FreeType on OpenGL ES (iPhone)

#include "PreCompile.h"
#include "FTBitmapChar.h"
#include "GLCallBatcher.h"
#include "ResManager.h"
#include <freetype/ftglyph.h>


FTBitmapChar::FTBitmapChar()
{
	m_x = 0;
	m_y = 0;
	m_width = 0;
	m_height = 0;
	m_xOffset = 0;
	m_yOffset = 0;
	m_xAdvance = 0;
	m_pGlyph = NULL;
}

FTBitmapChar::~FTBitmapChar()
{
}

	

void FTBitmapChar::InitTexCoords(int texWidth, int texHeight)
{
	float x1 = (float)m_x/(float)texWidth;
	float y1 = (float)m_y/(float)texHeight;
	float x2 = (float)(m_x+m_width)/(float)texWidth;
	float y2 = (float)(m_y+m_height)/(float)texHeight;

	m_texCoords[0] = x1;
	m_texCoords[1] = y1;

	m_texCoords[2] = x2;
	m_texCoords[3] = y1;

	m_texCoords[4] = x1;
	m_texCoords[5] = y2;

	m_texCoords[6] = x2;
	m_texCoords[7] = y2;
}

// setup quad and draw as triangle groups
void FTBitmapChar::Render(int x, int y) const
{
	if (IsEmpty()) return;
	x += m_xOffset;	
	y += m_yOffset;
	float vertices[verticesPerQuad*compVertPos];
	vertices[0] = (float)x;
	vertices[1] = (float)y;

	vertices[2] = (float)(x+m_width);
	vertices[3] = (float)y;

	vertices[4] = (float)x;
	vertices[5] = (float)(y+m_height);

	vertices[6] = (float)(x+m_width);
	vertices[7] = (float)(y+m_height);
	g_resManager.GetBatcher().AddQuad(m_texCoords, vertices);
} // end of draw()


void FTBitmapChar::DrawToBitmap(unsigned char* pData, int texWidth, int texHeight) 
{
	if (IsEmpty()) return;
	InitTexCoords(texWidth, texHeight);
	// Convert The Glyph To A Bitmap.
	FT_Glyph_To_Bitmap(&m_pGlyph, FT_RENDER_MODE_NORMAL, 0, 1);
	FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph)m_pGlyph;

	// This Reference Will Make Accessing The Bitmap Easier.
	FT_Bitmap& bitmap = bitmap_glyph->bitmap;

	assert(bitmap.width == m_width);
	assert(bitmap.rows == m_height);
	int x, y = 0;
	int index;
	for (y = 0; y < bitmap.rows; y++)
	{
		for (x = 0; x < bitmap.width; x++)
		{
			index = (m_y+y)* texWidth + m_x + x;
			pData[index] = bitmap.buffer[y*bitmap.width + x];
		}
	}
}

void FTBitmapChar::ReleaseGlyph() 
{
	if (m_pGlyph) FT_Done_Glyph(m_pGlyph);
}