Cleanup: moved IMB_transform to transform.cc.

Part of a refactoring to make IMB_transform more generic to reduce
unneeded branching.

1 files changed, 273 insertions, 0 deletions

diff --git a/source/blender/imbuf/intern/transform.cc b/source/blender/imbuf/intern/transform.cc
new file mode 100644
index 00000000000..6fd1a216313
--- /dev/null
+++ b/source/blender/imbuf/intern/transform.cc
@@ -0,0 +1,273 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup imbuf
+ */
+
+#include "BLI_math.h"
+#include "BLI_rect.h"
+
+#include "IMB_imbuf.h"
+#include "IMB_imbuf_types.h"
+
+namespace blender::imbuf::transform {
+
+/* -------------------------------------------------------------------- */
+/** \name Image transform
+ * \{ */
+
+static void pixel_from_buffer(
+    const struct ImBuf *ibuf, unsigned char **outI, float **outF, int x, int y)
+
+{
+  size_t offset = ((size_t)ibuf->x) * y * 4 + 4 * x;
+
+  if (ibuf->rect) {
+    *outI = (unsigned char *)ibuf->rect + offset;
+  }
+
+  if (ibuf->rect_float) {
+    *outF = ibuf->rect_float + offset;
+  }
+}
+
+struct TransformUserData {
+  const ImBuf *src;
+  ImBuf *dst;
+  float start_uv[2];
+  float add_x[2];
+  float add_y[2];
+  rctf src_crop;
+
+  void init_start_uv(const float transform_matrix[4][4])
+  {
+    float start_uv_v3[3];
+    float orig[3];
+    zero_v3(orig);
+    mul_v3_m4v3(start_uv_v3, transform_matrix, orig);
+    copy_v2_v2(start_uv, start_uv_v3);
+  }
+
+  void init_add_x(const float transform_matrix[4][4], const int width)
+  {
+    float add_x_v3[3];
+    float uv_max_x[3];
+    zero_v3(uv_max_x);
+    uv_max_x[0] = width;
+    uv_max_x[1] = 0.0f;
+    mul_v3_m4v3(add_x_v3, transform_matrix, uv_max_x);
+    sub_v2_v2(add_x_v3, start_uv);
+    mul_v2_fl(add_x_v3, 1.0f / width);
+    copy_v2_v2(add_x, add_x_v3);
+  }
+
+  void init_add_y(const float transform_matrix[4][4], const int height)
+  {
+    float add_y_v3[3];
+    float uv_max_y[3];
+    zero_v3(uv_max_y);
+    uv_max_y[0] = 0.0f;
+    uv_max_y[1] = height;
+    mul_v3_m4v3(add_y_v3, transform_matrix, uv_max_y);
+    sub_v2_v2(add_y_v3, start_uv);
+    mul_v2_fl(add_y_v3, 1.0f / height);
+    copy_v2_v2(add_y, add_y_v3);
+  }
+};
+
+BLI_INLINE void imb_transform_scanlines(const TransformUserData *user_data,
+                                        int scanline,
+                                        InterpolationColorFunction interpolation)
+{
+  const int width = user_data->dst->x;
+
+  float uv[2];
+  madd_v2_v2v2fl(uv, user_data->start_uv, user_data->add_y, scanline);
+
+  unsigned char *outI = nullptr;
+  float *outF = nullptr;
+  pixel_from_buffer(user_data->dst, &outI, &outF, 0, scanline);
+
+  for (int xi = 0; xi < width; xi++) {
+    interpolation(user_data->src, outI, outF, uv[0], uv[1]);
+    add_v2_v2(uv, user_data->add_x);
+    if (outI) {
+      outI += 4;
+    }
+    if (outF) {
+      outF += 4;
+    }
+  }
+}
+
+static void imb_transform_nearest_scanlines(void *custom_data, int scanline)
+{
+  const TransformUserData *user_data = static_cast<const TransformUserData *>(custom_data);
+  InterpolationColorFunction interpolation = nullptr;
+  if (user_data->dst->rect_float) {
+    interpolation = nearest_interpolation_color_fl;
+  }
+  else {
+    interpolation = nearest_interpolation_color_char;
+  }
+  imb_transform_scanlines(user_data, scanline, interpolation);
+}
+
+static void imb_transform_bilinear_scanlines(void *custom_data, int scanline)
+{
+  const TransformUserData *user_data = static_cast<const TransformUserData *>(custom_data);
+  InterpolationColorFunction interpolation = nullptr;
+  if (user_data->dst->rect_float) {
+    interpolation = bilinear_interpolation_color_fl;
+  }
+  else if (user_data->dst->rect) {
+    interpolation = bilinear_interpolation_color_char;
+  }
+  imb_transform_scanlines(user_data, scanline, interpolation);
+}
+
+BLI_INLINE void imb_transform_scanlines_with_crop(const TransformUserData *user_data,
+                                                  int scanline,
+                                                  InterpolationColorFunction interpolation)
+{
+  const int width = user_data->dst->x;
+
+  float uv[2];
+  madd_v2_v2v2fl(uv, user_data->start_uv, user_data->add_y, scanline);
+
+  unsigned char *outI = nullptr;
+  float *outF = nullptr;
+  pixel_from_buffer(user_data->dst, &outI, &outF, 0, scanline);
+
+  for (int xi = 0; xi < width; xi++) {
+    if (uv[0] >= user_data->src_crop.xmin && uv[0] < user_data->src_crop.xmax &&
+        uv[1] >= user_data->src_crop.ymin && uv[1] < user_data->src_crop.ymax) {
+      interpolation(user_data->src, outI, outF, uv[0], uv[1]);
+    }
+    add_v2_v2(uv, user_data->add_x);
+    if (outI) {
+      outI += 4;
+    }
+    if (outF) {
+      outF += 4;
+    }
+  }
+}
+
+static void imb_transform_nearest_scanlines_with_crop(void *custom_data, int scanline)
+{
+  const TransformUserData *user_data = static_cast<const TransformUserData *>(custom_data);
+  InterpolationColorFunction interpolation = nullptr;
+  if (user_data->dst->rect_float) {
+    interpolation = nearest_interpolation_color_fl;
+  }
+  else {
+    interpolation = nearest_interpolation_color_char;
+  }
+  imb_transform_scanlines_with_crop(user_data, scanline, interpolation);
+}
+
+static void imb_transform_bilinear_scanlines_with_crop(void *custom_data, int scanline)
+{
+  const TransformUserData *user_data = static_cast<const TransformUserData *>(custom_data);
+  InterpolationColorFunction interpolation = nullptr;
+  if (user_data->dst->rect_float) {
+    interpolation = bilinear_interpolation_color_fl;
+  }
+  else if (user_data->dst->rect) {
+    interpolation = bilinear_interpolation_color_char;
+  }
+  imb_transform_scanlines_with_crop(user_data, scanline, interpolation);
+}
+
+static void imb_transform_nearest_scanlines_with_repeat(void *custom_data, int scanline)
+{
+  const TransformUserData *user_data = static_cast<const TransformUserData *>(custom_data);
+  InterpolationColorFunction interpolation = nearest_interpolation_color_wrap;
+  imb_transform_scanlines(user_data, scanline, interpolation);
+}
+
+static ScanlineThreadFunc imb_transform_scanline_func(const eIMBInterpolationFilterMode filter,
+                                                      const eIMBTransformMode mode)
+{
+  ScanlineThreadFunc scanline_func = nullptr;
+  switch (mode) {
+    case IMB_TRANSFORM_MODE_REGULAR:
+      switch (filter) {
+        case IMB_FILTER_NEAREST:
+          scanline_func = imb_transform_nearest_scanlines;
+          break;
+        case IMB_FILTER_BILINEAR:
+          scanline_func = imb_transform_bilinear_scanlines;
+          break;
+      }
+      break;
+
+    case IMB_TRANSFORM_MODE_CROP_SRC:
+      switch (filter) {
+        case IMB_FILTER_NEAREST:
+          scanline_func = imb_transform_nearest_scanlines_with_crop;
+          break;
+        case IMB_FILTER_BILINEAR:
+          scanline_func = imb_transform_bilinear_scanlines_with_crop;
+          break;
+      }
+      break;
+
+    case IMB_TRANSFORM_MODE_WRAP_REPEAT:
+      BLI_assert_msg(filter == IMB_FILTER_NEAREST,
+                     "Repeat mode is only supported with nearest interpolation.");
+      scanline_func = imb_transform_nearest_scanlines_with_repeat;
+      break;
+  }
+  return scanline_func;
+}
+
+}  // namespace blender::imbuf::transform
+
+extern "C" {
+
+using namespace blender::imbuf::transform;
+
+void IMB_transform(const struct ImBuf *src,
+                   struct ImBuf *dst,
+                   const eIMBTransformMode mode,
+                   const eIMBInterpolationFilterMode filter,
+                   const float transform_matrix[4][4],
+                   const struct rctf *src_crop)
+{
+  BLI_assert_msg(mode != IMB_TRANSFORM_MODE_CROP_SRC || src_crop != nullptr,
+                 "No source crop rect given, but crop source is requested. Or source crop rect "
+                 "was given, but crop source was not requested.");
+  TransformUserData user_data;
+  user_data.src = src;
+  user_data.dst = dst;
+  if (mode == IMB_TRANSFORM_MODE_CROP_SRC) {
+    user_data.src_crop = *src_crop;
+  }
+  user_data.init_start_uv(transform_matrix);
+  user_data.init_add_x(transform_matrix, src->x);
+  user_data.init_add_y(transform_matrix, src->y);
+  ScanlineThreadFunc scanline_func = imb_transform_scanline_func(filter, mode);
+  IMB_processor_apply_threaded_scanlines(dst->y, scanline_func, &user_data);
+}
+}
+
+/** \} */