www.pudn.com > LightTrack.rar > GraphicsPoly.cpp
/** 3DGPL *************************************************\
* () *
* 2D graphics and 2D clipping extentions for shaded *
* and textured polygons (has to be linked with regular *
* routines). *
* *
* Ifdefs: *
* _CI_ Colour/Intensity model; *
* _RGB_ RGB model; *
* _Z_BUFFER_ Depth array; *
* _PAINTER_ Back front order. *
* *
* Defines: *
* G_flat_polygon Regular polygon; *
* G_shaded_polygon Shaded polygon; *
* G_lin_textured_polygon Textured polygon (approx); *
* G_prp_textured_polygon Textured polygon (true). *
* *
* Internals: *
* GI_scan Scanning an edge; *
* GI_boarder_array_init Init left/right boundaries. *
* *
* (c) 1995-98 Sergei Savchenko, (savs@cs.mcgill.ca) *
\**********************************************************/
//GraphicsPoly.cpp
#include "LightTrack.h" /* hardware specific stuff */
#include "Colour.h" /* colour and light */
#include "Clipper.h" /* 2D clipping */
#include "Graphics.h" /* 2D macros */
#include "Engine.h" /* M_LNG_SHADED */
#include /* INT_MAX and INT_MIN */
extern HW_pixel *G_c_buffer; /* the bitmap's bits */
extern int G_page_start; /* always 0 for _MONO_ */
#if defined(_Z_BUFFER_)
extern int *G_z_buffer; /* Z buffer */
#endif
#define G_LINEAR 32 /* interpolate for */
int G_miny,G_maxy; /* vertical boundaries */
int G_x_start[HW_SCREEN_Y_SIZE]; /* polygon's */
int G_x_end[HW_SCREEN_Y_SIZE]; /* horizontal boundaries */
HW_32_bit G_0_start[HW_SCREEN_Y_SIZE]; /* [32-G_P].[G_P] values */
HW_32_bit G_0_end[HW_SCREEN_Y_SIZE]; /* the thingie is to work faster */
HW_32_bit G_1_start[HW_SCREEN_Y_SIZE]; /* then multidimensional array */
HW_32_bit G_1_end[HW_SCREEN_Y_SIZE]; /* hope so, */
HW_32_bit G_2_start[HW_SCREEN_Y_SIZE];
HW_32_bit G_2_end[HW_SCREEN_Y_SIZE]; /* space for interpolating */
HW_32_bit G_3_start[HW_SCREEN_Y_SIZE]; /* Z R G B Tx Ty */
HW_32_bit G_3_end[HW_SCREEN_Y_SIZE];
HW_32_bit G_4_start[HW_SCREEN_Y_SIZE];
HW_32_bit G_4_end[HW_SCREEN_Y_SIZE];
HW_32_bit G_5_start[HW_SCREEN_Y_SIZE];
HW_32_bit G_5_end[HW_SCREEN_Y_SIZE];
HW_32_bit *G_start[C_MAX_DIMENSIONS]=
{G_0_start,G_1_start,G_2_start,G_3_start,G_4_start,G_5_start};
HW_32_bit *G_end[C_MAX_DIMENSIONS]=
{G_0_end,G_1_end,G_2_end,G_3_end,G_4_end,G_5_end};
#if defined(_CI_)
#if defined(_Z_BUFFER_) /* Z I Tx Ty */
#define G_Z_INDX_START G_0_start /* indexed colour, z-buffer */
#define G_I_INDX_START G_1_start
#define G_TX_INDX_START G_2_start
#define G_TY_INDX_START G_3_start
#define G_Z_INDX_END G_0_end /* indexed colour, z-buffer */
#define G_I_INDX_END G_1_end
#define G_TX_INDX_END G_2_end
#define G_TY_INDX_END G_3_end
#endif
#if defined(_PAINTER_) /* I Tx Ty */
#define G_I_INDX_START G_0_start /* indexed colour, painter */
#define G_TX_INDX_START G_1_start
#define G_TY_INDX_START G_2_start
#define G_I_INDX_END G_0_end /* indexed colour, painter */
#define G_TX_INDX_END G_1_end
#define G_TY_INDX_END G_2_end
#endif
#endif
#if defined(_RGB_)
#if defined(_Z_BUFFER_) /* Z R G B Tx Ty */
#define G_Z_INDX_START G_0_start /* RGB colour, z-buffer */
#define G_R_INDX_START G_1_start
#define G_G_INDX_START G_2_start
#define G_B_INDX_START G_3_start
#define G_TX_INDX_START G_4_start
#define G_TY_INDX_START G_5_start
#define G_Z_INDX_END G_0_end /* RGB colour, z-buffer */
#define G_R_INDX_END G_1_end
#define G_G_INDX_END G_2_end
#define G_B_INDX_END G_3_end
#define G_TX_INDX_END G_4_end
#define G_TY_INDX_END G_5_end
#endif
#if defined(_PAINTER_) /* R G B Tx Ty */
#define G_R_INDX_START G_0_start /* RGB colou, painter */
#define G_G_INDX_START G_1_start
#define G_B_INDX_START G_2_start
#define G_TX_INDX_START G_3_start
#define G_TY_INDX_START G_4_start
#define G_R_INDX_END G_0_end /* RGB colou, painter */
#define G_G_INDX_END G_1_end
#define G_B_INDX_END G_2_end
#define G_TX_INDX_END G_3_end
#define G_TY_INDX_END G_4_end
#endif
#endif
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
* INTERNAL: Scan converting a N dimensional line. *
* --------- *
* SETS: G_x_start,G_x_end,G_start,G_end,G_miny,G_maxy *
* ----- *
\* * * * * * * * * * * * * * * * * * * * * * * * * * * * */
void GI_scan(int *edges,int dimension,int skip)
{
HW_32_bit cur_v[C_MAX_DIMENSIONS]; /* initial values for Z+ dims */
HW_32_bit inc_v[C_MAX_DIMENSIONS]; /* increment for Z+ dimensions */
int dx,dy,long_d,short_d;
register int d,add_dh,add_dl;
register int inc_xh,inc_yh,inc_xl,inc_yl;
int x,y,i,j;
int *v1,*v2; /* first and second vertices */
v1=edges; edges+=skip; v2=edges; /* length ints in each */
if(C_line_y_clipping(&v1,&v2,dimension)) /* vertical clipping */
{
dx=*v2++; dy=*v2++; /* extracting 2-D coordinates */
x=*v1++; y=*v1++; /* v2/v1 point remaining dim-2 */
dimension-=2;
if(yG_maxy) G_maxy=y;
if(dyG_maxy) G_maxy=dy; /* updating vertical size */
dx-=x; dy-=y; /* ranges */
if(dx<0){dx=-dx; inc_xh=-1; inc_xl=-1;} /* making sure dx and dy >0 */
else { inc_xh=1; inc_xl=1; } /* adjusting increments */
if(dy<0){dy=-dy; inc_yh=-1; inc_yl=-1;}
else { inc_yh=1; inc_yl=1; }
if(dx>dy){long_d=dx;short_d=dy;inc_yl=0;} /* long range,&make sure either */
else {long_d=dy;short_d=dx;inc_xl=0;} /* x or y is changed in L case */
d=2*short_d-long_d; /* initial value of d */
add_dl=2*short_d; /* d adjustment for H case */
add_dh=2*(short_d-long_d); /* d adjustment for L case */
#if defined(_Z_BUFFER_)
cur_v[0]=((HW_32_bit)v1[0])<0)
inc_v[0]=(((HW_32_bit)(v2[0]-v1[0]))<0)
inc_v[i]=((HW_32_bit)(v2[i]-v1[i]))/long_d;
}
for(i=0;i<=long_d;i++) /* for all points in long range */
{
if(x=0){x+=inc_xh;y+=inc_yh;d+=add_dh;} /* previous point was H type */
else {x+=inc_xl;y+=inc_yl;d+=add_dl;} /* previous point was L type */
for(j=0;j(cur_z>>G_P)) /* Z buffer check */
{
*adr_z=cur_z>>G_P; /* store new deapth here */
*adr_c=hwcolour; /* flat colour here */
}
cur_z+=inc_z; /* next value for Z */
}
#endif
#if defined(_PAINTER_)
HW_set_pixel(adr_c,span+1,hwcolour); /* drawing a strip */
#endif
}
}
}
/**********************************************************\
* Rendering an Interpolatively shaded polygon. *
* Accepts a stream of three-tuples ( X Y Intensity ) *
* for _CI_ and 5-tuples ( X Y R G B ) for _RGB_ *
* similarely it is ( X Y Z etc. ) if _Z_BUFFER_ *
\**********************************************************/
void G_shaded_polygon(int *edges,int length,HW_pixel colour)
{
int new_edges[G_MAX_POLYGON_VERTICES*G_LNG_SHADED];
int new_length,i;
long pos;
register HW_pixel *adr_c;
register int beg,end,span;
#if defined(_CI_)
register HW_32_bit cur_i,inc_i; /* current colour */
#endif
#if defined(_RGB_)
register HW_32_bit cur_r,inc_r,cur_g,inc_g,cur_b,inc_b;
#endif
#if defined(_Z_BUFFER_)
int *adr_z; /* position in the Z buffer */
register HW_32_bit cur_z,inc_z; /* current depth */
#endif
GI_boarder_array_init(); /* initializing the array */
new_length=C_polygon_x_clipping(edges,new_edges,G_LNG_SHADED,length);
for(i=0;i(cur_z>>G_P)) /* Z buffer check */
{
*adr_z=cur_z>>G_P; /* store new deapth here */
#endif
#if defined(_PAINTER_)
for(;beg<=end;beg++,adr_c++) /* same, no Z check */
{
{
#endif
#if defined(_CI_)
*adr_c=CL_light(colour,cur_i>>G_P); /* rendering single point */
}
cur_i+=inc_i; /* incrementing colour */
#endif
#if defined(_RGB_)
*adr_c=CL_light(colour,cur_r>>G_P,cur_g>>G_P,cur_b>>G_P);
}
cur_r+=inc_r;
cur_g+=inc_g;
cur_b+=inc_b; /* increment RGB */
#endif
#if defined(_Z_BUFFER_)
cur_z+=inc_z; /* increment Z */
#endif
}
}
}
}
/**********************************************************\
* Rendering a leanerely textured polygon. *
* The applied texture is a square colourmap with: *
* *
* log_texture_size=log texture_size *
* 2 *
* *
* Accepts a stream of 5-tuples ( X Y Intensity Tx Ty) *
* for _CI_ and 5-tuples ( X Y R G B Tx Ty) for _RGB_ *
* similarely it is one more ( X Y Z etc. ) if _Z_BUFFER_ *
\**********************************************************/
void G_lin_textured_polygon(int *edges,int length,
HW_pixel *texture,
int log_texture_size
)
{
int new_edges[G_MAX_POLYGON_VERTICES*G_LNG_TEXTURED];
int new_length,i; /* although no edges there yet */
long pos;
register HW_pixel *adr_c;
register int beg,end,span;
register HW_32_bit cur_tx,inc_tx; /* current position inside */
register HW_32_bit cur_ty,inc_ty; /* the texture */
#if defined(_CI_)
register HW_32_bit cur_i,inc_i; /* current colour and it's inc */
#endif
#if defined(_RGB_)
register HW_32_bit cur_r,inc_r,cur_g,inc_g,cur_b,inc_b;
#endif
#if defined(_Z_BUFFER_)
int *adr_z; /* position in the Z buffer */
register HW_32_bit cur_z,inc_z; /* current deapth */
#endif
HW_32_bit txtrmasc=(0x1<<(log_texture_size+G_P))-0x1;
GI_boarder_array_init(); /* initializing the array */
new_length=C_polygon_x_clipping(edges,new_edges,G_LNG_TEXTURED,length);
for(i=0;i(cur_z>>G_P)) /* Z buffer check */
{
*adr_z=cur_z>>G_P;
#endif
#if defined(_PAINTER_)
for(;beg<=end;beg++,adr_c++) /* render all lines: */
{
cur_tx&=txtrmasc;
cur_ty&=txtrmasc; /* wrap around */
{
#endif
#if defined(_CI_)
*adr_c=CL_light(*(texture+((cur_ty>>G_P)<>G_P)),
cur_i>>G_P
);
cur_i+=inc_i;
}
#endif
#if defined(_RGB_)
*adr_c=CL_light(*(texture+((cur_ty>>G_P)<>G_P)),
cur_r>>G_P,cur_g>>G_P,cur_b>>G_P
);
cur_r+=inc_r;
cur_g+=inc_g;
cur_b+=inc_b;
}
#endif
cur_tx+=inc_tx;
cur_ty+=inc_ty; /* new position inside texture */
#if defined(_Z_BUFFER_)
cur_z+=inc_z;
#endif
}
}
}
}
/**********************************************************\
* Rendering a perspectively textured polygon. *
* The applied texture is a square colourmap with: *
* *
* log_texture_size=log texture_size *
* 2 *
* *
* Accepts a stream of 5-tuples ( X Y Intensity Tx Ty) *
* for _CI_ and 5-tuples ( X Y R G B Tx Ty) for _RGB_ *
* similarely it is one more ( X Y Z etc. ) if _Z_BUFFER_ *
* *
* log_texture_scale allowing scaling the texture, i.e. *
* mapping a larger texture onto a smaller polygon or *
* smaller texture onto a larger polygon. *
\**********************************************************/
void G_prp_textured_polygon(int *edges,int length,
int *O,int *u,int *v,
HW_pixel *texture,
int log_texture_size,
int log_texture_scale
)
{
int new_edges[G_MAX_POLYGON_VERTICES*G_LNG_TEXTURED];
int new_length,i;
HW_32_bit Vx,Vy,Vz;
HW_32_bit Ux,Uy,Uz; /* extracting vectors */
HW_32_bit x0,y0,z0;
HW_32_bit ui,uj,uc;
HW_32_bit vi,vj,vc;
HW_32_bit zi,zj,zc; /* back to texture coeficients */
HW_32_bit v0,u0;
HW_32_bit xx,yy,zz,zzz;
long pos;
HW_pixel *adr_c;
register int beg,end,span;
HW_32_bit cur_tx,inc_tx,end_tx,cur_ty,inc_ty,end_ty;
#if defined(_CI_)
register HW_32_bit cur_i,inc_i; /* current colour and it's inc */
#endif
#if defined(_RGB_)
register HW_32_bit cur_r,inc_r,cur_g,inc_g,cur_b,inc_b;
#endif
#if defined(_Z_BUFFER_)
int *adr_z; /* position in the Z buffer */
register HW_32_bit cur_z,inc_z; /* current deapth */
#endif
register int x,y;
HW_32_bit txtrmasc=(0x1<<(log_texture_size+G_P))-0x1;
GI_boarder_array_init(); /* initializing the array */
new_length=C_polygon_x_clipping(edges,new_edges,G_LNG_TEXTURED,length);
for(i=0;i texture point */
Vx=v[0]; Vy=v[1]; Vz=v[2];
Ux=u[0]; Uy=u[1]; Uz=u[2]; /* extracting vectors */
ui=(Vz*y0)-(Vy*z0);
uj=(Vx*z0)-(Vz*x0);
uc=(Vy*x0)-(Vx*y0);
vi=(Uy*z0)-(Uz*y0);
vj=(Uz*x0)-(Ux*z0);
vc=(Ux*y0)-(Uy*x0);
zi=(Vy*Uz)-(Vz*Uy);
zj=(Vz*Ux)-(Vx*Uz);
zc=(Vx*Uy)-(Vy*Ux); /* back to texture coefs */
pos=G_miny*HW_SCREEN_LINE_SIZE+G_page_start;
for(;G_miny>M_camera_log_focus)+uc;
yy=((y*vj)>>M_camera_log_focus)+vc;
zz=((y*zj)>>M_camera_log_focus)+zc; /* valid for the whole run */
if((zzz=zz+((x*zi)>>M_camera_log_focus))!=0)
{
end_tx=((((xx+((x*ui)>>M_camera_log_focus))<>M_camera_log_focus))<end) x=end; /* size of linear run */
cur_tx=end_tx;
cur_ty=end_ty;
if((zzz=zz+((x*zi)>>M_camera_log_focus))!=0)
{
end_tx=((((xx+((x*ui)>>M_camera_log_focus))<>M_camera_log_focus))<(cur_z>>G_P)) /* Z buffer check */
{
*adr_z=cur_z>>G_P;
#endif
#if defined(_PAINTER_)
for(;beg<=x;beg++,adr_c++) /* linear run */
{
cur_tx&=txtrmasc;
cur_ty&=txtrmasc; /* wrap around */
{
#endif
#if defined(_CI_)
*adr_c=CL_light(*(texture+((cur_ty>>G_P)<>G_P)),
cur_i>>G_P
);
cur_i+=inc_i;
}
#endif
#if defined(_RGB_)
*adr_c=CL_light(*(texture+((cur_ty>>G_P)<>G_P)),
cur_r>>G_P,cur_g>>G_P,cur_b>>G_P
);
cur_r+=inc_r;
cur_g+=inc_g;
cur_b+=inc_b;
}
#endif
cur_tx+=inc_tx;
cur_ty+=inc_ty; /* new position in the texture */
#if defined(_Z_BUFFER_)
cur_z+=inc_z;
#endif
}
}
}
}
}
/**********************************************************/