gl_warp.c

来自「quake1 dos源代码最新版本」· C语言 代码 · 共 1,093 行 · 第 1/2 页

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							*pixbuf++ = blue;
							*pixbuf++ = alphabyte;
							break;
				}
			}
		}
	}
	else if (targa_header.image_type==10) {   // Runlength encoded RGB images
		unsigned char red,green,blue,alphabyte,packetHeader,packetSize,j;
		for(row=rows-1; row>=0; row--) {
			pixbuf = targa_rgba + row*columns*4;
			for(column=0; column<columns; ) {
				packetHeader=getc(fin);
				packetSize = 1 + (packetHeader & 0x7f);
				if (packetHeader & 0x80) {	// run-length packet
					switch (targa_header.pixel_size) {
						case 24:
								blue = getc(fin);
								green = getc(fin);
								red = getc(fin);
								alphabyte = 255;
								break;
						case 32:
								blue = getc(fin);
								green = getc(fin);
								red = getc(fin);
								alphabyte = getc(fin);
								break;
					}

					for(j=0;j<packetSize;j++) {
						*pixbuf++=red;
						*pixbuf++=green;
						*pixbuf++=blue;
						*pixbuf++=alphabyte;
						column++;
						if (column==columns) { // run spans across rows
							column=0;
							if (row>0)
								row--;
							else
								goto breakOut;
							pixbuf = targa_rgba + row*columns*4;
						}
					}
				}
				else {	// non run-length packet
					for(j=0;j<packetSize;j++) {
						switch (targa_header.pixel_size) {
							case 24:
									blue = getc(fin);
									green = getc(fin);
									red = getc(fin);
									*pixbuf++ = red;
									*pixbuf++ = green;
									*pixbuf++ = blue;
									*pixbuf++ = 255;
									break;
							case 32:
									blue = getc(fin);
									green = getc(fin);
									red = getc(fin);
									alphabyte = getc(fin);
									*pixbuf++ = red;
									*pixbuf++ = green;
									*pixbuf++ = blue;
									*pixbuf++ = alphabyte;
									break;
						}
						column++;
						if (column==columns) { // pixel packet run spans across rows
							column=0;
							if (row>0)
								row--;
							else
								goto breakOut;
							pixbuf = targa_rgba + row*columns*4;
						}
					}
				}
			}
			breakOut:;
		}
	}

	fclose(fin);
}

/*
==================
R_LoadSkys
==================
*/
char	*suf[6] = {"rt", "bk", "lf", "ft", "up", "dn"};
void R_LoadSkys (void)
{
	int		i;
	FILE	*f;
	char	name[64];

	for (i=0 ; i<6 ; i++)
	{
		GL_Bind (SKY_TEX + i);
		sprintf (name, "gfx/env/bkgtst%s.tga", suf[i]);
		COM_FOpenFile (name, &f, NULL);	// 2001-09-12 Returning from which searchpath a file was loaded by Maddes
		if (!f)
		{
			Con_Printf ("Couldn't load %s\n", name);
			continue;
		}
		LoadTGA (f);
//		LoadPCX (f);

		glTexImage2D (GL_TEXTURE_2D, 0, gl_solid_format, 256, 256, 0, GL_RGBA, GL_UNSIGNED_BYTE, targa_rgba);
//		glTexImage2D (GL_TEXTURE_2D, 0, gl_solid_format, 256, 256, 0, GL_RGBA, GL_UNSIGNED_BYTE, pcx_rgb);

		free (targa_rgba);
//		free (pcx_rgb);

		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	}
}


vec3_t	skyclip[6] = {
	{1,1,0},
	{1,-1,0},
	{0,-1,1},
	{0,1,1},
	{1,0,1},
	{-1,0,1}
};
int	c_sky;

// 1 = s, 2 = t, 3 = 2048
int	st_to_vec[6][3] =
{
	{3,-1,2},
	{-3,1,2},

	{1,3,2},
	{-1,-3,2},

	{-2,-1,3},		// 0 degrees yaw, look straight up
	{2,-1,-3}		// look straight down

//	{-1,2,3},
//	{1,2,-3}
};

// s = [0]/[2], t = [1]/[2]
int	vec_to_st[6][3] =
{
	{-2,3,1},
	{2,3,-1},

	{1,3,2},
	{-1,3,-2},

	{-2,-1,3},
	{-2,1,-3}

//	{-1,2,3},
//	{1,2,-3}
};

float	skymins[2][6], skymaxs[2][6];

void DrawSkyPolygon (int nump, vec3_t vecs)
{
	int		i,j;
	vec3_t	v, av;
	float	s, t, dv;
	int		axis;
	float	*vp;

	c_sky++;
#if 0
glBegin (GL_POLYGON);
for (i=0 ; i<nump ; i++, vecs+=3)
{
	VectorAdd(vecs, r_origin, v);
	glVertex3fv (v);
}
glEnd();
return;
#endif
	// decide which face it maps to
	VectorCopy (vec3_origin, v);
	for (i=0, vp=vecs ; i<nump ; i++, vp+=3)
	{
		VectorAdd (vp, v, v);
	}
	av[0] = fabs(v[0]);
	av[1] = fabs(v[1]);
	av[2] = fabs(v[2]);
	if (av[0] > av[1] && av[0] > av[2])
	{
		if (v[0] < 0)
			axis = 1;
		else
			axis = 0;
	}
	else if (av[1] > av[2] && av[1] > av[0])
	{
		if (v[1] < 0)
			axis = 3;
		else
			axis = 2;
	}
	else
	{
		if (v[2] < 0)
			axis = 5;
		else
			axis = 4;
	}

	// project new texture coords
	for (i=0 ; i<nump ; i++, vecs+=3)
	{
		j = vec_to_st[axis][2];
		if (j > 0)
			dv = vecs[j - 1];
		else
			dv = -vecs[-j - 1];

		j = vec_to_st[axis][0];
		if (j < 0)
			s = -vecs[-j -1] / dv;
		else
			s = vecs[j-1] / dv;
		j = vec_to_st[axis][1];
		if (j < 0)
			t = -vecs[-j -1] / dv;
		else
			t = vecs[j-1] / dv;

		if (s < skymins[0][axis])
			skymins[0][axis] = s;
		if (t < skymins[1][axis])
			skymins[1][axis] = t;
		if (s > skymaxs[0][axis])
			skymaxs[0][axis] = s;
		if (t > skymaxs[1][axis])
			skymaxs[1][axis] = t;
	}
}

#define	MAX_CLIP_VERTS	64
void ClipSkyPolygon (int nump, vec3_t vecs, int stage)
{
	float	*norm;
	float	*v;
	qboolean	front, back;
	float	d, e;
	float	dists[MAX_CLIP_VERTS];
	int		sides[MAX_CLIP_VERTS];
	vec3_t	newv[2][MAX_CLIP_VERTS];
	int		newc[2];
	int		i, j;

	if (nump > MAX_CLIP_VERTS-2)
		Sys_Error ("ClipSkyPolygon: MAX_CLIP_VERTS");
	if (stage == 6)
	{	// fully clipped, so draw it
		DrawSkyPolygon (nump, vecs);
		return;
	}

	front = back = false;
	norm = skyclip[stage];
	for (i=0, v = vecs ; i<nump ; i++, v+=3)
	{
		d = DotProduct (v, norm);
		if (d > ON_EPSILON)
		{
			front = true;
			sides[i] = SIDE_FRONT;
		}
		else if (d < ON_EPSILON)
		{
			back = true;
			sides[i] = SIDE_BACK;
		}
		else
			sides[i] = SIDE_ON;
		dists[i] = d;
	}

	if (!front || !back)
	{	// not clipped
		ClipSkyPolygon (nump, vecs, stage+1);
		return;
	}

	// clip it
	sides[i] = sides[0];
	dists[i] = dists[0];
	VectorCopy (vecs, (vecs+(i*3)) );
	newc[0] = newc[1] = 0;

	for (i=0, v = vecs ; i<nump ; i++, v+=3)
	{
		switch (sides[i])
		{
		case SIDE_FRONT:
			VectorCopy (v, newv[0][newc[0]]);
			newc[0]++;
			break;
		case SIDE_BACK:
			VectorCopy (v, newv[1][newc[1]]);
			newc[1]++;
			break;
		case SIDE_ON:
			VectorCopy (v, newv[0][newc[0]]);
			newc[0]++;
			VectorCopy (v, newv[1][newc[1]]);
			newc[1]++;
			break;
		}

		if (sides[i] == SIDE_ON || sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
			continue;

		d = dists[i] / (dists[i] - dists[i+1]);
		for (j=0 ; j<3 ; j++)
		{
			e = v[j] + d*(v[j+3] - v[j]);
			newv[0][newc[0]][j] = e;
			newv[1][newc[1]][j] = e;
		}
		newc[0]++;
		newc[1]++;
	}

	// continue
	ClipSkyPolygon (newc[0], newv[0][0], stage+1);
	ClipSkyPolygon (newc[1], newv[1][0], stage+1);
}

/*
=================
R_DrawSkyChain
=================
*/
void R_DrawSkyChain (msurface_t *s)
{
	msurface_t	*fa;

	int		i;
	vec3_t	verts[MAX_CLIP_VERTS];
	glpoly_t	*p;

	c_sky = 0;
	GL_Bind(solidskytexture);

	// calculate vertex values for sky box

	for (fa=s ; fa ; fa=fa->texturechain)
	{
		for (p=fa->polys ; p ; p=p->next)
		{
			for (i=0 ; i<p->numverts ; i++)
			{
				VectorSubtract (p->verts[i], r_origin, verts[i]);
			}
			ClipSkyPolygon (p->numverts, verts[0], 0);
		}
	}
}


/*
==============
R_ClearSkyBox
==============
*/
void R_ClearSkyBox (void)
{
	int		i;

	for (i=0 ; i<6 ; i++)
	{
		skymins[0][i] = skymins[1][i] = 9999;
		skymaxs[0][i] = skymaxs[1][i] = -9999;
	}
}


void MakeSkyVec (float s, float t, int axis)
{
	vec3_t		v, b;
	int			j, k;

	b[0] = s*2048;
	b[1] = t*2048;
	b[2] = 2048;

	for (j=0 ; j<3 ; j++)
	{
		k = st_to_vec[axis][j];
		if (k < 0)
			v[j] = -b[-k - 1];
		else
			v[j] = b[k - 1];
		v[j] += r_origin[j];
	}

	// avoid bilerp seam
	s = (s+1)*0.5;
	t = (t+1)*0.5;

	if (s < 1.0/512)
		s = 1.0/512;
	else if (s > 511.0/512)
		s = 511.0/512;
	if (t < 1.0/512)
		t = 1.0/512;
	else if (t > 511.0/512)
		t = 511.0/512;

	t = 1.0 - t;
	glTexCoord2f (s, t);
	glVertex3fv (v);
}

/*
==============
R_DrawSkyBox
==============
*/
int	skytexorder[6] = {0,2,1,3,4,5};
void R_DrawSkyBox (void)
{
	int		i, j, k;
	vec3_t	v;
	float	s, t;

#if 0
glEnable (GL_BLEND);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glColor4f (1,1,1,0.5);
glDisable (GL_DEPTH_TEST);
#endif
	for (i=0 ; i<6 ; i++)
	{
		if (skymins[0][i] >= skymaxs[0][i]
		|| skymins[1][i] >= skymaxs[1][i])
			continue;

		GL_Bind (SKY_TEX+skytexorder[i]);
#if 0
skymins[0][i] = -1;
skymins[1][i] = -1;
skymaxs[0][i] = 1;
skymaxs[1][i] = 1;
#endif
		glBegin (GL_QUADS);
		MakeSkyVec (skymins[0][i], skymins[1][i], i);
		MakeSkyVec (skymins[0][i], skymaxs[1][i], i);
		MakeSkyVec (skymaxs[0][i], skymaxs[1][i], i);
		MakeSkyVec (skymaxs[0][i], skymins[1][i], i);
		glEnd ();
	}
#if 0
glDisable (GL_BLEND);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glColor4f (1,1,1,0.5);
glEnable (GL_DEPTH_TEST);
#endif
}


#endif

//===============================================================

/*
=============
R_InitSky

A sky texture is 256*128, with the right side being a masked overlay
==============
*/
void R_InitSky (texture_t *mt)
{
	int			i, j, p;
	byte		*src;
	unsigned	trans[128*128];
	unsigned	transpix;
	int			r, g, b;
	unsigned	*rgba;
	extern	int			skytexturenum;

	src = (byte *)mt + mt->offsets[0];

	// make an average value for the back to avoid
	// a fringe on the top level

	r = g = b = 0;
	for (i=0 ; i<128 ; i++)
		for (j=0 ; j<128 ; j++)
		{
			p = src[i*256 + j + 128];
			rgba = &d_8to24table[p];
			trans[(i*128) + j] = *rgba;
			r += ((byte *)rgba)[0];
			g += ((byte *)rgba)[1];
			b += ((byte *)rgba)[2];
		}

	((byte *)&transpix)[0] = r/(128*128);
	((byte *)&transpix)[1] = g/(128*128);
	((byte *)&transpix)[2] = b/(128*128);
	((byte *)&transpix)[3] = 0;


	if (!solidskytexture)
		solidskytexture = texture_extension_number++;
	GL_Bind (solidskytexture );
	glTexImage2D (GL_TEXTURE_2D, 0, gl_solid_format, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, trans);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);


	for (i=0 ; i<128 ; i++)
		for (j=0 ; j<128 ; j++)
		{
			p = src[i*256 + j];
			if (p == 0)
				trans[(i*128) + j] = transpix;
			else
				trans[(i*128) + j] = d_8to24table[p];
		}

	if (!alphaskytexture)
		alphaskytexture = texture_extension_number++;
	GL_Bind(alphaskytexture);
	glTexImage2D (GL_TEXTURE_2D, 0, gl_alpha_format, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, trans);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}

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