bullet3/examples/OpenGLWindow/GwenOpenGL3CoreRenderer.h

#ifndef __GWEN_OPENGL3_CORE_RENDERER_H
#define __GWEN_OPENGL3_CORE_RENDERER_H

#include "Gwen/Gwen.h"
#include "Gwen/BaseRender.h"
#include "GLPrimitiveRenderer.h"
#include "../OpenGLWindow/OpenGLInclude.h"

struct sth_stash;
#include "fontstash.h"
#include "Gwen/Texture.h"

#include "TwFonts.h"
static float extraSpacing = 0.;//6f;
#include <assert.h>
#include <math.h>

template <class T>
inline void MyClamp(T& a, const T& lb, const T& ub) 
{
	if (a < lb) 
	{
		a = lb; 
	}
	else if (ub < a) 
	{
		a = ub;
	}
}


static GLuint BindFont(const CTexFont *_Font)
{
    GLuint TexID = 0;
    glGenTextures(1, &TexID);
    glBindTexture(GL_TEXTURE_2D, TexID);
    glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);
    glPixelStorei(GL_UNPACK_LSB_FIRST, GL_FALSE);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, _Font->m_TexWidth, _Font->m_TexHeight, 0, GL_RED, GL_UNSIGNED_BYTE, _Font->m_TexBytes);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_NEAREST);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_NEAREST);
    glBindTexture(GL_TEXTURE_2D, 0);

    return TexID;
}

struct MyTextureLoader
{
	virtual ~MyTextureLoader()
	{
	}
	virtual void LoadTexture( Gwen::Texture* pTexture ) = 0;
	virtual void FreeTexture( Gwen::Texture* pTexture )=0;
};

class GwenOpenGL3CoreRenderer : public Gwen::Renderer::Base
{
	GLPrimitiveRenderer* m_primitiveRenderer;
	float m_currentColor[4];
	float m_yOffset;
    sth_stash* m_font;
    float m_screenWidth;
    float m_screenHeight;
    float m_fontScaling;
    float m_retinaScale;
	bool	m_useTrueTypeFont;
	const CTexFont* m_currentFont;
	
	GLuint	m_fontTextureId;
	MyTextureLoader* m_textureLoader;
public:
	GwenOpenGL3CoreRenderer (GLPrimitiveRenderer* primRender, sth_stash* font,float screenWidth, float screenHeight, float retinaScale, MyTextureLoader* loader=0)
		:m_primitiveRenderer(primRender),
    m_font(font),
    m_screenWidth(screenWidth),
    m_screenHeight(screenHeight),
    m_retinaScale(retinaScale),
	m_useTrueTypeFont(false),
	m_textureLoader(loader)
	{
		///only enable true type fonts on Macbook Retina, it looks gorgeous
		if (retinaScale==2.0f)
		{
			m_useTrueTypeFont = true;
		}
		m_currentColor[0] = 1;
		m_currentColor[1] = 1;
		m_currentColor[2] = 1;
		m_currentColor[3] = 1;
        
        m_fontScaling = 16.f*m_retinaScale;
		
		TwGenerateDefaultFonts();

		m_currentFont = g_DefaultNormalFont;
		//m_currentFont = g_DefaultNormalFontAA;

		//m_currentFont = g_DefaultLargeFont;
		m_fontTextureId = BindFont(m_currentFont);
		
	}

	virtual ~GwenOpenGL3CoreRenderer()
	{
		TwDeleteDefaultFonts();
	}
	virtual void Resize(int width, int height)
	{
		m_screenWidth = width;
		m_screenHeight = height;
	}
	
	virtual void Begin()
	{
		m_yOffset=0;
		glEnable(GL_BLEND);
	  assert(glGetError()==GL_NO_ERROR);


		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
		
		assert(glGetError()==GL_NO_ERROR);

		assert(glGetError()==GL_NO_ERROR);
        
		glDisable(GL_DEPTH_TEST);
		assert(glGetError()==GL_NO_ERROR);      
		//glColor4ub(255,0,0,255);
		
		
		
		glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);

	//	saveOpenGLState(width,height);//m_glutScreenWidth,m_glutScreenHeight);
			
		assert(glGetError()==GL_NO_ERROR);
			

		glDisable(GL_CULL_FACE);

		glDisable(GL_DEPTH_TEST);
		assert(glGetError()==GL_NO_ERROR);

		        
		glEnable(GL_BLEND);

		assert(glGetError()==GL_NO_ERROR);        
	}
	virtual void End()
	{
		glDisable(GL_BLEND);
		
	}

	virtual void StartClip()
	{
		if (m_useTrueTypeFont)
			sth_flush_draw(m_font);
		Gwen::Rect rect = ClipRegion();

		// OpenGL's coords are from the bottom left
		// so we need to translate them here.
		{
			GLint view[4];
			glGetIntegerv( GL_VIEWPORT, &view[0] );
			rect.y = view[3]/m_retinaScale - (rect.y + rect.h);
		}

		glScissor( m_retinaScale * rect.x * Scale(), m_retinaScale * rect.y * Scale(), m_retinaScale * rect.w * Scale(), m_retinaScale * rect.h * Scale() );
		glEnable( GL_SCISSOR_TEST );
		//glDisable( GL_SCISSOR_TEST );
		
	};

	virtual void EndClip()
	{
		if (m_useTrueTypeFont)
			sth_flush_draw(m_font);
		glDisable( GL_SCISSOR_TEST );
	};

	virtual void SetDrawColor( Gwen::Color color )
	{
		m_currentColor[0] = color.r/256.f;
		m_currentColor[1] = color.g/256.f;
		m_currentColor[2] = color.b/256.f;
		m_currentColor[3] = color.a/256.f;

	}
	virtual void DrawFilledRect( Gwen::Rect rect )
	{
		Translate( rect );

		m_primitiveRenderer->drawRect(rect.x, rect.y+m_yOffset, rect.x+rect.w, rect.y+rect.h+m_yOffset, m_currentColor);
//		m_yOffset+=rect.h+10;

	}
    
    void RenderText( Gwen::Font* pFont, Gwen::Point rasterPos, const Gwen::UnicodeString& text )
    {
		
        Gwen::String str = Gwen::Utility::UnicodeToString(text);
        const char* unicodeText = (const char*)str.c_str();
        
        Gwen::Rect r;
        r.x = rasterPos.x;
        r.y = rasterPos.y;
        r.w = 0;
        r.h = 0;
    
        
      //
        //printf("str = %s\n",unicodeText);
        //int xpos=0;
        //int ypos=0;
        float dx;
        
        int measureOnly=0;
        
		if (m_useTrueTypeFont)
		{
			
			float yoffset = 0.f;
			if (m_retinaScale==2.0f)
			{
				yoffset = -12;
			}
			Translate(r);
			sth_draw_text(m_font,
                      1,m_fontScaling,
                      r.x,r.y+yoffset,
                      unicodeText,&dx, m_screenWidth,m_screenHeight,measureOnly,m_retinaScale);
			 
		} else
		{
			//float width = 0.f;
			int pos=0;
			//float color[]={0.2f,0.2,0.2f,1.f};
		
			glBindTexture(GL_TEXTURE_2D,m_fontTextureId);
			float width = r.x;
			while (unicodeText[pos])
			{
				int c = unicodeText[pos];
				r.h = m_currentFont->m_CharHeight;
				r.w = m_currentFont->m_CharWidth[c]+extraSpacing;
				Gwen::Rect rect = r;
				Translate( rect );

				m_primitiveRenderer->drawTexturedRect(rect.x, rect.y+m_yOffset, rect.x+rect.w, rect.y+rect.h+m_yOffset, m_currentColor,m_currentFont->m_CharU0[c],m_currentFont->m_CharV0[c],m_currentFont->m_CharU1[c],m_currentFont->m_CharV1[c]);

				//DrawTexturedRect(0,r,m_currentFont->m_CharU0[c],m_currentFont->m_CharV0[c],m_currentFont->m_CharU1[c],m_currentFont->m_CharV1[c]);
			//	DrawFilledRect(r);

			
			
				width += r.w;
				r.x = width;
				pos++;
				
			}
			glBindTexture(GL_TEXTURE_2D,0);
		}

    }
    Gwen::Point MeasureText( Gwen::Font* pFont, const Gwen::UnicodeString& text )
    {
        Gwen::String str = Gwen::Utility::UnicodeToString(text);
        const char* unicodeText = (const char*)str.c_str();
        
       // printf("str = %s\n",unicodeText);
        int xpos=0;
        int ypos=0;
        
        
        int measureOnly=1;
		float dx=0;
		if (m_useTrueTypeFont)
		{
			sth_draw_text(m_font,
                      1,m_fontScaling,
                      xpos,ypos,
                      unicodeText,&dx, m_screenWidth,m_screenHeight,measureOnly);
		
			Gwen::Point pt;
			
			if (m_retinaScale==2.0f)
			{
				pt.x = dx*Scale()/2.f;
				pt.y = m_fontScaling/2*Scale()+1;
			}
			else
			{
				pt.x = dx*Scale();
				pt.y = m_fontScaling*Scale()+1;
			}
			return pt;
		}
		else
		{
			float width = 0.f;
			int pos=0;
			while (unicodeText[pos])
			{
				width += m_currentFont->m_CharWidth[(int)unicodeText[pos]]+extraSpacing;
				pos++;
			}
			Gwen::Point pt;
			int fontHeight = m_currentFont->m_CharHeight;


			pt.x = width*Scale();
			pt.y = (fontHeight+2) * Scale();

			return pt;
		}

		return Gwen::Renderer::Base::MeasureText(pFont,text);
    }

	
	virtual void LoadTexture( Gwen::Texture* pTexture )
	{
		if (m_textureLoader)
			m_textureLoader->LoadTexture(pTexture);
	}
	virtual void FreeTexture( Gwen::Texture* pTexture )
	{
		if (m_textureLoader)
			m_textureLoader->FreeTexture(pTexture);

	}
	
	
	virtual void DrawTexturedRect( Gwen::Texture* pTexture, Gwen::Rect rect, float u1=0.0f, float v1=0.0f, float u2=1.0f, float v2=1.0f )
	{

		Translate( rect );

		//float eraseColor[4] = {0,0,0,0};
		//m_primitiveRenderer->drawRect(rect.x, rect.y+m_yOffset, rect.x+rect.w, rect.y+rect.h+m_yOffset, eraseColor);

		GLint texHandle = (GLint) pTexture->m_intData;
		//if (!texHandle)
		//	return;
		
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D,texHandle);
//		glDisable(GL_DEPTH_TEST);

		assert(glGetError()==GL_NO_ERROR);
		
	
/*	bool useFiltering = true;
	if (useFiltering)
	{
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	} else
	{
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	}
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
*/
	
	//glEnable(GL_TEXTURE_2D);
	
		
		
//	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_NONE );
	static float add=0.0;
	//add+=1./512.;//0.01;
	float color[4]={1,1,1,1};

	m_primitiveRenderer->drawTexturedRect(rect.x, rect.y+m_yOffset, rect.x+rect.w, rect.y+rect.h+m_yOffset, color,0+add,0,1+add,1,true);

		
				assert(glGetError()==GL_NO_ERROR);

		
		
	}
			
};
#endif //__GWEN_OPENGL3_CORE_RENDERER_H