More editbox functionality

PortabilityLayer/TextPlacer.cpp

@@ -0,0 +1,151 @@
+#include "TextPlacer.h"
+
+#include "PLPasStr.h"
+#include "RenderedFontMetrics.h"
+#include "RenderedGlyphMetrics.h"
+#include "RenderedFont.h"
+
+#include <assert.h>
+
+namespace PortabilityLayer
+{
+	TextPlacer::TextPlacer(const Vec2i &basePoint, int32_t spanWidth, PortabilityLayer::RenderedFont *rfont, const PLPasStr &str)
+		: m_basePoint(basePoint)
+		, m_penPos(0, 0)
+		, m_paraStartPos(0, 0)
+		, m_rfont(rfont)
+		, m_chars(str.UChars())
+		, m_length(str.Length())
+		, m_currentStartChar(0)
+		, m_currentSpanLength(0)
+		, m_committedLength(0)
+		, m_emitOffset(0)
+		, m_haveCommitted(false)
+		, m_maxSpanWidth(spanWidth)
+	{
+	}
+
+	TextPlacer::~TextPlacer()
+	{
+	}
+
+	bool TextPlacer::PlaceGlyph(GlyphPlacementCharacteristics &outCharacteristics)
+	{
+		for (;;)
+		{
+			if (!m_haveCommitted)
+			{
+				if (m_currentStartChar == m_length)
+					return false;
+
+				size_t lastWhitespace = m_currentStartChar;
+				bool shouldSkipSpaces = false;
+
+				size_t committedLength = 0;
+
+				size_t i = m_currentStartChar;
+
+				// Find a span to print
+				int32_t spanWidth = 0;
+				for (;;)
+				{
+					if (i == m_length)
+					{
+						committedLength = i - m_currentStartChar;
+						break;
+					}
+
+					uint8_t character = m_chars[i];
+
+					if (character <= ' ')
+					{
+						committedLength = i - m_currentStartChar + 1;
+						if (character == '\r')
+							break;
+
+						const PortabilityLayer::RenderedGlyphMetrics *metrics = nullptr;
+						const void *glyphData = nullptr;
+						if (m_rfont->GetGlyph(m_chars[i], metrics, glyphData))
+							spanWidth += metrics->m_advanceX;
+
+						i++;
+					}
+					else
+					{
+						const PortabilityLayer::RenderedGlyphMetrics *metrics = nullptr;
+						const void *glyphData = nullptr;
+						if (!m_rfont->GetGlyph(m_chars[i], metrics, glyphData))
+						{
+							i++;
+							continue;
+						}
+
+						spanWidth += metrics->m_advanceX;
+
+						if (m_maxSpanWidth >= 0 && spanWidth > m_maxSpanWidth)
+						{
+							if (committedLength == 0)
+							{
+								// Word didn't fit
+								committedLength = i - m_currentStartChar;
+								if (committedLength == 0)
+									committedLength = 1;	// Nothing fit, consume one char
+							}
+
+							break;
+						}
+
+						i++;
+					}
+				}
+
+				m_haveCommitted = true;
+				m_committedLength = committedLength;
+				m_emitOffset = 0;
+			}
+
+			assert(m_emitOffset < m_committedLength);
+
+			const size_t charIndex = m_currentStartChar + m_emitOffset;
+			const uint8_t character = m_chars[charIndex];
+
+			outCharacteristics.m_glyphStartPos = m_penPos + m_basePoint;
+			outCharacteristics.m_glyphEndPos = outCharacteristics.m_glyphStartPos;
+			outCharacteristics.m_isParaStart = (m_emitOffset == 0);
+			outCharacteristics.m_isParaEnd = (m_emitOffset == m_committedLength - 1);
+			outCharacteristics.m_characterIndex = m_currentStartChar + m_emitOffset;
+			outCharacteristics.m_character = character;
+
+			const PortabilityLayer::RenderedGlyphMetrics *metrics;
+			const void *data;
+			if (!m_rfont->GetGlyph(character, metrics, data))
+			{
+				outCharacteristics.m_haveGlyph = false;
+				outCharacteristics.m_glyphMetrics = nullptr;
+				outCharacteristics.m_glyphData = nullptr;
+			}
+			else
+			{
+				m_penPos.m_x += metrics->m_advanceX;
+
+				outCharacteristics.m_haveGlyph = true;
+				outCharacteristics.m_glyphMetrics = metrics;
+				outCharacteristics.m_glyphData = data;
+				outCharacteristics.m_glyphEndPos.m_x += metrics->m_advanceX;
+			}
+
+			m_emitOffset++;
+
+			if (m_emitOffset == m_committedLength)
+			{
+				m_currentStartChar += m_committedLength;
+				m_haveCommitted = false;
+
+				m_paraStartPos.m_y += m_rfont->GetMetrics().m_linegap;
+				m_penPos = m_paraStartPos;
+			}
+
+			return true;
+		}
+	}
+}