mirror of
https://github.com/reactos/reactos.git
synced 2024-08-28 14:18:41 +00:00
930 lines
26 KiB
C
930 lines
26 KiB
C
![]() |
/* $Id: span.c,v 1.12 1997/08/14 01:12:37 brianp Exp $ */
|
||
|
|
||
|
/*
|
||
|
* Mesa 3-D graphics library
|
||
|
* Version: 2.4
|
||
|
* 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: span.c,v $
|
||
|
* Revision 1.12 1997/08/14 01:12:37 brianp
|
||
|
* replaced a few for loops with MEMSET calls
|
||
|
*
|
||
|
* Revision 1.11 1997/07/24 01:21:56 brianp
|
||
|
* changed precompiled header symbol from PCH to PC_HEADER
|
||
|
*
|
||
|
* Revision 1.10 1997/05/28 03:26:29 brianp
|
||
|
* added precompiled header (PCH) support
|
||
|
*
|
||
|
* Revision 1.9 1997/05/03 00:51:30 brianp
|
||
|
* new texturing function call: gl_texture_pixels()
|
||
|
*
|
||
|
* Revision 1.8 1997/04/16 23:54:11 brianp
|
||
|
* do per-pixel fog if texturing is enabled
|
||
|
*
|
||
|
* Revision 1.7 1997/02/09 19:53:43 brianp
|
||
|
* now use TEXTURE_xD enable constants
|
||
|
*
|
||
|
* Revision 1.6 1997/02/09 18:43:34 brianp
|
||
|
* added GL_EXT_texture3D support
|
||
|
*
|
||
|
* Revision 1.5 1997/01/28 22:17:44 brianp
|
||
|
* new RGBA mode logic op support
|
||
|
*
|
||
|
* Revision 1.4 1996/09/25 03:22:05 brianp
|
||
|
* added NO_DRAW_BIT support
|
||
|
*
|
||
|
* Revision 1.3 1996/09/15 14:18:55 brianp
|
||
|
* now use GLframebuffer and GLvisual
|
||
|
*
|
||
|
* Revision 1.2 1996/09/15 01:48:58 brianp
|
||
|
* removed #define NULL 0
|
||
|
*
|
||
|
* Revision 1.1 1996/09/13 01:38:16 brianp
|
||
|
* Initial revision
|
||
|
*
|
||
|
*/
|
||
|
|
||
|
|
||
|
/*
|
||
|
* pixel span rasterization:
|
||
|
* These functions simulate the rasterization pipeline.
|
||
|
*/
|
||
|
|
||
|
|
||
|
#ifdef PC_HEADER
|
||
|
#include "all.h"
|
||
|
#else
|
||
|
#include <string.h>
|
||
|
#include "alpha.h"
|
||
|
#include "alphabuf.h"
|
||
|
#include "blend.h"
|
||
|
#include "depth.h"
|
||
|
#include "fog.h"
|
||
|
#include "logic.h"
|
||
|
#include "macros.h"
|
||
|
#include "masking.h"
|
||
|
#include "scissor.h"
|
||
|
#include "span.h"
|
||
|
#include "stencil.h"
|
||
|
#include "texture.h"
|
||
|
#include "types.h"
|
||
|
#endif
|
||
|
|
||
|
|
||
|
|
||
|
|
||
|
/*
|
||
|
* Apply the current polygon stipple pattern to a span of pixels.
|
||
|
*/
|
||
|
static void stipple_polygon_span( GLcontext *ctx,
|
||
|
GLuint n, GLint x, GLint y, GLubyte mask[] )
|
||
|
{
|
||
|
register GLuint i, m, stipple, highbit=0x80000000;
|
||
|
|
||
|
stipple = ctx->PolygonStipple[y % 32];
|
||
|
m = highbit >> (GLuint) (x % 32);
|
||
|
|
||
|
for (i=0;i<n;i++) {
|
||
|
if ((m & stipple)==0) {
|
||
|
mask[i] = 0;
|
||
|
}
|
||
|
m = m >> 1;
|
||
|
if (m==0) {
|
||
|
m = 0x80000000;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
|
||
|
/*
|
||
|
* Clip a pixel span to the current buffer/window boundaries.
|
||
|
* Return: 0 = all pixels clipped
|
||
|
* 1 = at least one pixel is visible
|
||
|
*/
|
||
|
static GLuint clip_span( GLcontext *ctx,
|
||
|
GLint n, GLint x, GLint y, GLubyte mask[] )
|
||
|
{
|
||
|
GLint i;
|
||
|
|
||
|
/* Clip to top and bottom */
|
||
|
if (y<0 || y>=ctx->Buffer->Height) {
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* Clip to left and right */
|
||
|
if (x>=0 && x+n<=ctx->Buffer->Width) {
|
||
|
/* no clipping needed */
|
||
|
return 1;
|
||
|
}
|
||
|
else if (x+n<=0) {
|
||
|
/* completely off left side */
|
||
|
return 0;
|
||
|
}
|
||
|
else if (x>=ctx->Buffer->Width) {
|
||
|
/* completely off right side */
|
||
|
return 0;
|
||
|
}
|
||
|
else {
|
||
|
/* clip-test each pixel, this could be done better */
|
||
|
for (i=0;i<n;i++) {
|
||
|
if (x+i<0 || x+i>=ctx->Buffer->Width) {
|
||
|
mask[i] = 0;
|
||
|
}
|
||
|
}
|
||
|
return 1;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
|
||
|
/*
|
||
|
* Write a horizontal span of color index pixels to the frame buffer.
|
||
|
* Stenciling, Depth-testing, etc. are done as needed.
|
||
|
* Input: n - number of pixels in the span
|
||
|
* x, y - location of leftmost pixel in the span
|
||
|
* z - array of [n] z-values
|
||
|
* index - array of [n] color indexes
|
||
|
* primitive - either GL_POINT, GL_LINE, GL_POLYGON, or GL_BITMAP
|
||
|
*/
|
||
|
void gl_write_index_span( GLcontext *ctx,
|
||
|
GLuint n, GLint x, GLint y, GLdepth z[],
|
||
|
GLuint index[], GLenum primitive )
|
||
|
{
|
||
|
GLubyte mask[MAX_WIDTH];
|
||
|
GLuint index_save[MAX_WIDTH];
|
||
|
|
||
|
/* init mask to 1's (all pixels are to be written) */
|
||
|
MEMSET(mask, 1, n);
|
||
|
|
||
|
if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
|
||
|
if (clip_span(ctx,n,x,y,mask)==0) {
|
||
|
return;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Per-pixel fog */
|
||
|
if (ctx->Fog.Enabled
|
||
|
&& (ctx->Hint.Fog==GL_NICEST || primitive==GL_BITMAP)) {
|
||
|
gl_fog_index_pixels( ctx, n, z, index );
|
||
|
}
|
||
|
|
||
|
/* Do the scissor test */
|
||
|
if (ctx->Scissor.Enabled) {
|
||
|
if (gl_scissor_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Polygon Stippling */
|
||
|
if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
|
||
|
stipple_polygon_span( ctx, n, x, y, mask );
|
||
|
}
|
||
|
|
||
|
if (ctx->Stencil.Enabled) {
|
||
|
/* first stencil test */
|
||
|
if (gl_stencil_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
/* depth buffering w/ stencil */
|
||
|
gl_depth_stencil_span( ctx, n, x, y, z, mask );
|
||
|
}
|
||
|
else if (ctx->Depth.Test) {
|
||
|
/* regular depth testing */
|
||
|
if ((*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask )==0) return;
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & NO_DRAW_BIT) {
|
||
|
/* write no pixels */
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT) {
|
||
|
/* Save a copy of the indexes since LogicOp and IndexMask
|
||
|
* may change them
|
||
|
*/
|
||
|
MEMCPY( index_save, index, n * sizeof(GLuint) );
|
||
|
}
|
||
|
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_ci_span( ctx, n, x, y, index, mask );
|
||
|
}
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_index_span( ctx, n, x, y, index );
|
||
|
}
|
||
|
|
||
|
/* write pixels */
|
||
|
(*ctx->Driver.WriteIndexSpan)( ctx, n, x, y, index, mask );
|
||
|
|
||
|
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT) {
|
||
|
/*** Also draw to back buffer ***/
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_BACK );
|
||
|
MEMCPY( index, index_save, n * sizeof(GLuint) );
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_ci_span( ctx, n, x, y, index, mask );
|
||
|
}
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_index_span( ctx, n, x, y, index );
|
||
|
}
|
||
|
(*ctx->Driver.WriteIndexSpan)( ctx, n, x, y, index, mask );
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_FRONT );
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
|
||
|
|
||
|
void gl_write_monoindex_span( GLcontext *ctx,
|
||
|
GLuint n, GLint x, GLint y, GLdepth z[],
|
||
|
GLuint index, GLenum primitive )
|
||
|
{
|
||
|
GLuint i;
|
||
|
GLubyte mask[MAX_WIDTH];
|
||
|
GLuint index_save[MAX_WIDTH];
|
||
|
|
||
|
/* init mask to 1's (all pixels are to be written) */
|
||
|
MEMSET(mask, 1, n);
|
||
|
|
||
|
if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP)
|
||
|
{
|
||
|
if (clip_span( ctx,n,x,y,mask)==0) {
|
||
|
return;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Do the scissor test */
|
||
|
if (ctx->Scissor.Enabled)
|
||
|
{
|
||
|
if (gl_scissor_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Polygon Stippling */
|
||
|
if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON)
|
||
|
{
|
||
|
stipple_polygon_span( ctx, n, x, y, mask );
|
||
|
}
|
||
|
|
||
|
if (ctx->Stencil.Enabled)
|
||
|
{
|
||
|
/* first stencil test */
|
||
|
if (gl_stencil_span( ctx, n, x, y, mask )==0)
|
||
|
{
|
||
|
return;
|
||
|
}
|
||
|
/* depth buffering w/ stencil */
|
||
|
gl_depth_stencil_span( ctx, n, x, y, z, mask );
|
||
|
}
|
||
|
else if (ctx->Depth.Test)
|
||
|
{
|
||
|
/* regular depth testing */
|
||
|
if ((*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask )==0)
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & NO_DRAW_BIT)
|
||
|
{
|
||
|
/* write no pixels */
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if ((ctx->Fog.Enabled && (ctx->Hint.Fog==GL_NICEST || primitive==GL_BITMAP))
|
||
|
|| ctx->Color.SWLogicOpEnabled || ctx->Color.SWmasking)
|
||
|
{
|
||
|
GLuint ispan[MAX_WIDTH];
|
||
|
/* index may change, replicate single index into an array */
|
||
|
for (i=0;i<n;i++)
|
||
|
{
|
||
|
ispan[i] = index;
|
||
|
}
|
||
|
|
||
|
if (ctx->Fog.Enabled
|
||
|
&& (ctx->Hint.Fog==GL_NICEST || primitive==GL_BITMAP))
|
||
|
{
|
||
|
gl_fog_index_pixels( ctx, n, z, ispan );
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT)
|
||
|
{
|
||
|
MEMCPY( index_save, ispan, n * sizeof(GLuint) );
|
||
|
}
|
||
|
|
||
|
if (ctx->Color.SWLogicOpEnabled)
|
||
|
{
|
||
|
gl_logicop_ci_span( ctx, n, x, y, ispan, mask );
|
||
|
}
|
||
|
|
||
|
if (ctx->Color.SWmasking)
|
||
|
{
|
||
|
gl_mask_index_span( ctx, n, x, y, ispan );
|
||
|
}
|
||
|
|
||
|
(*ctx->Driver.WriteIndexSpan)( ctx, n, x, y, ispan, mask );
|
||
|
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT)
|
||
|
{
|
||
|
/*** Also draw to back buffer ***/
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_BACK );
|
||
|
for (i=0;i<n;i++)
|
||
|
{
|
||
|
ispan[i] = index;
|
||
|
}
|
||
|
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_ci_span( ctx, n, x, y, ispan, mask );
|
||
|
}
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_index_span( ctx, n, x, y, ispan );
|
||
|
}
|
||
|
(*ctx->Driver.WriteIndexSpan)( ctx, n, x, y, ispan, mask );
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_FRONT );
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
(*ctx->Driver.WriteMonoindexSpan)( ctx, n, x, y, mask );
|
||
|
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT)
|
||
|
{
|
||
|
/*** Also draw to back buffer ***/
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_BACK );
|
||
|
(*ctx->Driver.WriteMonoindexSpan)( ctx, n, x, y, mask );
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_FRONT );
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
|
||
|
void gl_write_color_span( GLcontext *ctx,
|
||
|
GLuint n, GLint x, GLint y, GLdepth z[],
|
||
|
GLubyte r[], GLubyte g[],
|
||
|
GLubyte b[], GLubyte a[],
|
||
|
GLenum primitive )
|
||
|
{
|
||
|
GLubyte mask[MAX_WIDTH];
|
||
|
GLboolean write_all = GL_TRUE;
|
||
|
GLubyte rtmp[MAX_WIDTH], gtmp[MAX_WIDTH], btmp[MAX_WIDTH], atmp[MAX_WIDTH];
|
||
|
GLubyte *red, *green, *blue, *alpha;
|
||
|
|
||
|
/* init mask to 1's (all pixels are to be written) */
|
||
|
MEMSET(mask, 1, n);
|
||
|
|
||
|
if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
|
||
|
if (clip_span( ctx,n,x,y,mask)==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
if ((primitive==GL_BITMAP && ctx->MutablePixels)
|
||
|
|| (ctx->RasterMask & FRONT_AND_BACK_BIT)) {
|
||
|
/* must make a copy of the colors since they may be modified */
|
||
|
MEMCPY( rtmp, r, n * sizeof(GLubyte) );
|
||
|
MEMCPY( gtmp, g, n * sizeof(GLubyte) );
|
||
|
MEMCPY( btmp, b, n * sizeof(GLubyte) );
|
||
|
MEMCPY( atmp, a, n * sizeof(GLubyte) );
|
||
|
red = rtmp;
|
||
|
green = gtmp;
|
||
|
blue = btmp;
|
||
|
alpha = atmp;
|
||
|
}
|
||
|
else {
|
||
|
red = r;
|
||
|
green = g;
|
||
|
blue = b;
|
||
|
alpha = a;
|
||
|
}
|
||
|
|
||
|
/* Per-pixel fog */
|
||
|
if (ctx->Fog.Enabled && (ctx->Hint.Fog==GL_NICEST || primitive==GL_BITMAP
|
||
|
|| ctx->Texture.Enabled)) {
|
||
|
gl_fog_color_pixels( ctx, n, z, red, green, blue, alpha );
|
||
|
}
|
||
|
|
||
|
/* Do the scissor test */
|
||
|
if (ctx->Scissor.Enabled) {
|
||
|
if (gl_scissor_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
/* Polygon Stippling */
|
||
|
if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
|
||
|
stipple_polygon_span( ctx, n, x, y, mask );
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
/* Do the alpha test */
|
||
|
if (ctx->Color.AlphaEnabled) {
|
||
|
if (gl_alpha_test( ctx, n, alpha, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
if (ctx->Stencil.Enabled) {
|
||
|
/* first stencil test */
|
||
|
if (gl_stencil_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
/* depth buffering w/ stencil */
|
||
|
gl_depth_stencil_span( ctx, n, x, y, z, mask );
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
else if (ctx->Depth.Test) {
|
||
|
/* regular depth testing */
|
||
|
GLuint m = (*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask );
|
||
|
if (m==0) {
|
||
|
return;
|
||
|
}
|
||
|
if (m<n) {
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & NO_DRAW_BIT) {
|
||
|
/* write no pixels */
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* logic op or blending */
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_rgba_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
else if (ctx->Color.BlendEnabled) {
|
||
|
gl_blend_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
|
||
|
/* Color component masking */
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_color_span( ctx, n, x, y, red, green, blue, alpha );
|
||
|
}
|
||
|
|
||
|
/* write pixels */
|
||
|
(*ctx->Driver.WriteColorSpan)( ctx, n, x, y, red, green, blue, alpha,
|
||
|
write_all ? NULL : mask );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
gl_write_alpha_span( ctx, n, x, y, alpha, write_all ? NULL : mask );
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT) {
|
||
|
/*** Also render to back buffer ***/
|
||
|
MEMCPY( rtmp, r, n * sizeof(GLubyte) );
|
||
|
MEMCPY( gtmp, g, n * sizeof(GLubyte) );
|
||
|
MEMCPY( btmp, b, n * sizeof(GLubyte) );
|
||
|
MEMCPY( atmp, a, n * sizeof(GLubyte) );
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_BACK );
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_rgba_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
else if (ctx->Color.BlendEnabled) {
|
||
|
gl_blend_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_color_span( ctx, n, x, y, red, green, blue, alpha );
|
||
|
}
|
||
|
(*ctx->Driver.WriteColorSpan)( ctx, n, x, y, red, green, blue, alpha,
|
||
|
write_all ? NULL : mask );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
ctx->Buffer->Alpha = ctx->Buffer->BackAlpha;
|
||
|
gl_write_alpha_span( ctx, n, x, y, alpha, write_all ? NULL : mask );
|
||
|
ctx->Buffer->Alpha = ctx->Buffer->FrontAlpha;
|
||
|
}
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_FRONT );
|
||
|
}
|
||
|
|
||
|
}
|
||
|
|
||
|
|
||
|
|
||
|
/*
|
||
|
* Write a horizontal span of color pixels to the frame buffer.
|
||
|
* The color is initially constant for the whole span.
|
||
|
* Alpha-testing, stenciling, depth-testing, and blending are done as needed.
|
||
|
* Input: n - number of pixels in the span
|
||
|
* x, y - location of leftmost pixel in the span
|
||
|
* z - array of [n] z-values
|
||
|
* r, g, b, a - the color of the pixels
|
||
|
* primitive - either GL_POINT, GL_LINE, GL_POLYGON or GL_BITMAP.
|
||
|
*/
|
||
|
void gl_write_monocolor_span( GLcontext *ctx,
|
||
|
GLuint n, GLint x, GLint y, GLdepth z[],
|
||
|
GLint r, GLint g, GLint b, GLint a,
|
||
|
GLenum primitive )
|
||
|
{
|
||
|
GLuint i;
|
||
|
GLubyte mask[MAX_WIDTH];
|
||
|
GLboolean write_all = GL_TRUE;
|
||
|
GLubyte red[MAX_WIDTH], green[MAX_WIDTH], blue[MAX_WIDTH], alpha[MAX_WIDTH];
|
||
|
|
||
|
/* init mask to 1's (all pixels are to be written) */
|
||
|
MEMSET(mask, 1, n);
|
||
|
|
||
|
if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
|
||
|
if (clip_span( ctx,n,x,y,mask)==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
/* Do the scissor test */
|
||
|
if (ctx->Scissor.Enabled) {
|
||
|
if (gl_scissor_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
/* Polygon Stippling */
|
||
|
if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
|
||
|
stipple_polygon_span( ctx, n, x, y, mask );
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
/* Do the alpha test */
|
||
|
if (ctx->Color.AlphaEnabled) {
|
||
|
GLubyte alpha[MAX_WIDTH];
|
||
|
for (i=0;i<n;i++) {
|
||
|
alpha[i] = a;
|
||
|
}
|
||
|
if (gl_alpha_test( ctx, n, alpha, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
if (ctx->Stencil.Enabled) {
|
||
|
/* first stencil test */
|
||
|
if (gl_stencil_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
/* depth buffering w/ stencil */
|
||
|
gl_depth_stencil_span( ctx, n, x, y, z, mask );
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
else if (ctx->Depth.Test) {
|
||
|
/* regular depth testing */
|
||
|
GLuint m = (*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask );
|
||
|
if (m==0) {
|
||
|
return;
|
||
|
}
|
||
|
if (m<n) {
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & NO_DRAW_BIT) {
|
||
|
/* write no pixels */
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (ctx->Color.BlendEnabled || ctx->Color.SWLogicOpEnabled
|
||
|
|| ctx->Color.SWmasking) {
|
||
|
/* assign same color to each pixel */
|
||
|
for (i=0;i<n;i++) {
|
||
|
if (mask[i]) {
|
||
|
red[i] = r;
|
||
|
green[i] = g;
|
||
|
blue[i] = b;
|
||
|
alpha[i] = a;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_rgba_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
else if (ctx->Color.BlendEnabled) {
|
||
|
gl_blend_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
|
||
|
/* Color component masking */
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_color_span( ctx, n, x, y, red, green, blue, alpha );
|
||
|
}
|
||
|
|
||
|
/* write pixels */
|
||
|
(*ctx->Driver.WriteColorSpan)( ctx, n, x, y, red, green, blue, alpha,
|
||
|
write_all ? NULL : mask );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
gl_write_alpha_span( ctx, n, x, y, alpha, write_all ? NULL : mask );
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT) {
|
||
|
/*** Also draw to back buffer ***/
|
||
|
for (i=0;i<n;i++) {
|
||
|
if (mask[i]) {
|
||
|
red[i] = r;
|
||
|
green[i] = g;
|
||
|
blue[i] = b;
|
||
|
alpha[i] = a;
|
||
|
}
|
||
|
}
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_BACK );
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_rgba_span( ctx, n, x, y, red, green, blue, alpha, mask);
|
||
|
}
|
||
|
else if (ctx->Color.BlendEnabled) {
|
||
|
gl_blend_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_color_span( ctx, n, x, y, red, green, blue, alpha );
|
||
|
}
|
||
|
(*ctx->Driver.WriteColorSpan)( ctx, n, x, y, red, green, blue, alpha,
|
||
|
write_all ? NULL : mask );
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_FRONT );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
ctx->Buffer->Alpha = ctx->Buffer->BackAlpha;
|
||
|
gl_write_alpha_span( ctx, n, x, y, alpha,
|
||
|
write_all ? NULL : mask );
|
||
|
ctx->Buffer->Alpha = ctx->Buffer->FrontAlpha;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
(*ctx->Driver.WriteMonocolorSpan)( ctx, n, x, y, mask );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
gl_write_mono_alpha_span( ctx, n, x, y, a, write_all ? NULL : mask );
|
||
|
}
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT) {
|
||
|
/* Also draw to back buffer */
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_BACK );
|
||
|
(*ctx->Driver.WriteMonocolorSpan)( ctx, n, x, y, mask );
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_FRONT );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
ctx->Buffer->Alpha = ctx->Buffer->BackAlpha;
|
||
|
gl_write_mono_alpha_span( ctx, n, x, y, a,
|
||
|
write_all ? NULL : mask );
|
||
|
ctx->Buffer->Alpha = ctx->Buffer->FrontAlpha;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
|
||
|
/*
|
||
|
* Write a horizontal span of textured pixels to the frame buffer.
|
||
|
* The color of each pixel is different.
|
||
|
* Alpha-testing, stenciling, depth-testing, and blending are done
|
||
|
* as needed.
|
||
|
* Input: n - number of pixels in the span
|
||
|
* x, y - location of leftmost pixel in the span
|
||
|
* z - array of [n] z-values
|
||
|
* s, t - array of (s,t) texture coordinates for each pixel
|
||
|
* lambda - array of texture lambda values
|
||
|
* red, green, blue, alpha - array of [n] color components
|
||
|
* primitive - either GL_POINT, GL_LINE, GL_POLYGON or GL_BITMAP.
|
||
|
*/
|
||
|
void gl_write_texture_span( GLcontext *ctx,
|
||
|
GLuint n, GLint x, GLint y, GLdepth z[],
|
||
|
GLfloat s[], GLfloat t[], GLfloat u[],
|
||
|
GLfloat lambda[],
|
||
|
GLubyte r[], GLubyte g[],
|
||
|
GLubyte b[], GLubyte a[],
|
||
|
GLenum primitive )
|
||
|
{
|
||
|
GLubyte mask[MAX_WIDTH];
|
||
|
GLboolean write_all = GL_TRUE;
|
||
|
GLubyte rtmp[MAX_WIDTH], gtmp[MAX_WIDTH], btmp[MAX_WIDTH], atmp[MAX_WIDTH];
|
||
|
GLubyte *red, *green, *blue, *alpha;
|
||
|
|
||
|
/* init mask to 1's (all pixels are to be written) */
|
||
|
MEMSET(mask, 1, n);
|
||
|
|
||
|
if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
|
||
|
if (clip_span( ctx,n,x,y,mask)==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
|
||
|
if (primitive==GL_BITMAP || (ctx->RasterMask & FRONT_AND_BACK_BIT)) {
|
||
|
/* must make a copy of the colors since they may be modified */
|
||
|
MEMCPY( rtmp, r, n * sizeof(GLubyte) );
|
||
|
MEMCPY( gtmp, g, n * sizeof(GLubyte) );
|
||
|
MEMCPY( btmp, b, n * sizeof(GLubyte) );
|
||
|
MEMCPY( atmp, a, n * sizeof(GLubyte) );
|
||
|
red = rtmp;
|
||
|
green = gtmp;
|
||
|
blue = btmp;
|
||
|
alpha = atmp;
|
||
|
}
|
||
|
else {
|
||
|
red = r;
|
||
|
green = g;
|
||
|
blue = b;
|
||
|
alpha = a;
|
||
|
}
|
||
|
|
||
|
/* Texture */
|
||
|
ASSERT(ctx->Texture.Enabled);
|
||
|
gl_texture_pixels( ctx, n, s, t, u, lambda, red, green, blue, alpha );
|
||
|
|
||
|
/* Per-pixel fog */
|
||
|
if (ctx->Fog.Enabled && (ctx->Hint.Fog==GL_NICEST || primitive==GL_BITMAP
|
||
|
|| ctx->Texture.Enabled)) {
|
||
|
gl_fog_color_pixels( ctx, n, z, red, green, blue, alpha );
|
||
|
}
|
||
|
|
||
|
/* Do the scissor test */
|
||
|
if (ctx->Scissor.Enabled) {
|
||
|
if (gl_scissor_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
/* Polygon Stippling */
|
||
|
if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
|
||
|
stipple_polygon_span( ctx, n, x, y, mask );
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
/* Do the alpha test */
|
||
|
if (ctx->Color.AlphaEnabled) {
|
||
|
if (gl_alpha_test( ctx, n, alpha, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
|
||
|
if (ctx->Stencil.Enabled) {
|
||
|
/* first stencil test */
|
||
|
if (gl_stencil_span( ctx, n, x, y, mask )==0) {
|
||
|
return;
|
||
|
}
|
||
|
/* depth buffering w/ stencil */
|
||
|
gl_depth_stencil_span( ctx, n, x, y, z, mask );
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
else if (ctx->Depth.Test) {
|
||
|
/* regular depth testing */
|
||
|
GLuint m = (*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask );
|
||
|
if (m==0) {
|
||
|
return;
|
||
|
}
|
||
|
if (m<n) {
|
||
|
write_all = GL_FALSE;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & NO_DRAW_BIT) {
|
||
|
/* write no pixels */
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* blending */
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_rgba_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
else if (ctx->Color.BlendEnabled) {
|
||
|
gl_blend_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_color_span( ctx, n, x, y, red, green, blue, alpha );
|
||
|
}
|
||
|
|
||
|
/* write pixels */
|
||
|
(*ctx->Driver.WriteColorSpan)( ctx, n, x, y, red, green, blue, alpha,
|
||
|
write_all ? NULL : mask );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
gl_write_alpha_span( ctx, n, x, y, alpha, write_all ? NULL : mask );
|
||
|
}
|
||
|
|
||
|
if (ctx->RasterMask & FRONT_AND_BACK_BIT) {
|
||
|
/* Also draw to back buffer */
|
||
|
MEMCPY( rtmp, r, n * sizeof(GLubyte) );
|
||
|
MEMCPY( gtmp, g, n * sizeof(GLubyte) );
|
||
|
MEMCPY( btmp, b, n * sizeof(GLubyte) );
|
||
|
MEMCPY( atmp, a, n * sizeof(GLubyte) );
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_BACK );
|
||
|
if (ctx->Color.SWLogicOpEnabled) {
|
||
|
gl_logicop_rgba_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
else if (ctx->Color.BlendEnabled) {
|
||
|
gl_blend_span( ctx, n, x, y, red, green, blue, alpha, mask );
|
||
|
}
|
||
|
if (ctx->Color.SWmasking) {
|
||
|
gl_mask_color_span( ctx, n, x, y, red, green, blue, alpha );
|
||
|
}
|
||
|
(*ctx->Driver.WriteColorSpan)( ctx, n, x, y, red, green, blue, alpha,
|
||
|
write_all ? NULL : mask );
|
||
|
(*ctx->Driver.SetBuffer)( ctx, GL_FRONT );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
ctx->Buffer->Alpha = ctx->Buffer->BackAlpha;
|
||
|
gl_write_alpha_span( ctx, n, x, y, alpha, write_all ? NULL : mask );
|
||
|
ctx->Buffer->Alpha = ctx->Buffer->FrontAlpha;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
|
||
|
/*
|
||
|
* Read RGBA pixels from frame buffer. Clipping will be done to prevent
|
||
|
* reading ouside the buffer's boundaries.
|
||
|
*/
|
||
|
void gl_read_color_span( GLcontext *ctx,
|
||
|
GLuint n, GLint x, GLint y,
|
||
|
GLubyte red[], GLubyte green[],
|
||
|
GLubyte blue[], GLubyte alpha[] )
|
||
|
{
|
||
|
register GLuint i;
|
||
|
|
||
|
if (y<0 || y>=ctx->Buffer->Height || x>=ctx->Buffer->Width) {
|
||
|
/* completely above, below, or right */
|
||
|
for (i=0;i<n;i++) {
|
||
|
red[i] = green[i] = blue[i] = alpha[i] = 0;
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
if (x>=0 && x+n<=ctx->Buffer->Width) {
|
||
|
/* OK */
|
||
|
(*ctx->Driver.ReadColorSpan)( ctx, n, x, y, red, green, blue, alpha );
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
gl_read_alpha_span( ctx, n, x, y, alpha );
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
i = 0;
|
||
|
if (x<0) {
|
||
|
while (x<0 && n>0) {
|
||
|
red[i] = green[i] = blue[i] = alpha[i] = 0;
|
||
|
x++;
|
||
|
n--;
|
||
|
i++;
|
||
|
}
|
||
|
}
|
||
|
n = MIN2( n, ctx->Buffer->Width - x );
|
||
|
(*ctx->Driver.ReadColorSpan)( ctx, n, x, y, red+i, green+i, blue+i, alpha+i);
|
||
|
if (ctx->RasterMask & ALPHABUF_BIT) {
|
||
|
gl_read_alpha_span( ctx, n, x, y, alpha+i );
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
|
||
|
|
||
|
/*
|
||
|
* Read CI pixels from frame buffer. Clipping will be done to prevent
|
||
|
* reading ouside the buffer's boundaries.
|
||
|
*/
|
||
|
void gl_read_index_span( GLcontext *ctx,
|
||
|
GLuint n, GLint x, GLint y, GLuint indx[] )
|
||
|
{
|
||
|
register GLuint i;
|
||
|
|
||
|
if (y<0 || y>=ctx->Buffer->Height || x>=ctx->Buffer->Width) {
|
||
|
/* completely above, below, or right */
|
||
|
for (i=0;i<n;i++) {
|
||
|
indx[i] = 0;
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
if (x>=0 && x+n<=ctx->Buffer->Width) {
|
||
|
/* OK */
|
||
|
(*ctx->Driver.ReadIndexSpan)( ctx, n, x, y, indx );
|
||
|
}
|
||
|
else {
|
||
|
i = 0;
|
||
|
if (x<0) {
|
||
|
while (x<0 && n>0) {
|
||
|
indx[i] = 0;
|
||
|
x++;
|
||
|
n--;
|
||
|
i++;
|
||
|
}
|
||
|
}
|
||
|
n = MIN2( n, ctx->Buffer->Width - x );
|
||
|
(*ctx->Driver.ReadIndexSpan)( ctx, n, x, y, indx+i );
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|