• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34

/**
 * Generic Mask Stack data structure
 * @memberof PIXI.utils
 * @function createIndicesForQuads
 * @param {number} size - Number of quads
 * @param {Uint16Array|Uint32Array} [outBuffer] - Buffer for output, length has to be `6 * size`
 * @returns {Uint16Array|Uint32Array} - Resulting index buffer
 */
export function createIndicesForQuads(size: number, outBuffer: Uint16Array | Uint32Array = null): Uint16Array | Uint32Array
{
    // the total number of indices in our array, there are 6 points per quad.
    const totalIndices = size * 6;

    outBuffer = outBuffer || new Uint16Array(totalIndices);

    if (outBuffer.length !== totalIndices)
    {
        throw new Error(`Out buffer length is incorrect, got ${outBuffer.length} and expected ${totalIndices}`);
    }

    // fill the indices with the quads to draw
    for (let i = 0, j = 0; i < totalIndices; i += 6, j += 4)
    {
        outBuffer[i + 0] = j + 0;
        outBuffer[i + 1] = j + 1;
        outBuffer[i + 2] = j + 2;
        outBuffer[i + 3] = j + 0;
        outBuffer[i + 4] = j + 2;
        outBuffer[i + 5] = j + 3;
    }

    return outBuffer;
}