Implement helper functionalities for computing image size with ES3 settings.

This will be used in ReadPixels, Tex{Sub}Image* in followup CLs.

BUG=429053,563714
TEST=gpu_unittests
R=piman@chromium.org

Review URL: https://codereview.chromium.org/1508953002

Cr-Commit-Position: refs/heads/master@{#364095}

3 files changed, 276 insertions, 42 deletions

diff --git a/gpu/command_buffer/common/gles2_cmd_utils.cc b/gpu/command_buffer/common/gles2_cmd_utils.cc
index 8b547fa..93f1980 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils.cc
@@ -509,67 +509,153 @@ uint32 GLES2Util::ComputeImageGroupSize(int format, int type) {
   return  bytes_per_element * elements_per_group;
 }
 
-bool GLES2Util::ComputeImagePaddedRowSize(
-        int width, int format, int type, int unpack_alignment,
-        uint32* padded_row_size) {
-  DCHECK(unpack_alignment == 1 || unpack_alignment == 2 ||
-         unpack_alignment == 4 || unpack_alignment == 8);
-  uint32 bytes_per_group = ComputeImageGroupSize(format, type);
+bool GLES2Util::ComputeImageRowSizeHelper(
+    int width, uint32 bytes_per_group, int alignment,
+    uint32* rt_unpadded_row_size, uint32* rt_padded_row_size) {
+  DCHECK(alignment == 1 || alignment == 2 ||
+         alignment == 4 || alignment == 8);
   uint32 unpadded_row_size;
   if (!SafeMultiplyUint32(width, bytes_per_group, &unpadded_row_size)) {
     return false;
   }
   uint32 temp;
-  if (!SafeAddUint32(unpadded_row_size, unpack_alignment - 1, &temp)) {
-      return false;
+  if (!SafeAddUint32(unpadded_row_size, alignment - 1, &temp)) {
+    return false;
   }
-  *padded_row_size = (temp / unpack_alignment) * unpack_alignment;
+  uint32 padded_row_size = (temp / alignment) * alignment;
+  if (rt_unpadded_row_size)
+    *rt_unpadded_row_size = unpadded_row_size;
+  if (rt_padded_row_size)
+    *rt_padded_row_size = padded_row_size;
   return true;
 }
 
+bool GLES2Util::ComputeImagePaddedRowSize(
+    int width, int format, int type, int alignment, uint32* padded_row_size) {
+  uint32 bytes_per_group = ComputeImageGroupSize(format, type);
+  return ComputeImageRowSizeHelper(
+      width, bytes_per_group, alignment, nullptr, padded_row_size);
+}
+
 // Returns the amount of data glTexImage*D or glTexSubImage*D will access.
 bool GLES2Util::ComputeImageDataSizes(
     int width, int height, int depth, int format, int type,
-    int unpack_alignment, uint32* size, uint32* ret_unpadded_row_size,
-    uint32* ret_padded_row_size) {
-  DCHECK(unpack_alignment == 1 || unpack_alignment == 2 ||
-         unpack_alignment == 4 || unpack_alignment == 8);
+    int alignment, uint32* size, uint32* opt_unpadded_row_size,
+    uint32* opt_padded_row_size) {
+  DCHECK(width >= 0 && height >= 0 && height >=0);
+  if (width == 0 || height == 0 || depth == 0) {
+    *size = 0;
+    return true;
+  }
+
   uint32 bytes_per_group = ComputeImageGroupSize(format, type);
-  uint32 row_size;
-  if (!SafeMultiplyUint32(width, bytes_per_group, &row_size)) {
+
+  uint32 unpadded_row_size;
+  uint32 padded_row_size;
+  if (!ComputeImageRowSizeHelper(width, bytes_per_group, alignment,
+                                 &unpadded_row_size, &padded_row_size)) {
     return false;
   }
   uint32 num_of_rows;
   if (!SafeMultiplyUint32(height, depth, &num_of_rows)) {
     return false;
   }
-  if (num_of_rows > 1) {
-    uint32 temp;
-    if (!SafeAddUint32(row_size, unpack_alignment - 1, &temp)) {
+  DCHECK(num_of_rows > 0);
+  uint32 size_of_all_but_last_row;
+  if (!SafeMultiplyUint32((num_of_rows - 1), padded_row_size,
+                          &size_of_all_but_last_row)) {
+    return false;
+  }
+  if (!SafeAddUint32(size_of_all_but_last_row, unpadded_row_size, size)) {
+    return false;
+  }
+  if (opt_padded_row_size) {
+    *opt_padded_row_size = padded_row_size;
+  }
+  if (opt_unpadded_row_size) {
+    *opt_unpadded_row_size = unpadded_row_size;
+  }
+
+  return true;
+}
+
+bool GLES2Util::ComputeImageDataSizesES3(
+    int width, int height, int depth, int format, int type,
+    const PixelStoreParams& params,
+    uint32_t* size, uint32_t* opt_unpadded_row_size,
+    uint32_t* opt_padded_row_size, uint32_t* opt_skip_size) {
+  DCHECK(width >= 0 && height >= 0 && height >=0);
+  if (width == 0 || height == 0 || depth == 0) {
+    *size = 0;
+    return true;
+  }
+
+  uint32 bytes_per_group = ComputeImageGroupSize(format, type);
+
+  uint32 unpadded_row_size;
+  uint32 padded_row_size;
+  if (!ComputeImageRowSizeHelper(width, bytes_per_group, params.alignment,
+                                 &unpadded_row_size, &padded_row_size)) {
+    return false;
+  }
+  if (params.row_length > 0 &&
+      !ComputeImageRowSizeHelper(params.row_length, bytes_per_group,
+                                 params.alignment, nullptr, &padded_row_size)) {
+    // Here we re-compute the padded_row_size, but the unpadded_row_size
+    // isn't affected. That is, the last row isn't affected by ROW_LENGTH.
+    return false;
+  }
+
+  int image_height = params.image_height > 0 ? params.image_height : height;
+  uint32 num_of_rows;
+  if (!SafeMultiplyUint32(image_height, depth - 1, &num_of_rows) ||
+      !SafeAddUint32(num_of_rows, height, &num_of_rows)) {
+    return false;
+  }
+  DCHECK(num_of_rows > 0);
+  uint32 size_of_all_but_last_row;
+  if (!SafeMultiplyUint32((num_of_rows - 1), padded_row_size,
+                          &size_of_all_but_last_row)) {
+    return false;
+  }
+  if (!SafeAddUint32(size_of_all_but_last_row, unpadded_row_size, size)) {
+    return false;
+  }
+
+  uint32 skip_size = 0;
+  if (params.skip_images > 0) {
+    uint32 image_size;
+    if (!SafeMultiplyUint32(image_height, padded_row_size, &image_size))
       return false;
-    }
-    uint32 padded_row_size = (temp / unpack_alignment) * unpack_alignment;
-    uint32 size_of_all_but_last_row;
-    if (!SafeMultiplyUint32((num_of_rows - 1), padded_row_size,
-                            &size_of_all_but_last_row)) {
+    if (!SafeMultiplyUint32(image_size, params.skip_images, &skip_size))
       return false;
-    }
-    if (!SafeAddUint32(size_of_all_but_last_row, row_size, size)) {
+  }
+  if (params.skip_rows > 0) {
+    uint32 temp;
+    if (!SafeMultiplyUint32(padded_row_size, params.skip_rows, &temp))
+      return false;
+    if (!SafeAddUint32(skip_size, temp, &skip_size))
       return false;
-    }
-    if (ret_padded_row_size) {
-      *ret_padded_row_size = padded_row_size;
-    }
-  } else {
-    *size = row_size;
-    if (ret_padded_row_size) {
-      *ret_padded_row_size = row_size;
-    }
   }
-  if (ret_unpadded_row_size) {
-    *ret_unpadded_row_size = row_size;
+  if (params.skip_pixels > 0) {
+    uint32 temp;
+    if (!SafeMultiplyUint32(bytes_per_group, params.skip_pixels, &temp))
+      return false;
+    if (!SafeAddUint32(skip_size, temp, &skip_size))
+      return false;
   }
+  uint32 total_size;
+  if (!SafeAddUint32(*size, skip_size, &total_size))
+    return false;
 
+  if (opt_padded_row_size) {
+    *opt_padded_row_size = padded_row_size;
+  }
+  if (opt_unpadded_row_size) {
+    *opt_unpadded_row_size = unpadded_row_size;
+  }
+  if (opt_skip_size)
+    *opt_skip_size = skip_size;
   return true;
 }
 
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.h b/gpu/command_buffer/common/gles2_cmd_utils.h
index 3aa0299..e3b82b8 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.h
+++ b/gpu/command_buffer/common/gles2_cmd_utils.h
@@ -52,6 +52,24 @@ inline bool SafeAddInt32(int32_t a, int32_t b, int32_t* dst) {
   return checked.IsValid();
 }
 
+struct GLES2_UTILS_EXPORT PixelStoreParams {
+  PixelStoreParams()
+      : alignment(4),
+        row_length(0),
+        image_height(0),
+        skip_pixels(0),
+        skip_rows(0),
+        skip_images(0) {
+  }
+
+  int32_t alignment;
+  int32_t row_length;
+  int32_t image_height;
+  int32_t skip_pixels;
+  int32_t skip_rows;
+  int32_t skip_images;
+};
+
 // Utilties for GLES2 support.
 class GLES2_UTILS_EXPORT GLES2Util {
  public:
@@ -105,17 +123,26 @@ class GLES2_UTILS_EXPORT GLES2Util {
 
   // Computes the size of an image row including alignment padding
   static bool ComputeImagePaddedRowSize(
-      int width, int format, int type, int unpack_alignment,
+      int width, int format, int type, int alignment,
       uint32_t* padded_row_size);
 
   // Computes the size of image data for TexImage2D and TexSubImage2D.
-  // Optionally the unpadded and padded row sizes can be returned. If height < 2
-  // then the padded_row_size will be the same as the unpadded_row_size since
-  // padding is not necessary.
+  // Optionally the unpadded and padded row sizes can be returned.
   static bool ComputeImageDataSizes(
       int width, int height, int depth, int format, int type,
-      int unpack_alignment, uint32_t* size, uint32_t* unpadded_row_size,
-      uint32_t* padded_row_size);
+      int alignment, uint32_t* size, uint32_t* opt_unpadded_row_size,
+      uint32_t* opt_padded_row_size);
+
+  // Similar to the above function, but taking into consideration all ES3
+  // pixel pack/unpack parameters.
+  // Optionally the skipped bytes in the beginning can be returned.
+  // Note the returned |size| does NOT include |skip_size|.
+  // TODO(zmo): merging ComputeImageDataSize and ComputeImageDataSizeES3.
+  static bool ComputeImageDataSizesES3(
+      int width, int height, int depth, int format, int type,
+      const PixelStoreParams& params,
+      uint32_t* size, uint32_t* opt_unpadded_row_size,
+      uint32_t* opt_padded_row_size, uint32_t* opt_skip_size);
 
   static size_t RenderbufferBytesPerPixel(int format);
 
@@ -192,6 +219,10 @@ class GLES2_UTILS_EXPORT GLES2Util {
   static std::string GetQualifiedEnumString(
       const EnumToString* table, size_t count, uint32_t value);
 
+  static bool ComputeImageRowSizeHelper(
+      int width, uint32 bytes_per_group, int alignment,
+      uint32* rt_unpadded_row_size, uint32* rt_padded_row_size);
+
   static const EnumToString* const enum_to_string_table_;
   static const size_t enum_to_string_table_len_;
 
diff --git a/gpu/command_buffer/common/gles2_cmd_utils_unittest.cc b/gpu/command_buffer/common/gles2_cmd_utils_unittest.cc
index 3eb2a38..a435f28 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils_unittest.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils_unittest.cc
@@ -320,6 +320,123 @@ TEST_F(GLES2UtilTest, ComputeImageDataSizeDepth) {
   EXPECT_EQ(kWidth * 3 + 7, padded_row_size);
 }
 
+TEST_F(GLES2UtilTest, ComputeImageDataSizePixelStoreParams) {
+  const uint32_t kWidth = 3;
+  const uint32_t kHeight = 3;
+  const uint32_t kDepth = 3;
+  uint32_t size;
+  uint32_t unpadded_row_size;
+  uint32_t padded_row_size;
+  uint32_t skip_size;
+
+  {  // Default
+    PixelStoreParams params;
+    EXPECT_TRUE(GLES2Util::ComputeImageDataSizesES3(
+        kWidth, kHeight, kDepth, GL_RGB, GL_UNSIGNED_BYTE, params,
+        &size, &unpadded_row_size, &padded_row_size, &skip_size));
+    EXPECT_EQ(kWidth * 3, unpadded_row_size);
+    EXPECT_EQ(kWidth * 3 + 3, padded_row_size);
+    EXPECT_EQ(padded_row_size * (kHeight * kDepth - 1) + unpadded_row_size,
+              size);
+    EXPECT_EQ(0u, skip_size);
+  }
+
+  {  // row_length > width
+    PixelStoreParams params;
+    params.row_length = kWidth + 2;
+    uint32_t kPadding = 1;  // 5 * 3 = 15 -> 16
+    EXPECT_TRUE(GLES2Util::ComputeImageDataSizesES3(
+        kWidth, kHeight, kDepth, GL_RGB, GL_UNSIGNED_BYTE, params,
+        &size, &unpadded_row_size, &padded_row_size, &skip_size));
+    EXPECT_EQ(static_cast<uint32_t>(kWidth * 3), unpadded_row_size);
+    EXPECT_EQ(static_cast<uint32_t>(params.row_length * 3 + kPadding),
+              padded_row_size);
+    EXPECT_EQ(padded_row_size * (kHeight * kDepth - 1) + unpadded_row_size,
+              size);
+    EXPECT_EQ(0u, skip_size);
+  }
+
+  {  // row_length < width
+    PixelStoreParams params;
+    params.row_length = kWidth - 1;
+    uint32_t kPadding = 2;  // 2 * 3 = 6 -> 8
+    EXPECT_TRUE(GLES2Util::ComputeImageDataSizesES3(
+        kWidth, kHeight, kDepth, GL_RGB, GL_UNSIGNED_BYTE, params,
+        &size, &unpadded_row_size, &padded_row_size, &skip_size));
+    EXPECT_EQ(static_cast<uint32_t>(kWidth * 3), unpadded_row_size);
+    EXPECT_EQ(static_cast<uint32_t>(params.row_length * 3 + kPadding),
+              padded_row_size);
+    EXPECT_EQ(padded_row_size * (kHeight * kDepth - 1) + unpadded_row_size,
+              size);
+    EXPECT_EQ(0u, skip_size);
+  }
+
+  {  // image_height > height
+    PixelStoreParams params;
+    params.image_height = kHeight + 1;
+    uint32_t kPadding = 3; // 3 * 3 = 9 -> 21
+    EXPECT_TRUE(GLES2Util::ComputeImageDataSizesES3(
+        kWidth, kHeight, kDepth, GL_RGB, GL_UNSIGNED_BYTE, params,
+        &size, &unpadded_row_size, &padded_row_size, &skip_size));
+    EXPECT_EQ(kWidth * 3, unpadded_row_size);
+    EXPECT_EQ(kWidth * 3 + kPadding, padded_row_size);
+    EXPECT_EQ((params.image_height * (kDepth - 1) + kHeight - 1) *
+              padded_row_size + unpadded_row_size, size);
+    EXPECT_EQ(0u, skip_size);
+  }
+
+  {  // image_height < height
+    PixelStoreParams params;
+    params.image_height = kHeight - 1;
+    uint32_t kPadding = 3; // 3 * 3 = 9 -> 12
+    EXPECT_TRUE(GLES2Util::ComputeImageDataSizesES3(
+        kWidth, kHeight, kDepth, GL_RGB, GL_UNSIGNED_BYTE, params,
+        &size, &unpadded_row_size, &padded_row_size, &skip_size));
+    EXPECT_EQ(kWidth * 3, unpadded_row_size);
+    EXPECT_EQ(kWidth * 3 + kPadding, padded_row_size);
+    EXPECT_EQ((params.image_height * (kDepth - 1) + kHeight - 1) *
+              padded_row_size + unpadded_row_size, size);
+    EXPECT_EQ(0u, skip_size);
+  }
+
+  {  // skip_pixels, skip_rows, skip_images, alignment = 4, RGB
+    PixelStoreParams params;
+    params.skip_pixels = 1;
+    params.skip_rows = 10;
+    params.skip_images = 2;
+    uint32_t kPadding = 3; // 3 * 3 = 9 -> 12
+    EXPECT_TRUE(GLES2Util::ComputeImageDataSizesES3(
+        kWidth, kHeight, kDepth, GL_RGB, GL_UNSIGNED_BYTE, params,
+        &size, &unpadded_row_size, &padded_row_size, &skip_size));
+    EXPECT_EQ(kWidth * 3, unpadded_row_size);
+    EXPECT_EQ(kWidth * 3 + kPadding, padded_row_size);
+    EXPECT_EQ(padded_row_size * kHeight * params.skip_images +
+              padded_row_size * params.skip_rows + 3 * params.skip_pixels,
+              skip_size);
+    EXPECT_EQ(padded_row_size * (kWidth * kDepth - 1) + unpadded_row_size,
+              size);
+  }
+
+  {  // skip_pixels, skip_rows, skip_images, alignment = 8, RGBA
+    PixelStoreParams params;
+    params.skip_pixels = 1;
+    params.skip_rows = 10;
+    params.skip_images = 2;
+    params.alignment = 8;
+    uint32_t kPadding = 4; // 3 * 4 = 12 -> 16
+    EXPECT_TRUE(GLES2Util::ComputeImageDataSizesES3(
+        kWidth, kHeight, kDepth, GL_RGBA, GL_UNSIGNED_BYTE, params,
+        &size, &unpadded_row_size, &padded_row_size, &skip_size));
+    EXPECT_EQ(kWidth * 4, unpadded_row_size);
+    EXPECT_EQ(kWidth * 4 + kPadding, padded_row_size);
+    EXPECT_EQ(padded_row_size * kHeight * params.skip_images +
+              padded_row_size * params.skip_rows + 4 * params.skip_pixels,
+              skip_size);
+    EXPECT_EQ(padded_row_size * (kWidth * kDepth - 1) + unpadded_row_size,
+              size);
+  }
+}
+
 TEST_F(GLES2UtilTest, RenderbufferBytesPerPixel) {
    EXPECT_EQ(1u, GLES2Util::RenderbufferBytesPerPixel(GL_STENCIL_INDEX8));
    EXPECT_EQ(2u, GLES2Util::RenderbufferBytesPerPixel(GL_RGBA4));