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o3de/Gems/AtomLyIntegration/AtomFont/Code/Source/FontRenderer.cpp

328 lines
9.3 KiB
C++

/*
* Copyright (c) Contributors to the Open 3D Engine Project.
* For complete copyright and license terms please see the LICENSE at the root of this distribution.
*
* SPDX-License-Identifier: Apache-2.0 OR MIT
*
*/
//
// Purpose:
// - Render a glyph outline into a bitmap using FreeType 2
#if !defined(USE_NULLFONT_ALWAYS)
#include <AtomLyIntegration/AtomFont/FontRenderer.h>
#include <freetype/ftoutln.h>
#include <freetype/ftglyph.h>
#include <freetype/ftimage.h>
#include <AzCore/Casting/lossy_cast.h>
#include <CryCommon/ISystem.h>
// Sizes are defined in in 26.6 fixed float format (TT_F26Dot6), where
// 1 unit is 1/64 of a pixel.
constexpr int FractionalPixelUnits = 64;
namespace
{
FT_Int32 GetLoadFlags(AZ::FFont::HintBehavior hintBehavior)
{
switch (hintBehavior)
{
case AZ::FFont::HintBehavior::NoHinting:
{
return FT_LOAD_NO_HINTING;
break;
}
case AZ::FFont::HintBehavior::AutoHint:
{
return FT_LOAD_FORCE_AUTOHINT;
break;
}
}
return FT_LOAD_DEFAULT;
}
FT_Int32 GetLoadTarget(AZ::FFont::HintStyle hintStyle)
{
if (hintStyle == AZ::FFont::HintStyle::Light)
{
return FT_LOAD_TARGET_LIGHT;
}
return FT_LOAD_TARGET_NORMAL;
}
FT_Render_Mode GetRenderMode(AZ::FFont::HintStyle hintStyle)
{
// We use the hint style to drive the render mode also. These should
// usually be correlated with each other for best results, even though
// they could technically be different.
if (hintStyle == AZ::FFont::HintStyle::Light)
{
return FT_RENDER_MODE_LIGHT;
}
return FT_RENDER_MODE_NORMAL;
}
}
//-------------------------------------------------------------------------------------------------
AZ::FontRenderer::FontRenderer()
: m_library(0)
, m_face(0)
, m_glyph(0)
, m_sizeRatio(IFFontConstants::defaultSizeRatio)
, m_encoding(AZ_FONT_ENCODING_UNICODE)
, m_glyphBitmapWidth(0)
, m_glyphBitmapHeight(0)
{
}
//-------------------------------------------------------------------------------------------------
AZ::FontRenderer::~FontRenderer()
{
FT_Done_Face(m_face);
;
FT_Done_FreeType(m_library);
m_face = NULL;
m_library = NULL;
}
//-------------------------------------------------------------------------------------------------
int AZ::FontRenderer::LoadFromFile(const AZStd::string& fileName)
{
int iError = FT_Init_FreeType(&m_library);
if (iError)
{
return 0;
}
if (m_face)
{
FT_Done_Face(m_face);
m_face = 0;
}
iError = FT_New_Face(m_library, fileName.c_str(), 0, &m_face);
if (iError)
{
return 0;
}
SetEncoding(AZ_FONT_ENCODING_UNICODE);
return 1;
}
//-------------------------------------------------------------------------------------------------
int AZ::FontRenderer::LoadFromMemory(unsigned char* buffer, int bufferSize)
{
int iError = FT_Init_FreeType(&m_library);
if (iError)
{
return 0;
}
if (m_face)
{
FT_Done_Face(m_face);
m_face = 0;
}
iError = FT_New_Memory_Face(m_library, buffer, bufferSize, 0, &m_face);
if (iError)
{
return 0;
}
SetEncoding(AZ_FONT_ENCODING_UNICODE);
return 1;
}
//-------------------------------------------------------------------------------------------------
int AZ::FontRenderer::Release()
{
FT_Done_Face(m_face);
;
FT_Done_FreeType(m_library);
m_face = NULL;
m_library = NULL;
return 1;
}
//-------------------------------------------------------------------------------------------------
int AZ::FontRenderer::SetGlyphBitmapSize(int width, int height, float sizeRatio)
{
m_glyphBitmapWidth = width;
m_glyphBitmapHeight = height;
// Assign the given scale for texture slots as long as its positive
m_sizeRatio = sizeRatio > 0.0f ? sizeRatio : m_sizeRatio;
FT_Set_Pixel_Sizes(m_face, (int)(m_glyphBitmapWidth * m_sizeRatio), (int)(m_glyphBitmapHeight * m_sizeRatio));
return 1;
}
//-------------------------------------------------------------------------------------------------
int AZ::FontRenderer::GetGlyphBitmapSize(int* width, int* height)
{
if (width)
{
*width = m_glyphBitmapWidth;
}
if (height)
{
*height = m_glyphBitmapHeight;
}
return 1;
}
//-------------------------------------------------------------------------------------------------
int AZ::FontRenderer::SetEncoding(FT_Encoding encoding)
{
if (FT_Select_Charmap(m_face, encoding))
{
return 0;
}
return 1;
}
//-------------------------------------------------------------------------------------------------
//-------------------------------------------------------------------------------------------------
int AZ::FontRenderer::GetGlyph(GlyphBitmap* glyphBitmap, int* horizontalAdvance, uint8_t* glyphWidth, uint8_t* glyphHeight, int32_t& m_characterOffsetX, int32_t& m_characterOffsetY, int iX, int iY, int characterCode, const FFont::FontHintParams& fontHintParams)
{
FT_Int32 loadFlags = GetLoadFlags(fontHintParams.hintBehavior);
loadFlags |= GetLoadTarget(fontHintParams.hintStyle);
int iError = FT_Load_Char(m_face, characterCode, loadFlags);
if (iError)
{
return 0;
}
FT_Render_Mode renderMode = GetRenderMode(fontHintParams.hintStyle);
m_glyph = m_face->glyph;
iError = FT_Render_Glyph(m_glyph, renderMode);
if (iError)
{
return 0;
}
if (horizontalAdvance)
{
*horizontalAdvance = m_glyph->metrics.horiAdvance / FractionalPixelUnits;
}
if (glyphWidth)
{
*glyphWidth = static_cast<uint8_t>(m_glyph->bitmap.width);
}
if (glyphHeight)
{
*glyphHeight = static_cast<uint8_t>(m_glyph->bitmap.rows);
}
unsigned char* buffer = glyphBitmap->GetBuffer();
AZ_Assert(buffer, "GlyphBitmap: bad buffer");
uint32_t dwGlyphWidth = glyphBitmap->GetWidth();
m_characterOffsetX = m_glyph->bitmap_left;
m_characterOffsetY = (static_cast<int32_t>(round(m_glyphBitmapHeight * m_sizeRatio)) - m_glyph->bitmap_top);
const int textureSlotBufferWidth = glyphBitmap->GetWidth();
const int textureSlotBufferHeight = glyphBitmap->GetHeight();
// might happen if font characters are too big or cache dimenstions in font.xml is too small "<font path="VeraMono.ttf" w="320" h="368"/>"
const bool charWidthFits = static_cast<int>(iX + m_glyph->bitmap.width) <= textureSlotBufferWidth;
const bool charHeightFits = static_cast<int>(iY + m_glyph->bitmap.rows) <= textureSlotBufferHeight;
[[maybe_unused]] const bool charFitsInSlot = charWidthFits && charHeightFits;
AZ_Error("Font", charFitsInSlot, "Character code %d doesn't fit in font texture; check 'sizeRatio' attribute in font XML or adjust this character's sizing in the font.", characterCode);
// Since we might be re-rendering/overwriting a glyph that already exists
// in the font texture, clear the contents of this particular slot so no
// artifacts of the previous glyph remain.
glyphBitmap->Clear();
// Restrict iteration to smallest of either the texture slot or glyph
// bitmap buffer ranges
const int bufferMaxIterWidth = AZStd::GetMin<int>(textureSlotBufferWidth, m_glyph->bitmap.width);
const int bufferMaxIterHeight = AZStd::GetMin<int>(textureSlotBufferHeight, m_glyph->bitmap.rows);
for (int i = 0; i < bufferMaxIterHeight; i++)
{
int iNewY = i + iY;
for (int j = 0; j < bufferMaxIterWidth; j++)
{
unsigned char cColor = m_glyph->bitmap.buffer[(i * m_glyph->bitmap.width) + j];
int iOffset = iNewY * dwGlyphWidth + iX + j;
if (iOffset >= (int)dwGlyphWidth * m_glyphBitmapHeight)
{
continue;
}
buffer[iOffset] = cColor;
// buffer[iOffset] = cColor/2+32; // debug - visualize character in a block
}
}
return 1;
}
int AZ::FontRenderer::GetGlyphScaled([[maybe_unused]] GlyphBitmap* glyphBitmap, [[maybe_unused]] int* glyphWidth, [[maybe_unused]] int* glyphHeight, [[maybe_unused]] int iX, [[maybe_unused]] int iY, [[maybe_unused]] float scaleX, [[maybe_unused]] float scaleY, [[maybe_unused]] int characterCode)
{
return 1;
}
Vec2 AZ::FontRenderer::GetKerning(uint32_t leftGlyph, uint32_t rightGlyph)
{
FT_Vector kerningOffsets;
kerningOffsets.x = kerningOffsets.y = 0;
if (FT_HAS_KERNING(m_face))
{
const FT_UInt leftGlyphIndex = FT_Get_Char_Index(m_face, leftGlyph);
const FT_UInt rightGlyphIndex = FT_Get_Char_Index(m_face, rightGlyph);
[[maybe_unused]] FT_Error ftError = FT_Get_Kerning(m_face, leftGlyphIndex, rightGlyphIndex, FT_KERNING_DEFAULT, &kerningOffsets);
#if !defined(_RELEASE)
if (0 != ftError)
{
CryWarning(VALIDATOR_MODULE_SYSTEM, VALIDATOR_WARNING, "FT_Get_Kerning returned %d", ftError);
}
#endif
}
return Vec2(azlossy_cast<float>(kerningOffsets.x / FractionalPixelUnits), azlossy_cast<float>(kerningOffsets.y / FractionalPixelUnits));
}
float AZ::FontRenderer::GetAscenderToHeightRatio()
{
return (static_cast<float>(m_face->ascender) / static_cast<float>(m_face->height));
}
#endif // #if !defined(USE_NULLFONT_ALWAYS)