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playcanvas

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Open-source WebGL/WebGPU 3D engine for the web

playcanvas.com

playcanvas/engine

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declare const _default: "\nstruct FaceCoords {\n uv: vec2f, // Original return value\n faceIndex: f32, // Was out parameter\n tileOffset: vec2f, // Was out parameter\n}\n\n// Converts unnormalized direction vector to a cubemap face index [0..5] and uv coordinates within the face in [0..1] range.\n// Additionally offset to a tile in atlas within 3x3 subdivision is provided\nfn getCubemapFaceCoordinates(dir: vec3f) -> FaceCoords {\n var faceIndex: f32;\n var tileOffset: vec2f;\n var uv: vec2f; // This is the face UV [0..1]\n let vAbs: vec3f = abs(dir);\n var ma: f32;\n\n if (vAbs.z >= vAbs.x && vAbs.z >= vAbs.y) { // front / back\n\n let is_neg_z = dir.z < 0.0;\n faceIndex = select(4.0, 5.0, is_neg_z);\n ma = 0.5 / vAbs.z;\n uv = vec2f(select(dir.x, -dir.x, is_neg_z), -dir.y);\n tileOffset = vec2f(2.0, select(0.0, 1.0, is_neg_z));\n\n } else if (vAbs.y >= vAbs.x) { // top index 2, bottom index 3\n\n let is_neg_y = dir.y < 0.0;\n faceIndex = select(2.0, 3.0, is_neg_y);\n ma = 0.5 / vAbs.y;\n uv = vec2f(dir.x, select(dir.z, -dir.z, is_neg_y));\n tileOffset = vec2f(1.0, select(0.0, 1.0, is_neg_y));\n\n } else { // left / right\n\n let is_neg_x = dir.x < 0.0;\n faceIndex = select(0.0, 1.0, is_neg_x);\n ma = 0.5 / vAbs.x;\n uv = vec2f(select(-dir.z, dir.z, is_neg_x), -dir.y);\n tileOffset = vec2f(0.0, select(0.0, 1.0, is_neg_x));\n }\n\n uv = uv * ma + 0.5;\n return FaceCoords(uv, faceIndex, tileOffset);\n}\n\n// converts unnormalized direction vector to a texture coordinate for a cubemap face stored within texture atlas described by the viewport\nfn getCubemapAtlasCoordinates(omniAtlasViewport: vec3f, shadowEdgePixels: f32, shadowTextureResolution: f32, dir: vec3f) -> vec2f {\n\n let faceData: FaceCoords = getCubemapFaceCoordinates(dir);\n var uv: vec2f = faceData.uv;\n let tileOffset: vec2f = faceData.tileOffset;\n\n // move uv coordinates inwards inside to compensate for larger fov when rendering shadow into atlas\n let atlasFaceSize: f32 = omniAtlasViewport.z;\n let tileSize: f32 = shadowTextureResolution * atlasFaceSize;\n var offset: f32 = shadowEdgePixels / tileSize;\n uv = uv * (1.0 - offset * 2.0) + offset;\n\n // scale uv coordinates to cube face area within the viewport\n uv = uv * atlasFaceSize;\n\n // offset into face of the atlas (3x3 grid)\n uv = uv + tileOffset * atlasFaceSize;\n\n // offset into the atlas viewport\n uv = uv + omniAtlasViewport.xy;\n\n return uv;\n}\n"; export default _default;