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funnygame/external/steamworks/steamworksexample/StarField.cpp
2025-07-13 15:47:42 +03:00

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//========= Copyright <20> 1996-2008, Valve LLC, All rights reserved. ============
//
// Purpose: Class for rendering the starfield
//
// $NoKeywords: $
//=============================================================================
#include "stdafx.h"
#include "StarField.h"
#include "stdlib.h"
//-----------------------------------------------------------------------------
// Purpose: Constructor
//-----------------------------------------------------------------------------
CStarField::CStarField( IGameEngine *pGameEngine )
{
m_pGameEngine = pGameEngine;
Init();
}
void CStarField::Init()
{
StarVertex_t StarVertex;
m_nWidth = m_pGameEngine->GetViewportWidth();
m_nHeight = m_pGameEngine->GetViewportHeight();
m_VecStars.clear();
// Generate star field data
for( int i=0; i < STARFIELD_STAR_COUNT; ++i )
{
int32 nRand = (rand()%(255-50))+50; //value between 50 and 255 for shades of gray
StarVertex.color = D3DCOLOR_ARGB( 255, nRand, nRand, nRand );
StarVertex.x = (float)(rand()%m_nWidth);
StarVertex.y = (float)(rand()%m_nHeight);
m_VecStars.push_back( StarVertex );
// bugbug jmccaskey - sometimes make "big stars" which are 4 points right next to each other?
}
}
//-----------------------------------------------------------------------------
// Purpose: Render the star field
//-----------------------------------------------------------------------------
void CStarField::Render()
{
if ( ( m_pGameEngine->GetViewportWidth() != m_nWidth ) || ( m_pGameEngine->GetViewportHeight() != m_nHeight ) )
{
Init();
}
static int counter; // per starfield draw..
counter++;
for( size_t i = 0; i < m_VecStars.size(); ++i )
{
float x = m_VecStars[i].x;
float y = m_VecStars[i].y;
float scoot = (float)counter * (float)(m_VecStars[i].color & 0xFF) / (4.0f * 255.0f);
float newy = y - scoot; // make things float up
while( newy < 0.0f ) newy += m_nHeight; // keep it on screen
m_pGameEngine->BDrawPoint( x, newy, m_VecStars[i].color );
}
m_pGameEngine->BFlushPointBuffer();
}