www.pudn.com > SkyBox.zip > OGLRenderer.cpp
//-----------------------------------------------------------------------------
//
// @doc
//
// @module OGLRenderer.cpp - OpenGL renderer |
//
// This module contains the support for OpenGL rendering.
//
// Copyright (c) 1999 - Descartes Systems Sciences, Inc.
//
// @end
//
// $History: DcComEngGenConfigurePage.h $
//
//-----------------------------------------------------------------------------
#include "stdafx.h"
#include "OGLRenderer.h"
#include "RenderGlobals.h"
#include "../_CoreLib/Utility.h"
#include "../_CoreLib/Matrix.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
//
// Globals used by the renderer
//
HWND COGLRenderer::gs_hWnd;
HDC COGLRenderer::gs_hDC;
HGLRC COGLRenderer::gs_hrc;
//
// Force all render code into own seg
//
#pragma code_seg ("renderer_segment")
//
// Helper macros
//
#ifdef _DEBUG
#define CheckGlError() \
{ \
GLenum nError = glGetError (); \
_ASSERT (nError == GL_NO_ERROR); \
}
#else
#define CheckGlError()
#endif
inline void DoSkyCoord (const CSkyDome::_Vertex &sVertex, const TextureMatrix &tm)
{
CVector2 vTC;
vTC .m_x = sVertex .vVertex .Dot (tm .vsTexture) + tm .fsTexShift;
vTC .m_y = sVertex .vVertex .Dot (tm .vtTexture) + tm .ftTexShift;
glTexCoord2fv (vTC .m_v);
glVertex3fv (sVertex .vMapVertex .m_v);
}
inline void COGLRenderer::SetColor (const CVector4 &vColor)
{
if (!(vColor == g_vLastColor))
{
glColor4fv (vColor .m_v);
g_vLastColor = vColor;
}
}
//-----------------------------------------------------------------------------
//
// @mfunc Draw a cloud layer
//
// Draw a cloud layer
//
// @rdesc None.
//
//-----------------------------------------------------------------------------
void COGLRenderer::DrawSkyClouds (CSkyClouds *pSkyClouds,
const CVector3 &vColor)
{
int i;
//
// Selected the proper texture
//
BindTextureIndex (pSkyClouds ->GetTextureIndex ());
//
// Create the texture mapping object
//
CVector2 vOffset (pSkyClouds ->GetOffset ());
float fScale = 1.0 / (g_sSkyDome .m_fRadius * 2.0f * pSkyClouds ->GetScale ());
TextureMatrix tm;
tm .fsTexShift = .5f + vOffset .m_x;
tm .ftTexShift = .5f + vOffset .m_y;
tm .vsTexture = CVector3 (fScale, 0, 0);
tm .vtTexture = CVector3 (0, fScale, 0);
//
// Get a pointer to the vertex list to make things easier
//
CSkyDome::_Vertex *pVertex = g_sSkyDome .m_pVertex;
int nResolution = g_sSkyDome .m_nResolution;
//
// Loop through top row of triangles
//
SetColor (vColor);
glBegin (GL_TRIANGLE_FAN);
DoSkyCoord (pVertex [0], tm);
for (i = 1; i < nResolution * 4 + 1; i++)
{
DoSkyCoord (pVertex [i], tm);
}
DoSkyCoord (pVertex [1], tm);
glEnd ();
//
// Loop through squares
//
int nDelta = nResolution * 4;
for (int j = 1; j < nResolution; j++)
{
int nStart = nDelta * j + 1;
int nEnd = nStart + nDelta;
glBegin (GL_TRIANGLE_STRIP);
for (i = nStart; i < nEnd; i++)
{
DoSkyCoord (pVertex [i - nDelta], tm);
DoSkyCoord (pVertex [i], tm);
}
DoSkyCoord (pVertex [nStart - nDelta], tm);
DoSkyCoord (pVertex [nStart], tm);
glEnd ();
}
}
//-----------------------------------------------------------------------------
//
// @mfunc Draw a sky body
//
// Draw a sky body to the screen
//
// @rdesc None.
//
//-----------------------------------------------------------------------------
void COGLRenderer::DrawSkyBody (CSkyBody *pSkyBody)
{
//
// Distance factor
//
static const float fDistanceFactor = 1000.0f;
//
// Compute the position of the body
//
CVector3 vPos;
g_sRenderCtx .m_sModelToEye .PreNormalMultiply (pSkyBody ->GetNormal (), vPos);
vPos *= fDistanceFactor;
float fScale = fDistanceFactor * 16 *
pSkyBody ->GetRadius () / pSkyBody ->GetDistance ();
CVector3 vXDel (fScale, 0, 0);
CVector3 vYDel (0, fScale, 0);
//
// Draw the body as a billboard
//
CVector3 v;
glBegin (GL_QUADS);
glTexCoord2f (0, 0);
v = vPos - vXDel - vYDel;
glVertex3fv (v .m_v);
glTexCoord2f (0, 1);
v = vPos - vXDel + vYDel;
glVertex3fv (v .m_v);
glTexCoord2f (1, 1);
v = vPos + vXDel + vYDel;
glVertex3fv (v .m_v);
glTexCoord2f (1, 0);
v = vPos + vXDel - vYDel;
glVertex3fv (v .m_v);
glEnd ();
//
// Check for an error
//
CheckGlError ();
}
//-----------------------------------------------------------------------------
//
// @mfunc Draw the sky
//
// Draw the sky to the screen
//
// @rdesc None.
//
//-----------------------------------------------------------------------------
void COGLRenderer::DrawSky ()
{
CDoubleLink *pStart;
CDoubleLink *pLink;
//
// Initialize opengl. Turn on blending and disable the z buffer
//
glEnable (GL_BLEND);
glDepthMask (GL_FALSE);
//
// Map the sky dome triangles
//
g_sSkyDome .MapVertices (g_sRenderCtx .m_sModelToEye);
//
// Loop through the clouds in the sky dome and count the
// number of clouds in the system
//
int nClouds = 0;
pStart = &g_sSkyDome .m_sCloudsList;
for (pLink = pStart ->GetNext ();
pLink != pStart; pLink = pLink ->GetNext ())
{
CSkyClouds *pClouds = CSkyClouds::FromLink (pLink);
if (pClouds ->GetType () == CSkyClouds::Type_Clouds)
nClouds++;
}
//
// Loop through the clouds in the sky dome and draw the stars
//
glBlendFunc (GL_ONE, GL_ONE);
pStart = &g_sSkyDome .m_sCloudsList;
for (pLink = pStart ->GetNext ();
pLink != pStart; pLink = pLink ->GetNext ())
{
CSkyClouds *pClouds = CSkyClouds::FromLink (pLink);
if (pClouds ->GetType () != CSkyClouds::Type_Stars)
continue;
DrawSkyClouds (pClouds, pClouds ->GetCurrentColor ());
}
//
// Loop through the bodies in the sky dome
//
pStart = &g_sSkyDome .m_sBodyList;
for (pLink = pStart ->GetNext ();
pLink != pStart; pLink = pLink ->GetNext ())
{
CSkyBody *pBody = CSkyBody::FromLink (pLink);
switch (pBody ->GetType ())
{
case CSkyBody::Type_Sun:
BindTextureIndex (pBody ->GetTextureIndex ());
glBlendFunc (GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
SetColor (pBody ->GetCurrentColor ());
DrawSkyBody (pBody);
break;
case CSkyBody::Type_Moon:
BindTextureIndex (pBody ->GetMaskTextureIndex ());
glBlendFunc (GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
SetColor (g_sSkyDome .m_vCurrentSkyColor);
DrawSkyBody (pBody);
BindTextureIndex (pBody ->GetTextureIndex ());
glBlendFunc (GL_ONE, GL_ONE);
SetColor (pBody ->GetCurrentColor ());
DrawSkyBody (pBody);
break;
case CSkyBody::Type_Flare:
BindTextureIndex (pBody ->GetTextureIndex ());
glBlendFunc (GL_ONE, GL_ONE);
SetColor (pBody ->GetCurrentColor ());
DrawSkyBody (pBody);
break;
default:
_ASSERT (FALSE);
break;
}
}
//
// Compute the basic cloud color
//
CVector3 vBlendColor;
vBlendColor .m_x = 1.0 - g_sSkyDome .m_vCurrentSkyColor .m_x;
vBlendColor .m_y = 1.0 - g_sSkyDome .m_vCurrentSkyColor .m_y;
vBlendColor .m_z = 1.0 - g_sSkyDome .m_vCurrentSkyColor .m_z;
CVector3 vCloudColor (vBlendColor * (1.0f / (float) nClouds));
//
// Loop through the clouds in the sky dome rendering the clouds
//
glBlendFunc (GL_ONE, GL_ONE);
pStart = &g_sSkyDome .m_sCloudsList;
for (pLink = pStart ->GetNext ();
pLink != pStart; pLink = pLink ->GetNext ())
{
CSkyClouds *pClouds = CSkyClouds::FromLink (pLink);
if (pClouds ->GetType () != CSkyClouds::Type_Clouds)
continue;
CVector3 vColor;
DrawSkyClouds (pClouds, pClouds ->GetCurrentColor () * vCloudColor);
}
//
// Restore any changed settings
//
glDisable (GL_BLEND);
glDepthMask (GL_TRUE);
CheckGlError ();
}