// Copyright 2014 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING file in the root of the source

// tree. An additional intellectual property rights grant can be found

// in the file PATENTS. All contributing project authors may

// be found in the AUTHORS file in the root of the source tree.

// -----------------------------------------------------------------------------

//

// WebPPicture tools: copy, crop, rescaling and view.

//

// Author: Skal (pascal.massimino@gmail.com)

#include <assert.h>

#include <stdlib.h>

#include "src/dsp/dsp.h"

#include "src/enc/vp8i_enc.h"

#include "src/webp/encode.h"

#include "src/webp/types.h"

#if !defined(WEBP_REDUCE_SIZE)

#include "src/utils/rescaler_utils.h"

#include "src/utils/utils.h"

#endif  // !defined(WEBP_REDUCE_SIZE)

#define HALVE(x) (((x) + 1) >> 1)

// Grab the 'specs' (writer, *opaque, width, height...) from 'src' and copy them

// into 'dst'. Mark 'dst' as not owning any memory.

static void PictureGrabSpecs(const WebPPicture* const src,

                             WebPPicture* const dst) {

  assert(src != NULL && dst != NULL);

  *dst = *src;

  WebPPictureResetBuffers(dst);

}

//------------------------------------------------------------------------------

// Adjust top-left corner to chroma sample position.

static void SnapTopLeftPosition(const WebPPicture* const pic, int* const left,

                                int* const top) {

  if (!pic->use_argb) {

    *left &= ~1;

    *top &= ~1;

  }

}

// Adjust top-left corner and verify that the sub-rectangle is valid.

static int AdjustAndCheckRectangle(const WebPPicture* const pic,

                                   int* const left, int* const top, int width,

                                   int height) {

  SnapTopLeftPosition(pic, left, top);

  if ((*left) < 0 || (*top) < 0) return 0;

  if (width <= 0 || height <= 0) return 0;

  if ((*left) + width > pic->width) return 0;

  if ((*top) + height > pic->height) return 0;

  return 1;

}

#if !defined(WEBP_REDUCE_SIZE)

int WebPPictureCopy(const WebPPicture* src, WebPPicture* dst) {

  if (src == NULL || dst == NULL) return 0;

  if (src == dst) return 1;

  PictureGrabSpecs(src, dst);

  if (!WebPPictureAlloc(dst)) return 0;

  if (!src->use_argb) {

    WebPCopyPlane(src->y, src->y_stride, dst->y, dst->y_stride, dst->width,

                  dst->height);

    WebPCopyPlane(src->u, src->uv_stride, dst->u, dst->uv_stride,

                  HALVE(dst->width), HALVE(dst->height));

    WebPCopyPlane(src->v, src->uv_stride, dst->v, dst->uv_stride,

                  HALVE(dst->width), HALVE(dst->height));

    if (dst->a != NULL) {

      WebPCopyPlane(src->a, src->a_stride, dst->a, dst->a_stride, dst->width,

                    dst->height);

    }

  } else {

    WebPCopyPlane((const uint8_t*)src->argb, 4 * src->argb_stride,

                  (uint8_t*)dst->argb, 4 * dst->argb_stride, 4 * dst->width,

                  dst->height);

  }

  return 1;

}

#endif  // !defined(WEBP_REDUCE_SIZE)

int WebPPictureIsView(const WebPPicture* picture) {

  if (picture == NULL) return 0;

  if (picture->use_argb) {

    return (picture->memory_argb_ == NULL);

  }

  return (picture->memory_ == NULL);

}

int WebPPictureView(const WebPPicture* src, int left, int top, int width,

                    int height, WebPPicture* dst) {

  if (src == NULL || dst == NULL) return 0;

  // verify rectangle position.

  if (!AdjustAndCheckRectangle(src, &left, &top, width, height)) return 0;

  if (src != dst) {  // beware of aliasing! We don't want to leak 'memory_'.

    PictureGrabSpecs(src, dst);

  }

  dst->width = width;

  dst->height = height;

  if (!src->use_argb) {

    dst->y = src->y + top * src->y_stride + left;

    dst->u = src->u + (top >> 1) * src->uv_stride + (left >> 1);

    dst->v = src->v + (top >> 1) * src->uv_stride + (left >> 1);

    dst->y_stride = src->y_stride;

    dst->uv_stride = src->uv_stride;

    if (src->a != NULL) {

      dst->a = src->a + top * src->a_stride + left;

      dst->a_stride = src->a_stride;

    }

  } else {

    dst->argb = src->argb + top * src->argb_stride + left;

    dst->argb_stride = src->argb_stride;

  }

  return 1;

}

#if !defined(WEBP_REDUCE_SIZE)

//------------------------------------------------------------------------------

// Picture cropping

int WebPPictureCrop(WebPPicture* pic, int left, int top, int width,

                    int height) {

  WebPPicture tmp;

  if (pic == NULL) return 0;

  if (!AdjustAndCheckRectangle(pic, &left, &top, width, height)) return 0;

  PictureGrabSpecs(pic, &tmp);

  tmp.width = width;

  tmp.height = height;

  if (!WebPPictureAlloc(&tmp)) {

    return WebPEncodingSetError(pic, tmp.error_code);

  }

  if (!pic->use_argb) {

    const int y_offset = top * pic->y_stride + left;

    const int uv_offset = (top / 2) * pic->uv_stride + left / 2;

    WebPCopyPlane(pic->y + y_offset, pic->y_stride, tmp.y, tmp.y_stride, width,

                  height);

    WebPCopyPlane(pic->u + uv_offset, pic->uv_stride, tmp.u, tmp.uv_stride,

                  HALVE(width), HALVE(height));

    WebPCopyPlane(pic->v + uv_offset, pic->uv_stride, tmp.v, tmp.uv_stride,

                  HALVE(width), HALVE(height));

    if (tmp.a != NULL) {

      const int a_offset = top * pic->a_stride + left;

      WebPCopyPlane(pic->a + a_offset, pic->a_stride, tmp.a, tmp.a_stride,

                    width, height);

    }

  } else {

    const uint8_t* const src =

        (const uint8_t*)(pic->argb + top * pic->argb_stride + left);

    WebPCopyPlane(src, pic->argb_stride * 4, (uint8_t*)tmp.argb,

                  tmp.argb_stride * 4, width * 4, height);

  }

  WebPPictureFree(pic);

  *pic = tmp;

  return 1;

}

//------------------------------------------------------------------------------

// Simple picture rescaler

static int RescalePlane(const uint8_t* src, int src_width, int src_height,

                        int src_stride, uint8_t* dst, int dst_width,

                        int dst_height, int dst_stride, rescaler_t* const work,

                        int num_channels) {

  WebPRescaler rescaler;

  int y = 0;

  if (!WebPRescalerInit(&rescaler, src_width, src_height, dst, dst_width,

                        dst_height, dst_stride, num_channels, work)) {

    return 0;

  }

  while (y < src_height) {

    y += WebPRescalerImport(&rescaler, src_height - y, src + y * src_stride,

                            src_stride);

    WebPRescalerExport(&rescaler);

  }

  return 1;

}

static void AlphaMultiplyARGB(WebPPicture* const pic, int inverse) {

  assert(pic->argb != NULL);

  WebPMultARGBRows((uint8_t*)pic->argb, pic->argb_stride * sizeof(*pic->argb),

                   pic->width, pic->height, inverse);

}

static void AlphaMultiplyY(WebPPicture* const pic, int inverse) {

  if (pic->a != NULL) {

    WebPMultRows(pic->y, pic->y_stride, pic->a, pic->a_stride, pic->width,

                 pic->height, inverse);

  }

}

int WebPPictureRescale(WebPPicture* picture, int width, int height) {

  WebPPicture tmp;

  int prev_width, prev_height;

  rescaler_t* work;

  int status = VP8_ENC_OK;

  if (picture == NULL) return 0;

  prev_width = picture->width;

  prev_height = picture->height;

  if (!WebPRescalerGetScaledDimensions(prev_width, prev_height, &width,

                                       &height)) {

    return WebPEncodingSetError(picture, VP8_ENC_ERROR_BAD_DIMENSION);

  }

  PictureGrabSpecs(picture, &tmp);

  tmp.width = width;

  tmp.height = height;

  if (!WebPPictureAlloc(&tmp)) {

    return WebPEncodingSetError(picture, tmp.error_code);

  }

  if (!picture->use_argb) {

    work = (rescaler_t*)WebPSafeMalloc(2ULL * width, sizeof(*work));

    if (work == NULL) {

      status = VP8_ENC_ERROR_OUT_OF_MEMORY;

      goto Cleanup;

    }

    // If present, we need to rescale alpha first (for AlphaMultiplyY).

    if (picture->a != NULL) {

      WebPInitAlphaProcessing();

      if (!RescalePlane(picture->a, prev_width, prev_height, picture->a_stride,

                        tmp.a, width, height, tmp.a_stride, work, 1)) {

        status = VP8_ENC_ERROR_BAD_DIMENSION;

        goto Cleanup;

      }

    }

    // We take transparency into account on the luma plane only. That's not

    // totally exact blending, but still is a good approximation.

    AlphaMultiplyY(picture, 0);

    if (!RescalePlane(picture->y, prev_width, prev_height, picture->y_stride,

                      tmp.y, width, height, tmp.y_stride, work, 1) ||

        !RescalePlane(picture->u, HALVE(prev_width), HALVE(prev_height),

                      picture->uv_stride, tmp.u, HALVE(width), HALVE(height),

                      tmp.uv_stride, work, 1) ||

        !RescalePlane(picture->v, HALVE(prev_width), HALVE(prev_height),

                      picture->uv_stride, tmp.v, HALVE(width), HALVE(height),

                      tmp.uv_stride, work, 1)) {

      status = VP8_ENC_ERROR_BAD_DIMENSION;

      goto Cleanup;

    }

    AlphaMultiplyY(&tmp, 1);

  } else {

    work = (rescaler_t*)WebPSafeMalloc(2ULL * width * 4, sizeof(*work));

    if (work == NULL) {

      status = VP8_ENC_ERROR_BAD_DIMENSION;

      goto Cleanup;

    }

    // In order to correctly interpolate colors, we need to apply the alpha

    // weighting first (black-matting), scale the RGB values, and remove

    // the premultiplication afterward (while preserving the alpha channel).

    WebPInitAlphaProcessing();

    AlphaMultiplyARGB(picture, 0);

    if (!RescalePlane((const uint8_t*)picture->argb, prev_width, prev_height,

                      picture->argb_stride * 4, (uint8_t*)tmp.argb, width,

                      height, tmp.argb_stride * 4, work, 4)) {

      status = VP8_ENC_ERROR_BAD_DIMENSION;

      goto Cleanup;

    }

    AlphaMultiplyARGB(&tmp, 1);

  }

Cleanup:

  WebPSafeFree(work);

  if (status != VP8_ENC_OK) {

    WebPPictureFree(&tmp);

    return WebPEncodingSetError(picture, status);

  }

  WebPPictureFree(picture);

  *picture = tmp;

  return 1;

}

#else   // defined(WEBP_REDUCE_SIZE)

int WebPPictureCopy(const WebPPicture* src, WebPPicture* dst) {

  (void)src;

  (void)dst;

  return 0;

}

int WebPPictureCrop(WebPPicture* pic, int left, int top, int width,

                    int height) {

  (void)pic;

  (void)left;

  (void)top;

  (void)width;

  (void)height;

  return 0;

}

int WebPPictureRescale(WebPPicture* pic, int width, int height) {

  (void)pic;

  (void)width;

  (void)height;

  return 0;

}

#endif  // !defined(WEBP_REDUCE_SIZE)