; + + // Return our set up camera + return camera; +} + +// Gets a pixel from the end of a ray projected to an axis +vec4 get_pixel_from_projection(float t, int face, pinhole_camera camera, vec3 focal_vector) +{ + // If the point we end up in is behind our camera, don't "render" it + if (t < 1) + { + return vec4(0); + } + + // Then we multiply our focal vector by t and add our focal point to it + // to end up in a point inside the window plane + vec3 intersection = focal_vector * t + camera.focal_point; + + + // Save a the necessary coordinates and add back offset + vec2 cam_coords; + switch (face) + { + case 0: + cam_coords = intersection.xy + window_center; + break; + case 1: + cam_coords = intersection.zy + window_center; + break; + } + + // If pixel is outside of our window region + // return a completely transparent color + if (cam_coords.x >=window_size.x-1 || + cam_coords.y >=window_size.y-1 || + cam_coords.x <=0 || cam_coords.y <=0) + { + return vec4(0); + } + + // Fetch the pixel + vec4 pixel = texelFetch(tex, ivec2(cam_coords), 0); + return pixel; +} + +// Combines colors using alpha +// Got this from https://stackoverflow.com/questions/64701745/how-to-blend-colours-with-transparency +// Not sure how it works honestly lol +vec4 alpha_composite(vec4 color1, vec4 color2) +{ + + float ar = color1.w + color2.w - (color1.w * color2.w); + float asr = color2.w / ar; + float a1 = 1 - asr; + float a2 = asr * (1 - color1.w); + float ab = asr * color1.w; + vec4 outcolor; + outcolor.xyz = color1.xyz * a1 + color2.xyz * a2 + color2.xyz * ab; + outcolor.w = ar; + return outcolor; + +} + +// Gets a pixel through the camera using coords as coordinates in +// the camera plane +vec4 get_pixel_through_camera(vec2 coords, pinhole_camera camera) +{ + // Offset coords + coords -= window_center; + + // Find the pixel 3d position using the camera vector basis + vec3 pixel_3dposition = camera.center_point + + coords.x * camera.base_x + + coords.y * camera.base_y; + + // Get the vector going from the focal point to the pixel in 3d sapace + vec3 focal_vector = pixel_3dposition - camera.focal_point; + + // We need 2 planes, one for each axis of the cross, they all follow the plane EQ + // ax + by + cz + d + float a[] = {0,1}; + float b[] = {0,0}; + float c[] = {1,0}; + float d[] = {0,0}; + // Then there's a line going from our focal point to each of the planes + // which we can describe as: + // x(t) = focal_point.x + focal_vector.x * t + // y(t) = focal_point.y + focal_vector.y * t + // z(t) = focal_point.z + focal_vector.z * t + // We substitute x, y and z with x(t), y(t) and z(t) in the plane EQ + // Solving for t we get: + vec2 t[2]; // we use a vec2 to also store the plane that was hit + for (int i = 0; i < 2; i++) + { + t[i].x = (d[i] + - a[i]*camera.focal_point.x + - b[i]*camera.focal_point.y + - c[i]*camera.focal_point.z) + / (a[i]*focal_vector.x + + b[i]*focal_vector.y + + c[i]*focal_vector.z); + t[i].y = i; + } + + // Bubble sort to know which intersections happen first + for (int i = 0; i < t.length(); i++) + { + for (int j = 0; j < t.length(); j++) + { + if (t [j].x > t[j+1].x) + { + vec2 tmp = t[j]; + t[j] = t[j+1]; + t[j+1] = tmp; + } + } + } + + // Then we go through each one of the intersections in order + // and mix pixels together using alpha + vec4 blended_pixels = vec4(0); + for (int i = 0; i < 2; i++) + { + // We get the pixel through projection + vec4 projection_pixel = get_pixel_from_projection(t[i].x, + int(t[i].y), + camera, + focal_vector); + // Blend the pixel using alpha + blended_pixels = alpha_composite(projection_pixel, blended_pixels); + } + return blended_pixels; +} + +// Main function +vec4 window_shader() { + pinhole_camera transformed_cam = setup_camera(window_cam); + return(get_pixel_through_camera(texcoord, transformed_cam)); +} |