Simon Schneegans
57 lines
2.2 KiB
GLSL
57 lines
2.2 KiB
GLSL
// Inject some common shader snippets. It is only possible to include glsl files from the
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// "common" directory. Also, the files in the "common" directory are not allowed to
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// include any further files.
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#include "common/uniforms.glsl"
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#include "common/noise.glsl"
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#include "common/compositing.glsl"
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// See assets/README.md for how this texture was created.
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uniform sampler2D uClawTexture;
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uniform vec4 uFlashColor;
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uniform vec2 uSeed;
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uniform float uClawSize;
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uniform float uNumClaws;
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uniform float uWarpIntensity;
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const float FLASH_INTENSITY = 0.1;
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const float MAX_SPAWN_TIME =
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0.6; // Scratches will only start in the first half of the animation.
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const float FF_TIME = 0.6; // Relative time for the final fade to transparency.
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// This method generates a grid of randomly rotated, slightly shifted and scaled
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// UV squares. It returns the texture coords of the UV square at the given actor
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// coordinates. If these do not fall into one of the UV grids, the coordinates of
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// the closest UV grid will be clamped and returned.
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vec2 getClawUV(vec2 texCoords, float gridScale, vec2 seed) {
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// Shift coordinates by a random offset and make sure the have a 1:1 aspect ratio.
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vec2 coords = texCoords + hash22(seed);
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coords *= uSize.x < uSize.y ? vec2(1.0, 1.0 * uSize.y / uSize.x)
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: vec2(1.0 * uSize.x / uSize.y, 1.0);
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// Apply global scale.
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coords *= gridScale;
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// Get grid cell coordinates in [0..1].
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vec2 cellUV = mod(coords, vec2(1));
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// This is unique for each cell.
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vec2 cellID = coords - cellUV + vec2(362.456);
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// Add random rotation, scale and offset to each grid cell.
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float scale = mix(0.8, 1.0, hash12(cellID * seed * 134.451));
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float offsetX = mix(0.0, 1.0 - scale, hash12(cellID * seed * 54.4129));
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float offsetY = mix(0.0, 1.0 - scale, hash12(cellID * seed * 25.3089));
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float rotation = mix(0.0, 2.0 * 3.141, hash12(cellID * seed * 2.99837));
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cellUV -= vec2(offsetX, offsetY);
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cellUV /= scale;
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cellUV -= 0.5;
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cellUV = vec2(cellUV.x * cos(rotation) - cellUV.y * sin(rotation),
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cellUV.x * sin(rotation) + cellUV.y * cos(rotation));
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cellUV += 0.5;
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// Clamp resulting coordinates.
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return clamp(cellUV, vec2(0), vec2(1));
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} |