Terrain4J_Experimental_branch/resources/EngineResources/shaders/packed_scene_vertex.glsl

#version 450

layout(location = 0) out vec4 outPos;
layout(location = 1) out vec3 outNormal;
layout(location = 2) out vec3 outTangent;
layout(location = 3) out vec3 outBitangent;
layout(location = 4) out vec2 outTextCoords;
layout(location = 5) out mat4 viewMatrix;
layout(location = 9) out flat uint outMaterialID;

layout(set = 0, binding = 0) uniform ProjUniform { mat4 matrix; } projUniform;
layout(set = 1, binding = 0) uniform ViewUniform { mat4 matrix; } viewUniform;

layout(set = 4, binding = 0) readonly buffer FaceBuffer {
    uint faces[];
};

layout(push_constant) uniform pc {
    vec4 ModelOffset;
    vec4 Padding0;
    vec4 Padding1;
    vec4 Padding2;
} push_constants;

const uint TRI_TO_CORNER[6] = uint[6](0u, 1u, 2u, 0u, 2u, 3u);

const vec3 NORMALS[8] = vec3[8](
        vec3( 0.0,  1.0,  0.0), // Face 0 (+Y)
        vec3( 0.0, -1.0,  0.0), // Face 1 (-Y)
        vec3( 1.0,  0.0,  0.0), // Face 2 (+X)
        vec3(-1.0,  0.0,  0.0), // Face 3 (-X)
        vec3( 0.0,  0.0,  1.0), // Face 4 (+Z)
        vec3( 0.0,  0.0, -1.0), // Face 5 (-Z)
        vec3(-0.7071, 0.0, 0.7071), // Face 6
        vec3( 0.7071, 0.0, 0.7071)  // Face 7
);

const vec3 TANGENTS[8] = vec3[8](
        vec3( 1.0,  0.0,  0.0), // Face 0
        vec3( 1.0,  0.0,  0.0), // Face 1
        vec3( 0.0,  0.0, -1.0), // Face 2
        vec3( 0.0,  0.0,  1.0), // Face 3
        vec3( 1.0,  0.0,  0.0), // Face 4
        vec3(-1.0,  0.0,  0.0), // Face 5
        vec3( 0.7071, 0.0, 0.7071), // Face 6
        vec3( 0.7071, 0.0,-0.7071)  // Face 7
);

const vec3 BITANGENTS[8] = vec3[8](
        vec3( 0.0,  0.0,  1.0), // Face 0
        vec3( 0.0,  0.0, -1.0), // Face 1
        vec3( 0.0,  1.0,  0.0), // Face 2
        vec3( 0.0,  1.0,  0.0), // Face 3
        vec3( 0.0,  1.0,  0.0), // Face 4
        vec3( 0.0,  1.0,  0.0), // Face 5
        vec3( 0.0,  1.0,  0.0), // Face 6
        vec3( 0.0,  1.0,  0.0)  // Face 7
);

const vec2 CORNER_UVS[5][4] = vec2[5][4](
        vec2[4](vec2(0.5, 0.0), vec2(0.5, 0.5), vec2(1.0, 0.5), vec2(1.0, 0.0)),
        vec2[4](vec2(0.0, 0.5), vec2(0.0, 1.0), vec2(0.5, 1.0), vec2(0.5, 0.5)),
        vec2[4](vec2(0.5, 0.0), vec2(0.5, 0.5), vec2(1.0, 0.5), vec2(1.0, 0.0)),
        vec2[4](vec2(0.5, 0.0), vec2(0.5, 0.5), vec2(1.0, 0.5), vec2(1.0, 0.0)),
        vec2[4](vec2(1.0, 1.0), vec2(1.0, 0.5), vec2(0.5, 0.5), vec2(0.5, 1.0))
);
const vec2 CORNER_UVS_GRASS_BLOCK[8][4] = vec2[8][4](
        vec2[4](vec2(0.0, 0.0), vec2(0.0, 1.0), vec2(1.0, 1.0), vec2(1.0, 0.0)),
        vec2[4](vec2(0.0, 0.0), vec2(0.0, 1.0), vec2(1.0, 1.0), vec2(1.0, 0.0)),
        vec2[4](vec2(1.0, 1.0), vec2(1.0, 0.0),vec2(0.0, 0.0), vec2(0.0, 1.0)),
        vec2[4]( vec2(0.0, 1.0),vec2(1.0, 1.0), vec2(1.0, 0.0),vec2(0.0, 0.0)),
        vec2[4]( vec2(0.0, 1.0),vec2(1.0, 1.0), vec2(1.0, 0.0),vec2(0.0, 0.0)),
        vec2[4](vec2(1.0, 1.0), vec2(1.0, 0.0),vec2(0.0, 0.0), vec2(0.0, 1.0)),
        vec2[4](vec2(1.0, 1.0), vec2(1.0, 0.0), vec2(0.0, 0.0), vec2(0.0, 1.0)),
        vec2[4](vec2(1.0, 1.0), vec2(1.0, 0.0), vec2(0.0, 0.0), vec2(0.0, 1.0))

);

const vec3 FACE_CORNERS[8][4] = vec3[8][4](
        vec3[4](vec3(0.0, 1.0, 0.0), vec3(0.0, 1.0, 1.0), vec3(1.0, 1.0, 1.0), vec3(1.0, 1.0, 0.0)), // Face 0 (+Y)
        vec3[4](vec3(0.0, 0.0, 0.0), vec3(1.0, 0.0, 0.0), vec3(1.0, 0.0, 1.0), vec3(0.0, 0.0, 1.0)), // Face 1 (-Y)
        vec3[4](vec3(1.0, 0.0, 0.0), vec3(1.0, 1.0, 0.0), vec3(1.0, 1.0, 1.0), vec3(1.0, 0.0, 1.0)), // Face 2 (+X)
        vec3[4](vec3(0.0, 0.0, 0.0), vec3(0.0, 0.0, 1.0), vec3(0.0, 1.0, 1.0), vec3(0.0, 1.0, 0.0)), // Face 3 (-X)
        vec3[4](vec3(0.0, 0.0, 1.0), vec3(1.0, 0.0, 1.0), vec3(1.0, 1.0, 1.0), vec3(0.0, 1.0, 1.0)), // Face 4 (+Z)
        vec3[4](vec3(0.0, 0.0, 0.0), vec3(0.0, 1.0, 0.0), vec3(1.0, 1.0, 0.0), vec3(1.0, 0.0, 0.0)), // Face 5 (-Z)
        vec3[4](vec3(0.0, 0.0, 0.0), vec3(0.0, 1.0, 0.0), vec3(1.0, 1.0, 1.0), vec3(1.0, 0.0, 1.0)), // Face 6 (cross model pane 1)
        vec3[4](vec3(0.0, 0.0, 1.0), vec3(0.0, 1.0, 1.0), vec3(1.0, 1.0, 0.0), vec3(1.0, 0.0, 0.0))  // Face 7 (cross model pane 2)
);

void main() {
    viewMatrix = viewUniform.matrix;

    uint faceRecordIndex = uint(gl_VertexIndex) / 6u;
    uint triangleVertex = (uint(gl_VertexIndex))% 6u;
    uint cornerIndex = TRI_TO_CORNER[triangleVertex];

    uint packedFace = faces[faceRecordIndex];

    uint voxelX =  packedFace & 0xFu;
    uint voxelY = (packedFace >> 4u)  & 0xFu;
    uint voxelZ = (packedFace >> 8u) & 0xFu;
    uint faceId = (packedFace >> 12u) & 0x7u;
    uint matId  = (packedFace >> 15u) & 0x7FFu;
    uint texIdxX = (packedFace >> 26u) & 0x7u;
    uint texIdxY = (packedFace >> 29u) & 0x7u;

    vec2 texID = vec2((texIdxX)/4.0,(texIdxY)/4.0);
    vec2 scalar = vec2(1.0/4.0,1.0/4.0);

    faceId = min(faceId, 7u);

    vec3 localPos = vec3(voxelX, voxelY, voxelZ) + FACE_CORNERS[faceId][cornerIndex];
    vec3 Offset = vec3(0,0,0);
    vec3 worldPos = localPos + Offset + push_constants.ModelOffset.xyz * 16.0;

    vec4 worldPosVec4 = vec4(worldPos, 1.0);

    gl_Position = projUniform.matrix * viewUniform.matrix * worldPosVec4;
    outPos = worldPosVec4;
    outNormal = NORMALS[faceId];
    outTangent = TANGENTS[faceId];
    outBitangent = BITANGENTS[faceId];
    vec2 atlasSize = vec2(64, 64);
    vec2 texel = 0.5 / atlasSize;
    vec2 tileMin = vec2(texIdxX, texIdxY) * scalar + texel;
    vec2 tileMax = vec2(texIdxX + 1u, texIdxY + 1u) * scalar - texel;
    outTextCoords = mix(tileMin, tileMax, CORNER_UVS_GRASS_BLOCK[faceId][cornerIndex]);
    outMaterialID = matId;
}