/*
* Portions of this file are copyright Rebirth contributors and licensed as
* described in COPYING.txt.
* Portions of this file are copyright Parallax Software and licensed
* according to the Parallax license below.
* See COPYING.txt for license details.
THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING, AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
*/
/*
*
* Flat shader derived from texture mapper (a little slow)
*
*/
#include "maths.h"
#include "vecmat.h"
#include "gr.h"
#include "grdef.h"
#include "texmap.h"
#include "texmapl.h"
#include "scanline.h"
#include "compiler-range_for.h"
#include "partial_range.h"
//#include "tmapext.h"
#if !DXX_USE_OGL
#include "3d.h"
#include "dxxerror.h"
#include "3d.h"
#include "dxxerror.h"
namespace dcx {
static void gr_upoly_tmap_ylr(grs_canvas &, uint_fast32_t nverts, const int *vert, uint8_t color);
// -------------------------------------------------------------------------------------
// Texture map current scanline.
// Uses globals Du_dx and Dv_dx to incrementally compute u,v coordinates
// -------------------------------------------------------------------------------------
static void tmap_scanline_flat(grs_canvas &canvas, int y, fix xleft, fix xright)
{
if (xright < xleft)
return;
// setup to call assembler scanline renderer
fx_y = y;
fx_xleft = xleft/F1_0; // (xleft >> 16) != xleft/F1_0 for negative numbers, f2i caused random crashes
fx_xright = xright/F1_0;
if (canvas.cv_fade_level >= GR_FADE_OFF)
cur_tmap_scanline_flat();
else {
cur_tmap_scanline_shaded(canvas.cv_fade_level);
}
}
//--unused-- void tmap_scanline_shaded(int y, fix xleft, fix xright)
//--unused-- {
//--unused-- fix dx;
//--unused--
//--unused-- dx = xright - xleft;
//--unused--
//--unused-- // setup to call assembler scanline renderer
//--unused--
//--unused-- fx_y = y << 16;
//--unused-- fx_xleft = xleft;
//--unused-- fx_xright = xright;
//--unused--
//--unused-- asm_tmap_scanline_shaded();
//--unused-- }
// -------------------------------------------------------------------------------------
// Render a texture map.
// Linear in outer loop, linear in inner loop.
// -------------------------------------------------------------------------------------
static void texture_map_flat(grs_canvas &canvas, const g3ds_tmap &t, int color)
{
int vlt,vrt,vlb,vrb; // vertex left top, vertex right top, vertex left bottom, vertex right bottom
int topy,boty,dy;
fix dx_dy_left,dx_dy_right;
int max_y_vertex;
fix xleft,xright;
fix recip_dy;
auto &v3d = t.verts;
tmap_flat_color = color;
// Determine top and bottom y coords.
compute_y_bounds(t,vlt,vlb,vrt,vrb,max_y_vertex);
// Set top and bottom (of entire texture map) y coordinates.
topy = f2i(v3d[vlt].y2d);
boty = f2i(v3d[max_y_vertex].y2d);
// Set amount to change x coordinate for each advance to next scanline.
dy = f2i(t.verts[vlb].y2d) - f2i(t.verts[vlt].y2d);
recip_dy = fix_recip(dy);
dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
dy = f2i(t.verts[vrb].y2d) - f2i(t.verts[vrt].y2d);
recip_dy = fix_recip(dy);
dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
// Set initial values for x, u, v
xleft = v3d[vlt].x2d;
xright = v3d[vrt].x2d;
// scan all rows in texture map from top through first break.
// @mk: Should we render the scanline for y==boty? This violates Matt's spec.
for (int y = topy; y < boty; y++) {
// See if we have reached the end of the current left edge, and if so, set
// new values for dx_dy and x,u,v
if (y == f2i(v3d[vlb].y2d)) {
// Handle problem of double points. Search until y coord is different. Cannot get
// hung in an infinite loop because we know there is a vertex with a lower y coordinate
// because in the for loop, we don't scan all spanlines.
while (y == f2i(v3d[vlb].y2d)) {
vlt = vlb;
vlb = prevmod(vlb,t.nv);
}
dy = f2i(t.verts[vlb].y2d) - f2i(t.verts[vlt].y2d);
recip_dy = fix_recip(dy);
dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
xleft = v3d[vlt].x2d;
}
// See if we have reached the end of the current left edge, and if so, set
// new values for dx_dy and x. Not necessary to set new values for u,v.
if (y == f2i(v3d[vrb].y2d)) {
while (y == f2i(v3d[vrb].y2d)) {
vrt = vrb;
vrb = succmod(vrb,t.nv);
}
dy = f2i(t.verts[vrb].y2d) - f2i(t.verts[vrt].y2d);
recip_dy = fix_recip(dy);
dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
xright = v3d[vrt].x2d;
}
tmap_scanline_flat(canvas, y, xleft, xright);
xleft += dx_dy_left;
xright += dx_dy_right;
}
tmap_scanline_flat(canvas, boty, xleft, xright);
}
// -----------------------------------------------------------------------------------------
// This is the gr_upoly-like interface to the texture mapper which uses texture-mapper compatible
// (ie, avoids cracking) edge/delta computation.
void gr_upoly_tmap(grs_canvas &canvas, uint_fast32_t nverts, const std::array<fix, MAX_POINTS_IN_POLY * 2> &vert, const uint8_t color)
{
gr_upoly_tmap_ylr(canvas, nverts, vert.data(), color);
}
struct pnt2d {
fix x,y;
};
//this takes the same partms as draw_tmap, but draws a flat-shaded polygon
void draw_tmap_flat(grs_canvas &canvas, const grs_bitmap &bp, uint_fast32_t nverts, const g3s_point *const *vertbuf)
{
union {
std::array<pnt2d, MAX_TMAP_VERTS> points;
std::array<int, MAX_TMAP_VERTS * (sizeof(pnt2d) / sizeof(int))> ipoints;
};
static_assert(sizeof(points) == sizeof(ipoints), "array size mismatch");
fix average_light;
Assert(nverts < MAX_TMAP_VERTS);
average_light = vertbuf[0]->p3_l;
for (int i=1; i<nverts; i++)
average_light += vertbuf[i]->p3_l;
if (nverts == 4)
average_light = f2i(average_light * NUM_LIGHTING_LEVELS/4);
else
average_light = f2i(average_light * NUM_LIGHTING_LEVELS/nverts);
if (average_light < 0)
average_light = 0;
else if (average_light > NUM_LIGHTING_LEVELS-1)
average_light = NUM_LIGHTING_LEVELS-1;
color_t color = gr_fade_table[average_light][bp.avg_color];
for (int i=0;i<nverts;i++) {
points[i].x = vertbuf[i]->p3_sx;
points[i].y = vertbuf[i]->p3_sy;
}
gr_upoly_tmap_ylr(canvas, nverts, ipoints.data(), color);
}
// -----------------------------------------------------------------------------------------
//This is like gr_upoly_tmap() but instead of drawing, it calls the specified
//function with ylr values
static void gr_upoly_tmap_ylr(grs_canvas &canvas, uint_fast32_t nverts, const int *vert, const uint8_t color)
{
g3ds_tmap my_tmap;
my_tmap.nv = nverts;
range_for (auto &i, partial_range(my_tmap.verts, nverts))
{
i.x2d = *vert++;
i.y2d = *vert++;
}
texture_map_flat(canvas, my_tmap, color);
}
}
#endif //!OGL