pb.h

Go to the documentation of this file.

/* $Id: pb.h,v 1.4 1997/11/13 02:16:48 brianp Exp $ */

/*
 * Mesa 3-D graphics library
 * Version:  2.5
 * Copyright (C) 1995-1997  Brian Paul
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


/*
 * $Log: pb.h,v $
 * Revision 1.4  1997/11/13 02:16:48  brianp
 * added lambda array, initialized to zeros
 *
 * Revision 1.3  1997/05/09 22:40:19  brianp
 * added gl_alloc_pb()
 *
 * Revision 1.2  1997/02/09 18:43:14  brianp
 * added GL_EXT_texture3D support
 *
 * Revision 1.1  1996/09/13 01:38:16  brianp
 * Initial revision
 *
 */


#ifndef PB_H
#define PB_H


#include "types.h"



/*
 * Pixel buffer size, must be larger than MAX_WIDTH.
 */
#define PB_SIZE (3*MAX_WIDTH)


struct pixel_buffer {
    GLint x[PB_SIZE];   /* X window coord in [0,MAX_WIDTH) */
    GLint y[PB_SIZE];   /* Y window coord in [0,MAX_HEIGHT) */
    GLdepth z[PB_SIZE]; /* Z window coord in [0,MAX_DEPTH] */
    GLubyte r[PB_SIZE]; /* Red */
    GLubyte g[PB_SIZE]; /* Green */
    GLubyte b[PB_SIZE]; /* Blue */
    GLubyte a[PB_SIZE]; /* Alpha */
    GLuint i[PB_SIZE];  /* Index */
    GLfloat s[PB_SIZE]; /* Texture S coordinate */
    GLfloat t[PB_SIZE]; /* Texture T coordinate */
    GLfloat u[PB_SIZE]; /* Texture R coordinate */
    GLfloat lambda[PB_SIZE];/* Texture lambda value */
    GLint color[4];     /* Mono color, integers! */
    GLuint index;       /* Mono index */
    GLuint count;       /* Number of pixels in buffer */
    GLboolean mono;     /* Same color or index for all pixels? */
    GLenum primitive;   /* GL_POINT, GL_LINE, GL_POLYGON or GL_BITMAP*/
};


/*
 * Initialize the Pixel Buffer, specifying the type of primitive being drawn.
 */
#define PB_INIT( PB, PRIM )     \
    (PB)->count = 0;        \
    (PB)->mono = GL_FALSE;      \
    (PB)->primitive = (PRIM);



/*
 * Set the color used for all subsequent pixels in the buffer.
 */
#define PB_SET_COLOR( CTX, PB, R, G, B, A )     \
    if ((PB)->color[0]!=(R) || (PB)->color[1]!=(G)  \
     || (PB)->color[2]!=(B) || (PB)->color[3]!=(A)  \
     || !(PB)->mono) {              \
        gl_flush_pb( ctx );         \
    }                       \
    (PB)->color[0] = R;             \
    (PB)->color[1] = G;             \
    (PB)->color[2] = B;             \
    (PB)->color[3] = A;             \
    (PB)->mono = GL_TRUE;


/*
 * Set the color index used for all subsequent pixels in the buffer.
 */
#define PB_SET_INDEX( CTX, PB, I )      \
    if ((PB)->index!=(I) || !(PB)->mono) {  \
        gl_flush_pb( CTX );     \
    }                   \
    (PB)->index = I;            \
    (PB)->mono = GL_TRUE;


/*
 * "write" a pixel using current color or index
 */
#define PB_WRITE_PIXEL( PB, X, Y, Z )       \
    (PB)->x[(PB)->count] = X;       \
    (PB)->y[(PB)->count] = Y;       \
    (PB)->z[(PB)->count] = Z;       \
    (PB)->count++;


/*
 * "write" an RGBA pixel
 */
#define PB_WRITE_RGBA_PIXEL( PB, X, Y, Z, R, G, B, A )  \
    (PB)->x[(PB)->count] = X;           \
    (PB)->y[(PB)->count] = Y;           \
    (PB)->z[(PB)->count] = Z;           \
    (PB)->r[(PB)->count] = R;           \
    (PB)->g[(PB)->count] = G;           \
    (PB)->b[(PB)->count] = B;           \
    (PB)->a[(PB)->count] = A;           \
    (PB)->count++;

/*
 * "write" a color-index pixel
 */
#define PB_WRITE_CI_PIXEL( PB, X, Y, Z, I ) \
    (PB)->x[(PB)->count] = X;       \
    (PB)->y[(PB)->count] = Y;       \
    (PB)->z[(PB)->count] = Z;       \
    (PB)->i[(PB)->count] = I;       \
    (PB)->count++;


/*
 * "write" an RGBA pixel with texture coordinates
 */
#define PB_WRITE_TEX_PIXEL( PB, X, Y, Z, R, G, B, A, S, T, U )  \
    (PB)->x[(PB)->count] = X;               \
    (PB)->y[(PB)->count] = Y;               \
    (PB)->z[(PB)->count] = Z;               \
    (PB)->r[(PB)->count] = R;               \
    (PB)->g[(PB)->count] = G;               \
    (PB)->b[(PB)->count] = B;               \
    (PB)->a[(PB)->count] = A;               \
    (PB)->s[(PB)->count] = S;               \
    (PB)->t[(PB)->count] = T;               \
    (PB)->u[(PB)->count] = U;               \
    (PB)->count++;


/*
 * Call this function at least every MAX_WIDTH pixels:
 */
#define PB_CHECK_FLUSH( CTX, PB )       \
    if ((PB)->count>=PB_SIZE-MAX_WIDTH) {   \
       gl_flush_pb( CTX );          \
    }


extern struct pixel_buffer *gl_alloc_pb(void);

extern void gl_flush_pb( GLcontext *ctx );

#endif