// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package image

import (
	"bytes"

	"android.googlesource.com/platform/tools/gpu/framework/binary"
	"android.googlesource.com/platform/tools/gpu/framework/binary/endian"
	"android.googlesource.com/platform/tools/gpu/framework/device"
)

type fmtDF32S8 struct{ binary.Generate }

func (f *fmtDF32S8) Key() interface{}             { return *f }
func (*fmtDF32S8) String() string                 { return "DF32S8" }
func (*fmtDF32S8) Size(w, h int) int              { return w * h * 5 }
func (*fmtDF32S8) Check(d []byte, w, h int) error { return checkSize(d, w, h, 40) }

// DF32S8 returns a format containing an 32-bit signed float point depth and 8-bit
// unsigned integer stencil value per pixel.
func DF32S8() *fmtDF32S8 { return &fmtDF32S8{} }

func init() {
	RegisterConverter(DF32S8(), RGBA(),
		func(src []byte, width, height int) ([]byte, error) {
			r := endian.Reader(bytes.NewBuffer(src), device.LittleEndian)
			dst, i := make([]byte, width*height*4), 0
			for y := 0; y < height; y++ {
				for x := 0; x < width; x++ {
					d := r.Float32()
					s := byte(r.Int8())
					dst[i+0] = uint8(d * float32(255))
					dst[i+1] = 0
					dst[i+2] = s
					dst[i+3] = 255
					i += 4
				}
			}
			return dst, nil
		})
}