(TextAtlas) Bilt 2 pixels to avoid texture coordinate issue

We use 0.5 scaled texel coordinate for atlas texture.

For some cases, we might re-use texture coordinate what previous glyph written.
In this case, for some graphic driver try to use some color
over the bilt area.

To avoid this cases, let we fill bilt area width as 2 pixels, instead 1 pixel.

Change-Id: I8c3aa72f2c2ec43cb7a79d018b0972deab51935a
Signed-off-by: Eunki, Hong <eunkiki.hong@samsung.com>

diff --git a/dali-toolkit/internal/text/rendering/atlas/atlas-manager-impl.cpp b/dali-toolkit/internal/text/rendering/atlas/atlas-manager-impl.cpp
index 0308691973afb41df6ec6581e0406da07d996dba..8a09f5007f0c96a1b71de86e42df766d9488dcea 100644 (file)
--- a/dali-toolkit/internal/text/rendering/atlas/atlas-manager-impl.cpp
+++ b/dali-toolkit/internal/text/rendering/atlas/atlas-manager-impl.cpp
@@ -32,12 +32,14 @@ namespace Internal
 {
 namespace
 {
-const uint32_t                   DEFAULT_ATLAS_WIDTH(512u);
-const uint32_t                   DEFAULT_ATLAS_HEIGHT(512u);
-const uint32_t                   DEFAULT_BLOCK_WIDTH(16u);
-const uint32_t                   DEFAULT_BLOCK_HEIGHT(16u);
-const uint32_t                   SINGLE_PIXEL_PADDING(1u);
-const uint32_t                   DOUBLE_PIXEL_PADDING(SINGLE_PIXEL_PADDING << 1);
+constexpr uint32_t DEFAULT_ATLAS_WIDTH(512u);
+constexpr uint32_t DEFAULT_ATLAS_HEIGHT(512u);
+constexpr uint32_t DEFAULT_BLOCK_WIDTH(16u);
+constexpr uint32_t DEFAULT_BLOCK_HEIGHT(16u);
+constexpr uint32_t SINGLE_PIXEL_PADDING(1u);
+constexpr uint32_t DOUBLE_PIXEL_PADDING(SINGLE_PIXEL_PADDING << 1);
+constexpr uint32_t TRIPLE_PIXEL_PADDING(DOUBLE_PIXEL_PADDING + SINGLE_PIXEL_PADDING);
+
 Toolkit::AtlasManager::AtlasSize EMPTY_SIZE;
 
 bool IsBlockSizeSufficient(uint32_t width, uint32_t height, uint32_t requiredBlockWidth, uint32_t requiredBlockHeight)
@@ -254,7 +256,7 @@ void AtlasManager::UploadImage(const PixelData&           image,
                                const AtlasSlotDescriptor& desc)
 {
   // Get the atlas to upload the image to
-  SizeType atlas = desc.mAtlasId - 1u;
+  const SizeType atlas = desc.mAtlasId - 1u;
 
   // Check to see that the pixel formats are compatible
   if(image.GetPixelFormat() != mAtlasList[atlas].mPixelFormat)
@@ -263,52 +265,103 @@ void AtlasManager::UploadImage(const PixelData&           image,
     return;
   }
 
-  SizeType atlasBlockWidth    = mAtlasList[atlas].mSize.mBlockWidth;
-  SizeType atlasBlockHeight   = mAtlasList[atlas].mSize.mBlockHeight;
-  SizeType atlasWidthInBlocks = (mAtlasList[atlas].mSize.mWidth - 1u) / mAtlasList[atlas].mSize.mBlockWidth;
-
-  SizeType blockX       = desc.mBlock % atlasWidthInBlocks;
-  SizeType blockY       = desc.mBlock / atlasWidthInBlocks;
-  SizeType blockOffsetX = (blockX * atlasBlockWidth) + 1u;
-  SizeType blockOffsetY = (blockY * atlasBlockHeight) + 1u;
-
-  SizeType width  = image.GetWidth();
-  SizeType height = image.GetHeight();
-
-  // Blit image 1 pixel to the right and down into the block to compensate for texture filtering
-  if(!mAtlasList[atlas].mAtlas.Upload(image, 0u, 0u, blockOffsetX + SINGLE_PIXEL_PADDING, blockOffsetY + SINGLE_PIXEL_PADDING, width, height))
+  const SizeType atlasBlockWidth    = mAtlasList[atlas].mSize.mBlockWidth;
+  const SizeType atlasBlockHeight   = mAtlasList[atlas].mSize.mBlockHeight;
+  const SizeType atlasWidthInBlocks = (mAtlasList[atlas].mSize.mWidth - 1u) / mAtlasList[atlas].mSize.mBlockWidth;
+
+  const SizeType blockX       = desc.mBlock % atlasWidthInBlocks;
+  const SizeType blockY       = desc.mBlock / atlasWidthInBlocks;
+  const SizeType blockOffsetX = (blockX * atlasBlockWidth);
+  const SizeType blockOffsetY = (blockY * atlasBlockHeight);
+  const SizeType imageOffsetX = blockOffsetX + DOUBLE_PIXEL_PADDING;
+  const SizeType imageOffsetY = blockOffsetY + DOUBLE_PIXEL_PADDING;
+
+  const SizeType width  = image.GetWidth();
+  const SizeType height = image.GetHeight();
+
+  const auto horizontalStripWidth  = mAtlasList[atlas].mHorizontalStrip.GetWidth();
+  const auto horizontalStripHeight = mAtlasList[atlas].mHorizontalStrip.GetHeight(); ///< Must be 1
+  const auto verticalStripWidth    = mAtlasList[atlas].mVerticalStrip.GetWidth();    ///< Must be 1
+  const auto verticalStripHeight   = mAtlasList[atlas].mVerticalStrip.GetHeight();
+
+  DALI_ASSERT_DEBUG(horizontalStripHeight == SINGLE_PIXEL_PADDING && verticalStripWidth == SINGLE_PIXEL_PADDING && "Strip buffer size invalid!");
+
+  const SizeType firstRowBlitOffset = (blockOffsetX == 0u || blockOffsetY == 0u) ? 1u : 0u;
+
+  /**
+   * Uploading image and blit to Atlas.
+   *
+   * |------------- atlasWidth ----------------|
+   * |-- atlasBlockWidth ---|-----------------|| << A)
+   * |-|------|             |-|----|             << B)
+   * *<....................><.................>. << C)
+   * <.....................><.................>. << D)
+   * ^^+------+^^...........^^+----+^^.......... << E)
+   * ..| /---\|...............|\  /|............
+   * ..| |   ||...............| \/ |............
+   * ..| \---/|...............+----+............
+   * ..+------+.............<.................>. << D)
+   * <.....................><.................>.
+   * <.....................>....................
+   * vv........vv...........vv......vv.......... << E)
+   * ...........................................
+   * ...........................................
+   *
+   *
+   * A) The right-most block right offset have at least one-pixel.
+   * B) Each glyph have double-pixel-padding from the top-left
+   *    corner of the block.
+   * C) (0, 0) pixel has special color for underline and strikethrough.
+   *
+   * D) Horizontal strips are blitted double-pixeld above and below the
+   *    image. The width of strip is same as block size
+   * E) Vertical strips are blitted double-pixels to the left and right
+   *    of the image. The height of strip is same as (block size - 2)
+   *
+   * Note : We can overwrite the image to Atlas which where be used before.
+   * To make ensure that previous color is cleared, we should add
+   * double-pixel-padding blit the image to Atlas every time.
+   */
+
+  [[maybe_unused]] bool uploaded = true;
+
+  // Blit image 2 pixel to the right and down into the block to compensate for texture filtering
+  uploaded = mAtlasList[atlas].mAtlas.Upload(image, 0u, 0u, imageOffsetX, imageOffsetY, width, height);
+  DALI_ASSERT_DEBUG(uploaded && "Uploading image to Atlas Failed!");
+
+  // Blit top 2 strip (Note that we should not blit the 0,0 pixel since it is special color for underline and strikethrough)
+  if(horizontalStripWidth > firstRowBlitOffset)
   {
-    DALI_LOG_ERROR("Uploading image to Atlas Failed!.\n");
+    uploaded = mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mHorizontalStrip, 0u, 0u, blockOffsetX + firstRowBlitOffset, blockOffsetY, horizontalStripWidth - firstRowBlitOffset, horizontalStripHeight);
   }
+  uploaded &= mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mHorizontalStrip, 0u, 0u, blockOffsetX, blockOffsetY + SINGLE_PIXEL_PADDING, horizontalStripWidth, horizontalStripHeight);
+  DALI_ASSERT_DEBUG(uploaded && "Uploading top strip to Atlas Failed!");
 
-  // Blit top strip
-  if(!mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mHorizontalStrip, 0u, 0u, blockOffsetX, blockOffsetY, mAtlasList[atlas].mHorizontalStrip.GetWidth(), mAtlasList[atlas].mHorizontalStrip.GetHeight()))
-  {
-    DALI_LOG_ERROR("Uploading top strip to Atlas Failed!\n");
-  }
-
-  // Blit left strip
-  if(!mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mVerticalStrip, 0u, 0u, blockOffsetX, blockOffsetY + SINGLE_PIXEL_PADDING, mAtlasList[atlas].mVerticalStrip.GetWidth(), mAtlasList[atlas].mVerticalStrip.GetHeight()))
-  {
-    DALI_LOG_ERROR("Uploading left strip to Atlas Failed!\n");
-  }
+  // Blit left 2 strip
+  uploaded = mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mVerticalStrip, 0u, 0u, blockOffsetX, imageOffsetY, verticalStripWidth, verticalStripHeight);
+  uploaded &= mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mVerticalStrip, 0u, 0u, blockOffsetX + SINGLE_PIXEL_PADDING, imageOffsetY, verticalStripWidth, verticalStripHeight);
+  DALI_ASSERT_DEBUG(uploaded && "Uploading left strip to Atlas Failed!");
 
-  // Blit bottom strip
-  if(blockOffsetY + height + DOUBLE_PIXEL_PADDING <= mAtlasList[atlas].mSize.mHeight)
+  // Blit bottom 2 strip
+  if(blockOffsetY + height + DOUBLE_PIXEL_PADDING < mAtlasList[atlas].mSize.mHeight)
   {
-    if(!mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mHorizontalStrip, 0u, 0u, blockOffsetX, blockOffsetY + height + SINGLE_PIXEL_PADDING, mAtlasList[atlas].mHorizontalStrip.GetWidth(), mAtlasList[atlas].mHorizontalStrip.GetHeight()))
+    uploaded = mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mHorizontalStrip, 0u, 0u, blockOffsetX, blockOffsetY + height + DOUBLE_PIXEL_PADDING, horizontalStripWidth, horizontalStripHeight);
+    if(blockOffsetY + height + TRIPLE_PIXEL_PADDING < mAtlasList[atlas].mSize.mHeight)
     {
-      DALI_LOG_ERROR("Uploading bottom strip to Atlas Failed!.\n");
+      uploaded &= mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mHorizontalStrip, 0u, 0u, blockOffsetX, blockOffsetY + height + TRIPLE_PIXEL_PADDING, horizontalStripWidth, horizontalStripHeight);
     }
+    DALI_ASSERT_DEBUG(uploaded && "Uploading bottom strip to Atlas Failed!.");
   }
 
-  // Blit right strip
-  if(blockOffsetX + width + DOUBLE_PIXEL_PADDING <= mAtlasList[atlas].mSize.mWidth)
+  // Blit right 2 strip
+  if(blockOffsetX + width + DOUBLE_PIXEL_PADDING < mAtlasList[atlas].mSize.mWidth)
   {
-    if(!mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mVerticalStrip, 0u, 0u, blockOffsetX + width + SINGLE_PIXEL_PADDING, blockOffsetY + SINGLE_PIXEL_PADDING, mAtlasList[atlas].mVerticalStrip.GetWidth(), mAtlasList[atlas].mVerticalStrip.GetHeight()))
+    uploaded = mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mVerticalStrip, 0u, 0u, blockOffsetX + width + DOUBLE_PIXEL_PADDING, imageOffsetY, verticalStripWidth, verticalStripHeight);
+    if(blockOffsetX + width + TRIPLE_PIXEL_PADDING < mAtlasList[atlas].mSize.mWidth)
     {
-      DALI_LOG_ERROR("Uploading right strip to Atlas Failed!.\n");
+      uploaded &= mAtlasList[atlas].mAtlas.Upload(mAtlasList[atlas].mVerticalStrip, 0u, 0u, blockOffsetX + width + TRIPLE_PIXEL_PADDING, imageOffsetY, verticalStripWidth, verticalStripHeight);
     }
+    DALI_ASSERT_DEBUG(uploaded && "Uploading right strip to Atlas Failed!.");
   }
 }