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qzdoom/src/r_drawt.cpp

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/*
** r_drawt.cpp
** Faster column drawers for modern processors
**
**---------------------------------------------------------------------------
** Copyright 1998-2006 Randy Heit
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
** These functions stretch columns into a temporary buffer and then
** map them to the screen. On modern machines, this is faster than drawing
** them directly to the screen.
**
** Will I be able to even understand any of this if I come back to it later?
** Let's hope so. :-)
*/
#include "templates.h"
#include "doomtype.h"
#include "doomdef.h"
#include "r_defs.h"
#include "r_draw.h"
#include "r_main.h"
#include "r_things.h"
#include "v_video.h"
// I should have commented this stuff better.
//
// dc_temp is the buffer R_DrawColumnHoriz writes into.
// dc_tspans points into it.
// dc_ctspan points into dc_tspans.
// horizspan also points into dc_tspans.
// dc_ctspan is advanced while drawing into dc_temp.
// horizspan is advanced up to dc_ctspan when drawing from dc_temp to the screen.
BYTE dc_tempbuff[MAXHEIGHT*4];
BYTE *dc_temp;
unsigned int dc_tspans[4][MAXHEIGHT];
unsigned int *dc_ctspan[4];
unsigned int *horizspan[4];
#ifdef X86_ASM
extern "C" void R_SetupShadedCol();
extern "C" void R_SetupAddCol();
extern "C" void R_SetupAddClampCol();
#endif
#ifndef X86_ASM
// Copies one span at hx to the screen at sx.
void rt_copy1col_c (int hx, int sx, int yl, int yh)
{
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4 + hx];
pitch = dc_pitch;
if (count & 1) {
*dest = *source;
source += 4;
dest += pitch;
}
if (count & 2) {
dest[0] = source[0];
dest[pitch] = source[4];
source += 8;
dest += pitch*2;
}
if (!(count >>= 2))
return;
do {
dest[0] = source[0];
dest[pitch] = source[4];
dest[pitch*2] = source[8];
dest[pitch*3] = source[12];
source += 16;
dest += pitch*4;
} while (--count);
}
// Copies all four spans to the screen starting at sx.
void STACK_ARGS rt_copy4cols_c (int sx, int yl, int yh)
{
int *source;
int *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
dest = (int *)(ylookup[yl] + sx + dc_destorg);
source = (int *)(&dc_temp[yl*4]);
pitch = dc_pitch/sizeof(int);
if (count & 1) {
*dest = *source;
source += 4/sizeof(int);
dest += pitch;
}
if (!(count >>= 1))
return;
do {
dest[0] = source[0];
dest[pitch] = source[4/sizeof(int)];
source += 8/sizeof(int);
dest += pitch*2;
} while (--count);
}
// Maps one span at hx to the screen at sx.
void rt_map1col_c (int hx, int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
colormap = dc_colormap;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4 + hx];
pitch = dc_pitch;
if (count & 1) {
*dest = colormap[*source];
source += 4;
dest += pitch;
}
if (!(count >>= 1))
return;
do {
dest[0] = colormap[source[0]];
dest[pitch] = colormap[source[4]];
source += 8;
dest += pitch*2;
} while (--count);
}
// Maps all four spans to the screen starting at sx.
void STACK_ARGS rt_map4cols_c (int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
colormap = dc_colormap;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4];
pitch = dc_pitch;
if (count & 1) {
dest[0] = colormap[source[0]];
dest[1] = colormap[source[1]];
dest[2] = colormap[source[2]];
dest[3] = colormap[source[3]];
source += 4;
dest += pitch;
}
if (!(count >>= 1))
return;
do {
dest[0] = colormap[source[0]];
dest[1] = colormap[source[1]];
dest[2] = colormap[source[2]];
dest[3] = colormap[source[3]];
dest[pitch] = colormap[source[4]];
dest[pitch+1] = colormap[source[5]];
dest[pitch+2] = colormap[source[6]];
dest[pitch+3] = colormap[source[7]];
source += 8;
dest += pitch*2;
} while (--count);
}
#endif
void rt_Translate1col(const BYTE *translation, int hx, int yl, int yh)
{
int count = yh - yl + 1;
BYTE *source = &dc_temp[yl*4 + hx];
// Things we do to hit the compiler's optimizer with a clue bat:
// 1. Parallelism is explicitly spelled out by using a separate
// C instruction for each assembly instruction. GCC lets me
// have four temporaries, but VC++ spills to the stack with
// more than two. Two is probably optimal, anyway.
// 2. The results of the translation lookups are explicitly
// stored in byte-sized variables. This causes the VC++ code
// to use byte mov instructions in most cases; for apparently
// random reasons, it will use movzx for some places. GCC
// ignores this and uses movzx always.
// Do 8 rows at a time.
for (int count8 = count >> 3; count8; --count8)
{
int c0, c1;
BYTE b0, b1;
c0 = source[0]; c1 = source[4];
b0 = translation[c0]; b1 = translation[c1];
source[0] = b0; source[4] = b1;
c0 = source[8]; c1 = source[12];
b0 = translation[c0]; b1 = translation[c1];
source[8] = b0; source[12] = b1;
c0 = source[16]; c1 = source[20];
b0 = translation[c0]; b1 = translation[c1];
source[16] = b0; source[20] = b1;
c0 = source[24]; c1 = source[28];
b0 = translation[c0]; b1 = translation[c1];
source[24] = b0; source[28] = b1;
source += 32;
}
// Finish by doing 1 row at a time.
for (count &= 7; count; --count, source += 4)
{
source[0] = translation[source[0]];
}
}
void rt_Translate4cols(const BYTE *translation, int yl, int yh)
{
int count = yh - yl + 1;
BYTE *source = &dc_temp[yl*4];
int c0, c1;
BYTE b0, b1;
// Do 2 rows at a time.
for (int count8 = count >> 1; count8; --count8)
{
c0 = source[0]; c1 = source[1];
b0 = translation[c0]; b1 = translation[c1];
source[0] = b0; source[1] = b1;
c0 = source[2]; c1 = source[3];
b0 = translation[c0]; b1 = translation[c1];
source[2] = b0; source[3] = b1;
c0 = source[4]; c1 = source[5];
b0 = translation[c0]; b1 = translation[c1];
source[4] = b0; source[5] = b1;
c0 = source[6]; c1 = source[7];
b0 = translation[c0]; b1 = translation[c1];
source[6] = b0; source[7] = b1;
source += 8;
}
// Do the final row if count was odd.
if (count & 1)
{
c0 = source[0]; c1 = source[1];
b0 = translation[c0]; b1 = translation[c1];
source[0] = b0; source[1] = b1;
c0 = source[2]; c1 = source[3];
b0 = translation[c0]; b1 = translation[c1];
source[2] = b0; source[3] = b1;
}
}
// Translates one span at hx to the screen at sx.
void rt_tlate1col (int hx, int sx, int yl, int yh)
{
rt_Translate1col(dc_translation, hx, yl, yh);
rt_map1col(hx, sx, yl, yh);
}
// Translates all four spans to the screen starting at sx.
void STACK_ARGS rt_tlate4cols (int sx, int yl, int yh)
{
rt_Translate4cols(dc_translation, yl, yh);
rt_map4cols(sx, yl, yh);
}
// Adds one span at hx to the screen at sx without clamping.
void rt_add1col (int hx, int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
DWORD *fg2rgb = dc_srcblend;
DWORD *bg2rgb = dc_destblend;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4 + hx];
pitch = dc_pitch;
colormap = dc_colormap;
do {
DWORD fg = colormap[*source];
DWORD bg = *dest;
fg = fg2rgb[fg];
bg = bg2rgb[bg];
fg = (fg+bg) | 0x1f07c1f;
*dest = RGB32k[0][0][fg & (fg>>15)];
source += 4;
dest += pitch;
} while (--count);
}
// Adds all four spans to the screen starting at sx without clamping.
void STACK_ARGS rt_add4cols_c (int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
DWORD *fg2rgb = dc_srcblend;
DWORD *bg2rgb = dc_destblend;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4];
pitch = dc_pitch;
colormap = dc_colormap;
do {
DWORD fg = colormap[source[0]];
DWORD bg = dest[0];
fg = fg2rgb[fg];
bg = bg2rgb[bg];
fg = (fg+bg) | 0x1f07c1f;
dest[0] = RGB32k[0][0][fg & (fg>>15)];
fg = colormap[source[1]];
bg = dest[1];
fg = fg2rgb[fg];
bg = bg2rgb[bg];
fg = (fg+bg) | 0x1f07c1f;
dest[1] = RGB32k[0][0][fg & (fg>>15)];
fg = colormap[source[2]];
bg = dest[2];
fg = fg2rgb[fg];
bg = bg2rgb[bg];
fg = (fg+bg) | 0x1f07c1f;
dest[2] = RGB32k[0][0][fg & (fg>>15)];
fg = colormap[source[3]];
bg = dest[3];
fg = fg2rgb[fg];
bg = bg2rgb[bg];
fg = (fg+bg) | 0x1f07c1f;
dest[3] = RGB32k[0][0][fg & (fg>>15)];
source += 4;
dest += pitch;
} while (--count);
}
// Translates and adds one span at hx to the screen at sx without clamping.
void rt_tlateadd1col (int hx, int sx, int yl, int yh)
{
rt_Translate1col(dc_translation, hx, yl, yh);
rt_add1col(hx, sx, yl, yh);
}
// Translates and adds all four spans to the screen starting at sx without clamping.
void STACK_ARGS rt_tlateadd4cols (int sx, int yl, int yh)
{
rt_Translate4cols(dc_translation, yl, yh);
rt_add4cols(sx, yl, yh);
}
// Shades one span at hx to the screen at sx.
void rt_shaded1col (int hx, int sx, int yl, int yh)
{
DWORD *fgstart;
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
fgstart = &Col2RGB8[0][dc_color];
colormap = dc_colormap;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4 + hx];
pitch = dc_pitch;
do {
DWORD val = colormap[*source];
DWORD fg = fgstart[val<<8];
val = (Col2RGB8[64-val][*dest] + fg) | 0x1f07c1f;
*dest = RGB32k[0][0][val & (val>>15)];
source += 4;
dest += pitch;
} while (--count);
}
// Shades all four spans to the screen starting at sx.
void STACK_ARGS rt_shaded4cols_c (int sx, int yl, int yh)
{
DWORD *fgstart;
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
fgstart = &Col2RGB8[0][dc_color];
colormap = dc_colormap;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4];
pitch = dc_pitch;
do {
DWORD val;
val = colormap[source[0]];
val = (Col2RGB8[64-val][dest[0]] + fgstart[val<<8]) | 0x1f07c1f;
dest[0] = RGB32k[0][0][val & (val>>15)];
val = colormap[source[1]];
val = (Col2RGB8[64-val][dest[1]] + fgstart[val<<8]) | 0x1f07c1f;
dest[1] = RGB32k[0][0][val & (val>>15)];
val = colormap[source[2]];
val = (Col2RGB8[64-val][dest[2]] + fgstart[val<<8]) | 0x1f07c1f;
dest[2] = RGB32k[0][0][val & (val>>15)];
val = colormap[source[3]];
val = (Col2RGB8[64-val][dest[3]] + fgstart[val<<8]) | 0x1f07c1f;
dest[3] = RGB32k[0][0][val & (val>>15)];
source += 4;
dest += pitch;
} while (--count);
}
// Adds one span at hx to the screen at sx with clamping.
void rt_addclamp1col (int hx, int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
DWORD *fg2rgb = dc_srcblend;
DWORD *bg2rgb = dc_destblend;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4 + hx];
pitch = dc_pitch;
colormap = dc_colormap;
do {
DWORD a = fg2rgb[colormap[*source]] + bg2rgb[*dest];
DWORD b = a;
a |= 0x01f07c1f;
b &= 0x40100400;
a &= 0x3fffffff;
b = b - (b >> 5);
a |= b;
*dest = RGB32k[0][0][(a>>15) & a];
source += 4;
dest += pitch;
} while (--count);
}
// Adds all four spans to the screen starting at sx with clamping.
void STACK_ARGS rt_addclamp4cols_c (int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
DWORD *fg2rgb = dc_srcblend;
DWORD *bg2rgb = dc_destblend;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4];
pitch = dc_pitch;
colormap = dc_colormap;
do {
DWORD a = fg2rgb[colormap[source[0]]] + bg2rgb[dest[0]];
DWORD b = a;
a |= 0x01f07c1f;
b &= 0x40100400;
a &= 0x3fffffff;
b = b - (b >> 5);
a |= b;
dest[0] = RGB32k[0][0][(a>>15) & a];
a = fg2rgb[colormap[source[1]]] + bg2rgb[dest[1]];
b = a;
a |= 0x01f07c1f;
b &= 0x40100400;
a &= 0x3fffffff;
b = b - (b >> 5);
a |= b;
dest[1] = RGB32k[0][0][(a>>15) & a];
a = fg2rgb[colormap[source[2]]] + bg2rgb[dest[2]];
b = a;
a |= 0x01f07c1f;
b &= 0x40100400;
a &= 0x3fffffff;
b = b - (b >> 5);
a |= b;
dest[2] = RGB32k[0][0][(a>>15) & a];
a = fg2rgb[colormap[source[3]]] + bg2rgb[dest[3]];
b = a;
a |= 0x01f07c1f;
b &= 0x40100400;
a &= 0x3fffffff;
b = b - (b >> 5);
a |= b;
dest[3] = RGB32k[0][0][(a>>15) & a];
source += 4;
dest += pitch;
} while (--count);
}
// Translates and adds one span at hx to the screen at sx with clamping.
void rt_tlateaddclamp1col (int hx, int sx, int yl, int yh)
{
rt_Translate1col(dc_translation, hx, yl, yh);
rt_addclamp1col(hx, sx, yl, yh);
}
// Translates and adds all four spans to the screen starting at sx with clamping.
void STACK_ARGS rt_tlateaddclamp4cols (int sx, int yl, int yh)
{
rt_Translate4cols(dc_translation, yl, yh);
rt_addclamp4cols(sx, yl, yh);
}
// Subtracts one span at hx to the screen at sx with clamping.
void rt_subclamp1col (int hx, int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
DWORD *fg2rgb = dc_srcblend;
DWORD *bg2rgb = dc_destblend;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4 + hx];
pitch = dc_pitch;
colormap = dc_colormap;
do {
DWORD a = (fg2rgb[colormap[*source]] | 0x40100400) - bg2rgb[*dest];
DWORD b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
*dest = RGB32k[0][0][(a>>15) & a];
source += 4;
dest += pitch;
} while (--count);
}
// Subtracts all four spans to the screen starting at sx with clamping.
void STACK_ARGS rt_subclamp4cols (int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
DWORD *fg2rgb = dc_srcblend;
DWORD *bg2rgb = dc_destblend;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4];
pitch = dc_pitch;
colormap = dc_colormap;
do {
DWORD a = (fg2rgb[colormap[source[0]]] | 0x40100400) - bg2rgb[dest[0]];
DWORD b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
dest[0] = RGB32k[0][0][(a>>15) & a];
a = (fg2rgb[colormap[source[1]]] | 0x40100400) - bg2rgb[dest[1]];
b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
dest[1] = RGB32k[0][0][(a>>15) & a];
a = (fg2rgb[colormap[source[2]]] | 0x40100400) - bg2rgb[dest[2]];
b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
dest[2] = RGB32k[0][0][(a>>15) & a];
a = (fg2rgb[colormap[source[3]]] | 0x40100400) - bg2rgb[dest[3]];
b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
dest[3] = RGB32k[0][0][(a>>15) & a];
source += 4;
dest += pitch;
} while (--count);
}
// Translates and subtracts one span at hx to the screen at sx with clamping.
void rt_tlatesubclamp1col (int hx, int sx, int yl, int yh)
{
rt_Translate1col(dc_translation, hx, yl, yh);
rt_subclamp1col(hx, sx, yl, yh);
}
// Translates and subtracts all four spans to the screen starting at sx with clamping.
void STACK_ARGS rt_tlatesubclamp4cols (int sx, int yl, int yh)
{
rt_Translate4cols(dc_translation, yl, yh);
rt_subclamp4cols(sx, yl, yh);
}
// Subtracts one span at hx from the screen at sx with clamping.
void rt_revsubclamp1col (int hx, int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
DWORD *fg2rgb = dc_srcblend;
DWORD *bg2rgb = dc_destblend;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4 + hx];
pitch = dc_pitch;
colormap = dc_colormap;
do {
DWORD a = (bg2rgb[*dest] | 0x40100400) - fg2rgb[colormap[*source]];
DWORD b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
*dest = RGB32k[0][0][(a>>15) & a];
source += 4;
dest += pitch;
} while (--count);
}
// Subtracts all four spans from the screen starting at sx with clamping.
void STACK_ARGS rt_revsubclamp4cols (int sx, int yl, int yh)
{
BYTE *colormap;
BYTE *source;
BYTE *dest;
int count;
int pitch;
count = yh-yl;
if (count < 0)
return;
count++;
DWORD *fg2rgb = dc_srcblend;
DWORD *bg2rgb = dc_destblend;
dest = ylookup[yl] + sx + dc_destorg;
source = &dc_temp[yl*4];
pitch = dc_pitch;
colormap = dc_colormap;
do {
DWORD a = (bg2rgb[dest[0]] | 0x40100400) - fg2rgb[colormap[source[0]]];
DWORD b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
dest[0] = RGB32k[0][0][(a>>15) & a];
a = (bg2rgb[dest[1]] | 0x40100400) - fg2rgb[colormap[source[1]]];
b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
dest[1] = RGB32k[0][0][(a>>15) & a];
a = (bg2rgb[dest[2]] | 0x40100400) - fg2rgb[colormap[source[2]]];
b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
dest[2] = RGB32k[0][0][(a>>15) & a];
a = (bg2rgb[dest[3]] | 0x40100400) - fg2rgb[colormap[source[3]]];
b = a;
b &= 0x40100400;
b = b - (b >> 5);
a &= b;
a |= 0x01f07c1f;
dest[3] = RGB32k[0][0][(a>>15) & a];
source += 4;
dest += pitch;
} while (--count);
}
// Translates and subtracts one span at hx from the screen at sx with clamping.
void rt_tlaterevsubclamp1col (int hx, int sx, int yl, int yh)
{
rt_Translate1col(dc_translation, hx, yl, yh);
rt_revsubclamp1col(hx, sx, yl, yh);
}
// Translates and subtracts all four spans from the screen starting at sx with clamping.
void STACK_ARGS rt_tlaterevsubclamp4cols (int sx, int yl, int yh)
{
rt_Translate4cols(dc_translation, yl, yh);
rt_revsubclamp4cols(sx, yl, yh);
}
// Copies all spans in all four columns to the screen starting at sx.
// sx should be dword-aligned.
void rt_draw4cols (int sx)
{
int x, bad;
unsigned int maxtop, minbot, minnexttop;
// Place a dummy "span" in each column. These don't get
// drawn. They're just here to avoid special cases in the
// max/min calculations below.
for (x = 0; x < 4; ++x)
{
dc_ctspan[x][0] = screen->GetHeight()+1;
dc_ctspan[x][1] = screen->GetHeight();
}
#ifdef X86_ASM
// Setup assembly routines for changed colormaps or other parameters.
if (hcolfunc_post4 == rt_shaded4cols)
{
R_SetupShadedCol();
}
else if (hcolfunc_post4 == rt_addclamp4cols || hcolfunc_post4 == rt_tlateaddclamp4cols)
{
R_SetupAddClampCol();
}
else if (hcolfunc_post4 == rt_add4cols || hcolfunc_post4 == rt_tlateadd4cols)
{
R_SetupAddCol();
}
#endif
for (;;)
{
// If a column is out of spans, mark it as such
bad = 0;
minnexttop = 0xffffffff;
for (x = 0; x < 4; ++x)
{
if (horizspan[x] >= dc_ctspan[x])
{
bad |= 1 << x;
}
else if ((horizspan[x]+2)[0] < minnexttop)
{
minnexttop = (horizspan[x]+2)[0];
}
}
// Once all columns are out of spans, we're done
if (bad == 15)
{
return;
}
// Find the largest shared area for the spans in each column
maxtop = MAX (MAX (horizspan[0][0], horizspan[1][0]),
MAX (horizspan[2][0], horizspan[3][0]));
minbot = MIN (MIN (horizspan[0][1], horizspan[1][1]),
MIN (horizspan[2][1], horizspan[3][1]));
// If there is no shared area with these spans, draw each span
// individually and advance to the next spans until we reach a shared area.
// However, only draw spans down to the highest span in the next set of
// spans. If we allow the entire height of a span to be drawn, it could
// prevent any more shared areas from being drawn in these four columns.
//
// Example: Suppose we have the following arrangement:
// A CD
// A CD
// B D
// B D
// aB D
// aBcD
// aBcD
// aBc
//
// If we draw the entire height of the spans, we end up drawing this first:
// A CD
// A CD
// B D
// B D
// B D
// B D
// B D
// B D
// B
//
// This leaves only the "a" and "c" columns to be drawn, and they are not
// part of a shared area, but if we can include B and D with them, we can
// get a shared area. So we cut off everything in the first set just
// above the "a" column and end up drawing this first:
// A CD
// A CD
// B D
// B D
//
// Then the next time through, we have the following arrangement with an
// easily shared area to draw:
// aB D
// aBcD
// aBcD
// aBc
if (bad != 0 || maxtop > minbot)
{
int drawcount = 0;
for (x = 0; x < 4; ++x)
{
if (!(bad & 1))
{
if (horizspan[x][1] < minnexttop)
{
hcolfunc_post1 (x, sx+x, horizspan[x][0], horizspan[x][1]);
horizspan[x] += 2;
drawcount++;
}
else if (minnexttop > horizspan[x][0])
{
hcolfunc_post1 (x, sx+x, horizspan[x][0], minnexttop-1);
horizspan[x][0] = minnexttop;
drawcount++;
}
}
bad >>= 1;
}
// Drawcount *should* always be non-zero. The reality is that some situations
// can make this not true. Unfortunately, I'm not sure what those situations are.
if (drawcount == 0)
{
return;
}
continue;
}
// Draw any span fragments above the shared area.
for (x = 0; x < 4; ++x)
{
if (maxtop > horizspan[x][0])
{
hcolfunc_post1 (x, sx+x, horizspan[x][0], maxtop-1);
}
}
// Draw the shared area.
hcolfunc_post4 (sx, maxtop, minbot);
// For each column, if part of the span is past the shared area,
// set its top to just below the shared area. Otherwise, advance
// to the next span in that column.
for (x = 0; x < 4; ++x)
{
if (minbot < horizspan[x][1])
{
horizspan[x][0] = minbot+1;
}
else
{
horizspan[x] += 2;
}
}
}
}
// Before each pass through a rendering loop that uses these routines,
// call this function to set up the span pointers.
void rt_initcols (BYTE *buff)
{
int y;
dc_temp = buff == NULL ? dc_tempbuff : buff;
for (y = 3; y >= 0; y--)
horizspan[y] = dc_ctspan[y] = &dc_tspans[y][0];
}
// Stretches a column into a temporary buffer which is later
// drawn to the screen along with up to three other columns.
void R_DrawColumnHorizP_C (void)
{
int count = dc_count;
BYTE *dest;
fixed_t fracstep;
fixed_t frac;
if (count <= 0)
return;
{
int x = dc_x & 3;
unsigned int **span;
span = &dc_ctspan[x];
(*span)[0] = dc_yl;
(*span)[1] = dc_yh;
*span += 2;
dest = &dc_temp[x + 4*dc_yl];
}
fracstep = dc_iscale;
frac = dc_texturefrac;
{
const BYTE *source = dc_source;
if (count & 1) {
*dest = source[frac>>FRACBITS]; dest += 4; frac += fracstep;
}
if (count & 2) {
dest[0] = source[frac>>FRACBITS]; frac += fracstep;
dest[4] = source[frac>>FRACBITS]; frac += fracstep;
dest += 8;
}
if (count & 4) {
dest[0] = source[frac>>FRACBITS]; frac += fracstep;
dest[4] = source[frac>>FRACBITS]; frac += fracstep;
dest[8] = source[frac>>FRACBITS]; frac += fracstep;
dest[12]= source[frac>>FRACBITS]; frac += fracstep;
dest += 16;
}
count >>= 3;
if (!count) return;
do
{
dest[0] = source[frac>>FRACBITS]; frac += fracstep;
dest[4] = source[frac>>FRACBITS]; frac += fracstep;
dest[8] = source[frac>>FRACBITS]; frac += fracstep;
dest[12]= source[frac>>FRACBITS]; frac += fracstep;
dest[16]= source[frac>>FRACBITS]; frac += fracstep;
dest[20]= source[frac>>FRACBITS]; frac += fracstep;
dest[24]= source[frac>>FRACBITS]; frac += fracstep;
dest[28]= source[frac>>FRACBITS]; frac += fracstep;
dest += 32;
} while (--count);
}
}
// [RH] Just fills a column with a given color
void R_FillColumnHorizP (void)
{
int count = dc_count;
BYTE color = dc_color;
BYTE *dest;
if (count <= 0)
return;
{
int x = dc_x & 3;
unsigned int **span = &dc_ctspan[x];
(*span)[0] = dc_yl;
(*span)[1] = dc_yh;
*span += 2;
dest = &dc_temp[x + 4*dc_yl];
}
if (count & 1) {
*dest = color;
dest += 4;
}
if (!(count >>= 1))
return;
do {
dest[0] = color; dest[4] = color;
dest += 8;
} while (--count);
}
// Same as R_DrawMaskedColumn() except that it always uses R_DrawColumnHoriz().
void R_DrawMaskedColumnHoriz (const BYTE *column, const FTexture::Span *span)
{
while (span->Length != 0)
{
const int length = span->Length;
const int top = span->TopOffset;
// calculate unclipped screen coordinates for post
dc_yl = (sprtopscreen + spryscale * top) >> FRACBITS;
dc_yh = (sprtopscreen + spryscale * (top + length) - FRACUNIT) >> FRACBITS;
if (sprflipvert)
{
swapvalues (dc_yl, dc_yh);
}
if (dc_yh >= mfloorclip[dc_x])
{
dc_yh = mfloorclip[dc_x] - 1;
}
if (dc_yl < mceilingclip[dc_x])
{
dc_yl = mceilingclip[dc_x];
}
if (dc_yl <= dc_yh)
{
if (sprflipvert)
{
dc_texturefrac = (dc_yl*dc_iscale) - (top << FRACBITS)
- FixedMul (centeryfrac, dc_iscale) - dc_texturemid;
const fixed_t maxfrac = length << FRACBITS;
while (dc_texturefrac >= maxfrac)
{
if (++dc_yl > dc_yh)
goto nextpost;
dc_texturefrac += dc_iscale;
}
fixed_t endfrac = dc_texturefrac + (dc_yh-dc_yl)*dc_iscale;
while (endfrac < 0)
{
if (--dc_yh < dc_yl)
goto nextpost;
endfrac -= dc_iscale;
}
}
else
{
dc_texturefrac = dc_texturemid - (top << FRACBITS)
+ (dc_yl*dc_iscale) - FixedMul (centeryfrac-FRACUNIT, dc_iscale);
while (dc_texturefrac < 0)
{
if (++dc_yl > dc_yh)
goto nextpost;
dc_texturefrac += dc_iscale;
}
fixed_t endfrac = dc_texturefrac + (dc_yh-dc_yl)*dc_iscale;
const fixed_t maxfrac = length << FRACBITS;
if (dc_yh < mfloorclip[dc_x]-1 && endfrac < maxfrac - dc_iscale)
{
dc_yh++;
}
else while (endfrac >= maxfrac)
{
if (--dc_yh < dc_yl)
goto nextpost;
endfrac -= dc_iscale;
}
}
dc_source = column + top;
dc_dest = ylookup[dc_yl] + dc_x + dc_destorg;
dc_count = dc_yh - dc_yl + 1;
hcolfunc_pre ();
}
nextpost:
span++;
}
if (sprflipvert)
{
unsigned int *front = horizspan[dc_x&3];
unsigned int *back = dc_ctspan[dc_x&3] - 2;
// Reorder the posts so that they get drawn top-to-bottom
// instead of bottom-to-top.
while (front < back)
{
swapvalues (front[0], back[0]);
swapvalues (front[1], back[1]);
front += 2;
back -= 2;
}
}
}
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