gl_rsurf.c

Quake 2 Source code for students by Theerthan You can also download from idsoftwares.com

/*
Copyright (C) 1997-2001 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// GL_RSURF.C: surface-related refresh code
#include <assert.h>

#include "gl_local.h"

static vec3_t	modelorg;		// relative to viewpoint

msurface_t	*r_alpha_surfaces;

#define DYNAMIC_LIGHT_WIDTH  128
#define DYNAMIC_LIGHT_HEIGHT 128

#define LIGHTMAP_BYTES 4

#define	BLOCK_WIDTH		128
#define	BLOCK_HEIGHT	128

#define	MAX_LIGHTMAPS	128

int		c_visible_lightmaps;
int		c_visible_textures;

#define GL_LIGHTMAP_FORMAT GL_RGBA

typedef struct
{
	int internal_format;
	int	current_lightmap_texture;

	msurface_t	*lightmap_surfaces[MAX_LIGHTMAPS];

	int			allocated[BLOCK_WIDTH];

	// the lightmap texture data needs to be kept in
	// main memory so texsubimage can update properly
	byte		lightmap_buffer[4*BLOCK_WIDTH*BLOCK_HEIGHT];
} gllightmapstate_t;

static gllightmapstate_t gl_lms;


static void		LM_InitBlock( void );
static void		LM_UploadBlock( qboolean dynamic );
static qboolean	LM_AllocBlock (int w, int h, int *x, int *y);

extern void R_SetCacheState( msurface_t *surf );
extern void R_BuildLightMap (msurface_t *surf, byte *dest, int stride);

/*
=============================================================

	BRUSH MODELS

=============================================================
*/

/*
===============
R_TextureAnimation

Returns the proper texture for a given time and base texture
===============
*/
image_t *R_TextureAnimation (mtexinfo_t *tex)
{
	int		c;

	if (!tex->next)
		return tex->image;

	c = currententity->frame % tex->numframes;
	while (c)
	{
		tex = tex->next;
		c--;
	}

	return tex->image;
}

#if 0
/*
=================
WaterWarpPolyVerts

Mangles the x and y coordinates in a copy of the poly
so that any drawing routine can be water warped
=================
*/
glpoly_t *WaterWarpPolyVerts (glpoly_t *p)
{
	int		i;
	float	*v, *nv;
	static byte	buffer[1024];
	glpoly_t *out;

	out = (glpoly_t *)buffer;

	out->numverts = p->numverts;
	v = p->verts[0];
	nv = out->verts[0];
	for (i=0 ; i<p->numverts ; i++, v+= VERTEXSIZE, nv+=VERTEXSIZE)
	{
		nv[0] = v[0] + 4*sin(v[1]*0.05+r_newrefdef.time)*sin(v[2]*0.05+r_newrefdef.time);
		nv[1] = v[1] + 4*sin(v[0]*0.05+r_newrefdef.time)*sin(v[2]*0.05+r_newrefdef.time);

		nv[2] = v[2];
		nv[3] = v[3];
		nv[4] = v[4];
		nv[5] = v[5];
		nv[6] = v[6];
	}

	return out;
}

/*
================
DrawGLWaterPoly

Warp the vertex coordinates
================
*/
void DrawGLWaterPoly (glpoly_t *p)
{
	int		i;
	float	*v;

	p = WaterWarpPolyVerts (p);
	qglBegin (GL_TRIANGLE_FAN);
	v = p->verts[0];
	for (i=0 ; i<p->numverts ; i++, v+= VERTEXSIZE)
	{
		qglTexCoord2f (v[3], v[4]);
		qglVertex3fv (v);
	}
	qglEnd ();
}
void DrawGLWaterPolyLightmap (glpoly_t *p)
{
	int		i;
	float	*v;

	p = WaterWarpPolyVerts (p);
	qglBegin (GL_TRIANGLE_FAN);
	v = p->verts[0];
	for (i=0 ; i<p->numverts ; i++, v+= VERTEXSIZE)
	{
		qglTexCoord2f (v[5], v[6]);
		qglVertex3fv (v);
	}
	qglEnd ();
}
#endif

/*
================
DrawGLPoly
================
*/
void DrawGLPoly (glpoly_t *p)
{
	int		i;
	float	*v;

	qglBegin (GL_POLYGON);
	v = p->verts[0];
	for (i=0 ; i<p->numverts ; i++, v+= VERTEXSIZE)
	{
		qglTexCoord2f (v[3], v[4]);
		qglVertex3fv (v);
	}
	qglEnd ();
}

//============
//PGM
/*
================
DrawGLFlowingPoly -- version of DrawGLPoly that handles scrolling texture
================
*/
void DrawGLFlowingPoly (msurface_t *fa)
{
	int		i;
	float	*v;
	glpoly_t *p;
	float	scroll;

	p = fa->polys;

	scroll = -64 * ( (r_newrefdef.time / 40.0) - (int)(r_newrefdef.time / 40.0) );
	if(scroll == 0.0)
		scroll = -64.0;

	qglBegin (GL_POLYGON);
	v = p->verts[0];
	for (i=0 ; i<p->numverts ; i++, v+= VERTEXSIZE)
	{
		qglTexCoord2f ((v[3] + scroll), v[4]);
		qglVertex3fv (v);
	}
	qglEnd ();
}
//PGM
//============

/*
** R_DrawTriangleOutlines
*/
void R_DrawTriangleOutlines (void)
{
	int			i, j;
	glpoly_t	*p;

	if (!gl_showtris->value)
		return;

	qglDisable (GL_TEXTURE_2D);
	qglDisable (GL_DEPTH_TEST);
	qglColor4f (1,1,1,1);

	for (i=0 ; i<MAX_LIGHTMAPS ; i++)
	{
		msurface_t *surf;

		for ( surf = gl_lms.lightmap_surfaces[i]; surf != 0; surf = surf->lightmapchain )
		{
			p = surf->polys;
			for ( ; p ; p=p->chain)
			{
				for (j=2 ; j<p->numverts ; j++ )
				{
					qglBegin (GL_LINE_STRIP);
					qglVertex3fv (p->verts[0]);
					qglVertex3fv (p->verts[j-1]);
					qglVertex3fv (p->verts[j]);
					qglVertex3fv (p->verts[0]);
					qglEnd ();
				}
			}
		}
	}

	qglEnable (GL_DEPTH_TEST);
	qglEnable (GL_TEXTURE_2D);
}

/*
** DrawGLPolyChain
*/
void DrawGLPolyChain( glpoly_t *p, float soffset, float toffset )
{
	if ( soffset == 0 && toffset == 0 )
	{
		for ( ; p != 0; p = p->chain )
		{
			float *v;
			int j;

			qglBegin (GL_POLYGON);
			v = p->verts[0];
			for (j=0 ; j<p->numverts ; j++, v+= VERTEXSIZE)
			{
				qglTexCoord2f (v[5], v[6] );
				qglVertex3fv (v);
			}
			qglEnd ();
		}
	}
	else
	{
		for ( ; p != 0; p = p->chain )
		{
			float *v;
			int j;

			qglBegin (GL_POLYGON);
			v = p->verts[0];
			for (j=0 ; j<p->numverts ; j++, v+= VERTEXSIZE)
			{
				qglTexCoord2f (v[5] - soffset, v[6] - toffset );
				qglVertex3fv (v);
			}
			qglEnd ();
		}
	}
}

/*
** R_BlendLightMaps
**
** This routine takes all the given light mapped surfaces in the world and
** blends them into the framebuffer.
*/
void R_BlendLightmaps (void)
{
	int			i;
	msurface_t	*surf, *newdrawsurf = 0;

	// don't bother if we're set to fullbright
	if (r_fullbright->value)
		return;
	if (!r_worldmodel->lightdata)
		return;

	// don't bother writing Z
	qglDepthMask( 0 );

	/*
	** set the appropriate blending mode unless we're only looking at the
	** lightmaps.
	*/
	if (!gl_lightmap->value)
	{
		qglEnable (GL_BLEND);

		if ( gl_saturatelighting->value )
		{
			qglBlendFunc( GL_ONE, GL_ONE );
		}
		else
		{
			if ( gl_monolightmap->string[0] != '0' )
			{
				switch ( toupper( gl_monolightmap->string[0] ) )
				{
				case 'I':
					qglBlendFunc (GL_ZERO, GL_SRC_COLOR );
					break;
				case 'L':
					qglBlendFunc (GL_ZERO, GL_SRC_COLOR );
					break;
				case 'A':
				default:
					qglBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
					break;
				}
			}
			else
			{
				qglBlendFunc (GL_ZERO, GL_SRC_COLOR );
			}
		}
	}

	if ( currentmodel == r_worldmodel )
		c_visible_lightmaps = 0;

	/*
	** render static lightmaps first
	*/
	for ( i = 1; i < MAX_LIGHTMAPS; i++ )
	{
		if ( gl_lms.lightmap_surfaces[i] )
		{
			if (currentmodel == r_worldmodel)
				c_visible_lightmaps++;
			GL_Bind( gl_state.lightmap_textures + i);

			for ( surf = gl_lms.lightmap_surfaces[i]; surf != 0; surf = surf->lightmapchain )
			{
				if ( surf->polys )
					DrawGLPolyChain( surf->polys, 0, 0 );
			}
		}
	}

	/*
	** render dynamic lightmaps
	*/
	if ( gl_dynamic->value )
	{
		LM_InitBlock();

		GL_Bind( gl_state.lightmap_textures+0 );

		if (currentmodel == r_worldmodel)
			c_visible_lightmaps++;

		newdrawsurf = gl_lms.lightmap_surfaces[0];

		for ( surf = gl_lms.lightmap_surfaces[0]; surf != 0; surf = surf->lightmapchain )
		{
			int		smax, tmax;
			byte	*base;

			smax = (surf->extents[0]>>4)+1;
			tmax = (surf->extents[1]>>4)+1;

			if ( LM_AllocBlock( smax, tmax, &surf->dlight_s, &surf->dlight_t ) )
			{
				base = gl_lms.lightmap_buffer;
				base += ( surf->dlight_t * BLOCK_WIDTH + surf->dlight_s ) * LIGHTMAP_BYTES;

				R_BuildLightMap (surf, base, BLOCK_WIDTH*LIGHTMAP_BYTES);
			}
			else
			{
				msurface_t *drawsurf;

				// upload what we have so far
				LM_UploadBlock( true );

				// draw all surfaces that use this lightmap
				for ( drawsurf = newdrawsurf; drawsurf != surf; drawsurf = drawsurf->lightmapchain )
				{
					if ( drawsurf->polys )
						DrawGLPolyChain( drawsurf->polys, 
							              ( drawsurf->light_s - drawsurf->dlight_s ) * ( 1.0 / 128.0 ), 
										( drawsurf->light_t - drawsurf->dlight_t ) * ( 1.0 / 128.0 ) );
				}

				newdrawsurf = drawsurf;

				// clear the block
				LM_InitBlock();

				// try uploading the block now
				if ( !LM_AllocBlock( smax, tmax, &surf->dlight_s, &surf->dlight_t ) )
				{
					ri.Sys_Error( ERR_FATAL, "Consecutive calls to LM_AllocBlock(%d,%d) failed (dynamic)\n", smax, tmax );
				}

				base = gl_lms.lightmap_buffer;
				base += ( surf->dlight_t * BLOCK_WIDTH + surf->dlight_s ) * LIGHTMAP_BYTES;

				R_BuildLightMap (surf, base, BLOCK_WIDTH*LIGHTMAP_BYTES);
			}
		}

		/*
		** draw remainder of dynamic lightmaps that haven't been uploaded yet
		*/
		if ( newdrawsurf )
			LM_UploadBlock( true );

		for ( surf = newdrawsurf; surf != 0; surf = surf->lightmapchain )
		{
			if ( surf->polys )
				DrawGLPolyChain( surf->polys, ( surf->light_s - surf->dlight_s ) * ( 1.0 / 128.0 ), ( surf->light_t - surf->dlight_t ) * ( 1.0 / 128.0 ) );
		}
	}

	/*
	** restore state
	*/
	qglDisable (GL_BLEND);
	qglBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	qglDepthMask( 1 );
}

/*
================
R_RenderBrushPoly
================
*/
void R_RenderBrushPoly (msurface_t *fa)
{
	int			maps;
	image_t		*image;
	qboolean is_dynamic = false;

	c_brush_polys++;

	image = R_TextureAnimation (fa->texinfo);

	if (fa->flags & SURF_DRAWTURB)
	{	
		GL_Bind( image->texnum );

		// warp texture, no lightmaps
		GL_TexEnv( GL_MODULATE );
		qglColor4f( gl_state.inverse_intensity, 
			        gl_state.inverse_intensity,
					gl_state.inverse_intensity,
					1.0F );
		EmitWaterPolys (fa);
		GL_TexEnv( GL_REPLACE );

		return;
	}
	else
	{
		GL_Bind( image->texnum );

		GL_TexEnv( GL_REPLACE );
	}

//======
//PGM
	if(fa->texinfo->flags & SURF_FLOWING)
		DrawGLFlowingPoly (fa);
	else
		DrawGLPoly (fa->polys);
//PGM
//======

	/*
	** check for lightmap modification
	*/
	for ( maps = 0; maps < MAXLIGHTMAPS && fa->styles[maps] != 255; maps++ )
	{
		if ( r_newrefdef.lightstyles[fa->styles[maps]].white != fa->cached_light[maps] )
			goto dynamic;
	}

	// dynamic this frame or dynamic previously
	if ( ( fa->dlightframe == r_framecount ) )
	{
dynamic:
		if ( gl_dynamic->value )
		{
			if (!( fa->texinfo->flags & (SURF_SKY|SURF_TRANS33|SURF_TRANS66|SURF_WARP ) ) )
			{
				is_dynamic = true;
			}
		}
	}

	if ( is_dynamic )
	{
		if ( ( fa->styles[maps] >= 32 || fa->styles[maps] == 0 ) && ( fa->dlightframe != r_framecount ) )
		{
			unsigned	temp[34*34];
			int			smax, tmax;

			smax = (fa->extents[0]>>4)+1;
			tmax = (fa->extents[1]>>4)+1;

			R_BuildLightMap( fa, (void *)temp, smax*4 );
			R_SetCacheState( fa );

			GL_Bind( gl_state.lightmap_textures + fa->lightmaptexturenum );

			qglTexSubImage2D( GL_TEXTURE_2D, 0,