228 lines
9.5 KiB
JavaScript
228 lines
9.5 KiB
JavaScript
//This file is automatically rebuilt by the Cesium build process.
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export default "// These octree flags must be in sync with GpuOctreeFlag in VoxelTraversal.js\n\
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#define OCTREE_FLAG_INTERNAL 0\n\
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#define OCTREE_FLAG_LEAF 1\n\
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#define OCTREE_FLAG_PACKED_LEAF_FROM_PARENT 2\n\
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\n\
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#define OCTREE_MAX_LEVELS 32 // Harcoded value because GLSL doesn't like variable length loops\n\
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\n\
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uniform sampler2D u_octreeInternalNodeTexture;\n\
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uniform vec2 u_octreeInternalNodeTexelSizeUv;\n\
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uniform int u_octreeInternalNodeTilesPerRow;\n\
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#if (SAMPLE_COUNT > 1)\n\
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uniform sampler2D u_octreeLeafNodeTexture;\n\
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uniform vec2 u_octreeLeafNodeTexelSizeUv;\n\
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uniform int u_octreeLeafNodeTilesPerRow;\n\
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#endif\n\
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\n\
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struct OctreeNodeData {\n\
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int data;\n\
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int flag;\n\
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};\n\
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\n\
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struct TraversalData {\n\
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ivec4 octreeCoords;\n\
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int parentOctreeIndex;\n\
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};\n\
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\n\
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struct SampleData {\n\
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int megatextureIndex;\n\
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ivec4 tileCoords;\n\
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vec3 tileUv;\n\
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#if (SAMPLE_COUNT > 1)\n\
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float weight;\n\
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#endif\n\
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};\n\
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\n\
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// Integer mod: For WebGL1 only\n\
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int intMod(in int a, in int b) {\n\
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return a - (b * (a / b));\n\
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}\n\
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int normU8_toInt(in float value) {\n\
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return int(value * 255.0);\n\
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}\n\
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int normU8x2_toInt(in vec2 value) {\n\
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return int(value.x * 255.0) + 256 * int(value.y * 255.0);\n\
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}\n\
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float normU8x2_toFloat(in vec2 value) {\n\
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return float(normU8x2_toInt(value)) / 65535.0;\n\
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}\n\
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\n\
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OctreeNodeData getOctreeNodeData(in vec2 octreeUv) {\n\
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vec4 texData = texture(u_octreeInternalNodeTexture, octreeUv);\n\
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\n\
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OctreeNodeData data;\n\
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data.data = normU8x2_toInt(texData.xy);\n\
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data.flag = normU8x2_toInt(texData.zw);\n\
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return data;\n\
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}\n\
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\n\
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OctreeNodeData getOctreeChildData(in int parentOctreeIndex, in ivec3 childCoord) {\n\
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int childIndex = childCoord.z * 4 + childCoord.y * 2 + childCoord.x;\n\
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int octreeCoordX = intMod(parentOctreeIndex, u_octreeInternalNodeTilesPerRow) * 9 + 1 + childIndex;\n\
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int octreeCoordY = parentOctreeIndex / u_octreeInternalNodeTilesPerRow;\n\
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vec2 octreeUv = u_octreeInternalNodeTexelSizeUv * vec2(float(octreeCoordX) + 0.5, float(octreeCoordY) + 0.5);\n\
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return getOctreeNodeData(octreeUv);\n\
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}\n\
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\n\
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int getOctreeParentIndex(in int octreeIndex) {\n\
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int octreeCoordX = intMod(octreeIndex, u_octreeInternalNodeTilesPerRow) * 9;\n\
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int octreeCoordY = octreeIndex / u_octreeInternalNodeTilesPerRow;\n\
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vec2 octreeUv = u_octreeInternalNodeTexelSizeUv * vec2(float(octreeCoordX) + 0.5, float(octreeCoordY) + 0.5);\n\
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vec4 parentData = texture(u_octreeInternalNodeTexture, octreeUv);\n\
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int parentOctreeIndex = normU8x2_toInt(parentData.xy);\n\
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return parentOctreeIndex;\n\
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}\n\
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\n\
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/**\n\
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* Convert a position in the uv-space of the tileset bounding shape\n\
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* into the uv-space of a tile within the tileset\n\
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*/\n\
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vec3 getTileUv(in vec3 shapePosition, in ivec4 octreeCoords) {\n\
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// PERFORMANCE_IDEA: use bit-shifting (only in WebGL2)\n\
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float dimAtLevel = exp2(float(octreeCoords.w));\n\
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return shapePosition * dimAtLevel - vec3(octreeCoords.xyz);\n\
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}\n\
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\n\
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vec3 getClampedTileUv(in vec3 shapePosition, in ivec4 octreeCoords) {\n\
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vec3 tileUv = getTileUv(shapePosition, octreeCoords);\n\
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return clamp(tileUv, vec3(0.0), vec3(1.0));\n\
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}\n\
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\n\
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void getOctreeLeafSampleData(in OctreeNodeData data, in ivec4 octreeCoords, out SampleData sampleData) {\n\
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sampleData.megatextureIndex = data.data;\n\
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sampleData.tileCoords = (data.flag == OCTREE_FLAG_PACKED_LEAF_FROM_PARENT)\n\
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? ivec4(octreeCoords.xyz / 2, octreeCoords.w - 1)\n\
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: octreeCoords;\n\
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}\n\
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\n\
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#if (SAMPLE_COUNT > 1)\n\
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void getOctreeLeafSampleDatas(in OctreeNodeData data, in ivec4 octreeCoords, out SampleData sampleDatas[SAMPLE_COUNT]) {\n\
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int leafIndex = data.data;\n\
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int leafNodeTexelCount = 2;\n\
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// Adding 0.5 moves to the center of the texel\n\
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float leafCoordXStart = float(intMod(leafIndex, u_octreeLeafNodeTilesPerRow) * leafNodeTexelCount) + 0.5;\n\
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float leafCoordY = float(leafIndex / u_octreeLeafNodeTilesPerRow) + 0.5;\n\
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\n\
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// Get an interpolation weight and a flag to determine whether to read the parent texture\n\
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vec2 leafUv0 = u_octreeLeafNodeTexelSizeUv * vec2(leafCoordXStart + 0.0, leafCoordY);\n\
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vec4 leafData0 = texture(u_octreeLeafNodeTexture, leafUv0);\n\
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float lerp = normU8x2_toFloat(leafData0.xy);\n\
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sampleDatas[0].weight = 1.0 - lerp;\n\
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sampleDatas[1].weight = lerp;\n\
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// TODO: this looks wrong? Should be comparing to OCTREE_FLAG_PACKED_LEAF_FROM_PARENT\n\
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sampleDatas[0].tileCoords = (normU8_toInt(leafData0.z) == 1)\n\
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? ivec4(octreeCoords.xyz / 2, octreeCoords.w - 1)\n\
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: octreeCoords;\n\
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sampleDatas[1].tileCoords = (normU8_toInt(leafData0.w) == 1)\n\
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? ivec4(octreeCoords.xyz / 2, octreeCoords.w - 1)\n\
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: octreeCoords;\n\
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\n\
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// Get megatexture indices for both samples\n\
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vec2 leafUv1 = u_octreeLeafNodeTexelSizeUv * vec2(leafCoordXStart + 1.0, leafCoordY);\n\
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vec4 leafData1 = texture(u_octreeLeafNodeTexture, leafUv1);\n\
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sampleDatas[0].megatextureIndex = normU8x2_toInt(leafData1.xy);\n\
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sampleDatas[1].megatextureIndex = normU8x2_toInt(leafData1.zw);\n\
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}\n\
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#endif\n\
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\n\
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OctreeNodeData traverseOctreeDownwards(in vec3 shapePosition, inout TraversalData traversalData) {\n\
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float sizeAtLevel = exp2(-1.0 * float(traversalData.octreeCoords.w));\n\
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vec3 start = vec3(traversalData.octreeCoords.xyz) * sizeAtLevel;\n\
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vec3 end = start + vec3(sizeAtLevel);\n\
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OctreeNodeData childData;\n\
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\n\
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for (int i = 0; i < OCTREE_MAX_LEVELS; ++i) {\n\
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// Find out which octree child contains the position\n\
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// 0 if before center, 1 if after\n\
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vec3 center = 0.5 * (start + end);\n\
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vec3 childCoord = step(center, shapePosition);\n\
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\n\
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// Get octree coords for the next level down\n\
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ivec4 octreeCoords = traversalData.octreeCoords;\n\
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traversalData.octreeCoords = ivec4(octreeCoords.xyz * 2 + ivec3(childCoord), octreeCoords.w + 1);\n\
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\n\
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childData = getOctreeChildData(traversalData.parentOctreeIndex, ivec3(childCoord));\n\
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\n\
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if (childData.flag != OCTREE_FLAG_INTERNAL) {\n\
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// leaf tile - stop traversing\n\
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break;\n\
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}\n\
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\n\
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// interior tile - keep going deeper\n\
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start = mix(start, center, childCoord);\n\
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end = mix(center, end, childCoord);\n\
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traversalData.parentOctreeIndex = childData.data;\n\
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}\n\
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\n\
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return childData;\n\
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}\n\
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\n\
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/**\n\
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* Transform a given position to an octree tile coordinate and a position within that tile,\n\
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* and find the corresponding megatexture index and texture coordinates\n\
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*/\n\
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void traverseOctreeFromBeginning(in vec3 shapePosition, out TraversalData traversalData, out SampleData sampleDatas[SAMPLE_COUNT]) {\n\
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traversalData.octreeCoords = ivec4(0);\n\
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traversalData.parentOctreeIndex = 0;\n\
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\n\
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OctreeNodeData nodeData = getOctreeNodeData(vec2(0.0));\n\
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if (nodeData.flag != OCTREE_FLAG_LEAF) {\n\
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nodeData = traverseOctreeDownwards(shapePosition, traversalData);\n\
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}\n\
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\n\
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#if (SAMPLE_COUNT == 1)\n\
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getOctreeLeafSampleData(nodeData, traversalData.octreeCoords, sampleDatas[0]);\n\
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sampleDatas[0].tileUv = getClampedTileUv(shapePosition, sampleDatas[0].tileCoords);\n\
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#else\n\
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getOctreeLeafSampleDatas(nodeData, traversalData.octreeCoords, sampleDatas);\n\
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sampleDatas[0].tileUv = getClampedTileUv(shapePosition, sampleDatas[0].tileCoords);\n\
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sampleDatas[1].tileUv = getClampedTileUv(shapePosition, sampleDatas[1].tileCoords);\n\
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#endif\n\
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}\n\
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\n\
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bool inRange(in vec3 v, in vec3 minVal, in vec3 maxVal) {\n\
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return clamp(v, minVal, maxVal) == v;\n\
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}\n\
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\n\
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bool insideTile(in vec3 shapePosition, in ivec4 octreeCoords) {\n\
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vec3 tileUv = getTileUv(shapePosition, octreeCoords);\n\
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bool inside = inRange(tileUv, vec3(0.0), vec3(1.0));\n\
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// Assume (!) the position is always inside the root tile.\n\
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return inside || octreeCoords.w == 0;\n\
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}\n\
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\n\
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void traverseOctreeFromExisting(in vec3 shapePosition, inout TraversalData traversalData, inout SampleData sampleDatas[SAMPLE_COUNT]) {\n\
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if (insideTile(shapePosition, traversalData.octreeCoords)) {\n\
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for (int i = 0; i < SAMPLE_COUNT; i++) {\n\
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sampleDatas[0].tileUv = getClampedTileUv(shapePosition, sampleDatas[0].tileCoords);\n\
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}\n\
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return;\n\
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}\n\
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\n\
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// Go up tree until we find a parent tile containing shapePosition\n\
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for (int i = 0; i < OCTREE_MAX_LEVELS; ++i) {\n\
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traversalData.octreeCoords.xyz /= 2;\n\
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traversalData.octreeCoords.w -= 1;\n\
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\n\
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if (insideTile(shapePosition, traversalData.octreeCoords)) {\n\
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break;\n\
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}\n\
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\n\
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traversalData.parentOctreeIndex = getOctreeParentIndex(traversalData.parentOctreeIndex);\n\
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}\n\
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\n\
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// Go down tree\n\
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OctreeNodeData nodeData = traverseOctreeDownwards(shapePosition, traversalData);\n\
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\n\
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#if (SAMPLE_COUNT == 1)\n\
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getOctreeLeafSampleData(nodeData, traversalData.octreeCoords, sampleDatas[0]);\n\
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sampleDatas[0].tileUv = getClampedTileUv(shapePosition, sampleDatas[0].tileCoords);\n\
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#else\n\
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getOctreeLeafSampleDatas(nodeData, traversalData.octreeCoords, sampleDatas);\n\
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sampleDatas[0].tileUv = getClampedTileUv(shapePosition, sampleDatas[0].tileCoords);\n\
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sampleDatas[1].tileUv = getClampedTileUv(shapePosition, sampleDatas[1].tileCoords);\n\
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#endif\n\
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}\n\
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";
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