/* WellspringCS - C# bindings for the Wellspring font rendering Library
 *
 * Copyright (c) 2022 Evan Hemsley
 *
 * This software is provided 'as-is', without any express or implied warranty.
 * In no event will the authors be held liable for any damages arising from
 * the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software in a
 * product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 *
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 *
 * 3. This notice may not be removed or altered from any source distribution.
 *
 * Evan "cosmonaut" Hemsley <evan@moonside.games>
 *
 */

using System;
using System.Runtime.InteropServices;

namespace WellspringCS
{
	public static class Wellspring
	{
		private const string nativeLibName = "Wellspring";

		// Version

		public const uint WELLSPRING_MAJOR_VERSION = 0;
		public const uint WELLSPRING_MINOR_VERSION = 1;
		public const uint WELLSPRING_PATCH_VERSION = 0;

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern uint Wellspring_LinkedVersion();

		[StructLayout(LayoutKind.Sequential)]
		public struct FontRange
		{
			uint FontSize;
			uint FirstCodepoint;
			uint NumChars;
			byte OversampleH;
			byte OversampleV;
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct Color
		{
			public byte R;
			public byte G;
			public byte B;
			public byte A;
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct Vertex
		{
			float X;
			float Y;
			float Z;
			float U;
			float V;
			byte R;
			byte G;
			byte B;
			byte A;
		}

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern IntPtr Wellspring_CreatePacker(
			IntPtr fontBytes,
			uint fontBytesLength,
			uint width,
			uint height,
			uint strideInBytes,
			uint padding
		);

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern uint Wellspring_PackFontRanges(
			IntPtr packer,
			IntPtr ranges, /* FontRange array */
			uint numRanges
		);

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern void Wellspring_GetPixels(
			IntPtr packer,
			IntPtr pData /* byte array */
		);

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern IntPtr Wellspring_CreateTextBatch();

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern void Wellspring_StartTextBatch(
			IntPtr packer
		);

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern byte Wellspring_Draw(
			IntPtr textBatch,
			IntPtr packer,
			float x,
			float y,
			float depth,
			in Color color,
			IntPtr strBytes, /* UTF-8 bytes */
			uint strLengthInBytes
		);

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern void Wellspring_GetBufferLengths(
			IntPtr textBatch,
			out uint vertexCount,
			out uint indexCount
		);

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern void Wellspring_GetBuffers(
			IntPtr textBatch,
			IntPtr vertexBuffer, /* Vertex array */
			IntPtr indexBuffer /* uint array */
		);

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern void Wellspring_DestroyTextBatch(
			IntPtr textBatch
		);

		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
		public static extern void Wellspring_DestroyPacker(
			IntPtr packer
		);
	}
}