0,0 → 1,450 |
#include "zgl.h" |
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/* fill triangle profile */ |
/* #define PROFILE */ |
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#define CLIP_XMIN (1<<0) |
#define CLIP_XMAX (1<<1) |
#define CLIP_YMIN (1<<2) |
#define CLIP_YMAX (1<<3) |
#define CLIP_ZMIN (1<<4) |
#define CLIP_ZMAX (1<<5) |
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void gl_transform_to_viewport(GLContext *c,GLVertex *v) |
{ |
float winv; |
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/* coordinates */ |
winv=1.0/v->pc.W; |
v->zp.x= (int) ( v->pc.X * winv * c->viewport.scale.X |
+ c->viewport.trans.X ); |
v->zp.y= (int) ( v->pc.Y * winv * c->viewport.scale.Y |
+ c->viewport.trans.Y ); |
v->zp.z= (int) ( v->pc.Z * winv * c->viewport.scale.Z |
+ c->viewport.trans.Z ); |
/* color */ |
if (c->lighting_enabled) { |
v->zp.r=(int)(v->color.v[0] * (ZB_POINT_RED_MAX - ZB_POINT_RED_MIN) |
+ ZB_POINT_RED_MIN); |
v->zp.g=(int)(v->color.v[1] * (ZB_POINT_GREEN_MAX - ZB_POINT_GREEN_MIN) |
+ ZB_POINT_GREEN_MIN); |
v->zp.b=(int)(v->color.v[2] * (ZB_POINT_BLUE_MAX - ZB_POINT_BLUE_MIN) |
+ ZB_POINT_BLUE_MIN); |
} else { |
/* no need to convert to integer if no lighting : take current color */ |
v->zp.r = c->longcurrent_color[0]; |
v->zp.g = c->longcurrent_color[1]; |
v->zp.b = c->longcurrent_color[2]; |
} |
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/* texture */ |
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if (c->texture_2d_enabled) { |
v->zp.s=(int)(v->tex_coord.X * (ZB_POINT_S_MAX - ZB_POINT_S_MIN) |
+ ZB_POINT_S_MIN); |
v->zp.t=(int)(v->tex_coord.Y * (ZB_POINT_T_MAX - ZB_POINT_T_MIN) |
+ ZB_POINT_T_MIN); |
} |
} |
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static void gl_add_select1(GLContext *c,int z1,int z2,int z3) |
{ |
unsigned int min,max; |
min=max=z1; |
if (z2<min) min=z2; |
if (z3<min) min=z3; |
if (z2>max) max=z2; |
if (z3>max) max=z3; |
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gl_add_select(c,0xffffffff-min,0xffffffff-max); |
} |
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/* point */ |
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void gl_draw_point(GLContext *c,GLVertex *p0) |
{ |
if (p0->clip_code == 0) { |
if (c->render_mode == GL_SELECT) { |
gl_add_select(c,p0->zp.z,p0->zp.z); |
} else { |
ZB_plot(c->zb,&p0->zp); |
} |
} |
} |
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/* line */ |
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static inline void interpolate(GLVertex *q,GLVertex *p0,GLVertex *p1,float t) |
{ |
q->pc.X=p0->pc.X+(p1->pc.X-p0->pc.X)*t; |
q->pc.Y=p0->pc.Y+(p1->pc.Y-p0->pc.Y)*t; |
q->pc.Z=p0->pc.Z+(p1->pc.Z-p0->pc.Z)*t; |
q->pc.W=p0->pc.W+(p1->pc.W-p0->pc.W)*t; |
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q->color.v[0]=p0->color.v[0] + (p1->color.v[0]-p0->color.v[0])*t; |
q->color.v[1]=p0->color.v[1] + (p1->color.v[1]-p0->color.v[1])*t; |
q->color.v[2]=p0->color.v[2] + (p1->color.v[2]-p0->color.v[2])*t; |
} |
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/* |
* Line Clipping |
*/ |
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/* Line Clipping algorithm from 'Computer Graphics', Principles and |
Practice */ |
static inline int ClipLine1(float denom,float num,float *tmin,float *tmax) |
{ |
float t; |
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if (denom>0) { |
t=num/denom; |
if (t>*tmax) return 0; |
if (t>*tmin) *tmin=t; |
} else if (denom<0) { |
t=num/denom; |
if (t<*tmin) return 0; |
if (t<*tmax) *tmax=t; |
} else if (num>0) return 0; |
return 1; |
} |
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void gl_draw_line(GLContext *c,GLVertex *p1,GLVertex *p2) |
{ |
float dx,dy,dz,dw,x1,y1,z1,w1; |
float tmin,tmax; |
GLVertex q1,q2; |
int cc1,cc2; |
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cc1=p1->clip_code; |
cc2=p2->clip_code; |
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if ( (cc1 | cc2) == 0) { |
if (c->render_mode == GL_SELECT) { |
gl_add_select1(c,p1->zp.z,p2->zp.z,p2->zp.z); |
} else { |
if (c->depth_test) |
ZB_line_z(c->zb,&p1->zp,&p2->zp); |
else |
ZB_line(c->zb,&p1->zp,&p2->zp); |
} |
} else if ( (cc1&cc2) != 0 ) { |
return; |
} else { |
dx=p2->pc.X-p1->pc.X; |
dy=p2->pc.Y-p1->pc.Y; |
dz=p2->pc.Z-p1->pc.Z; |
dw=p2->pc.W-p1->pc.W; |
x1=p1->pc.X; |
y1=p1->pc.Y; |
z1=p1->pc.Z; |
w1=p1->pc.W; |
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tmin=0; |
tmax=1; |
if (ClipLine1(dx+dw,-x1-w1,&tmin,&tmax) && |
ClipLine1(-dx+dw,x1-w1,&tmin,&tmax) && |
ClipLine1(dy+dw,-y1-w1,&tmin,&tmax) && |
ClipLine1(-dy+dw,y1-w1,&tmin,&tmax) && |
ClipLine1(dz+dw,-z1-w1,&tmin,&tmax) && |
ClipLine1(-dz+dw,z1-w1,&tmin,&tmax)) { |
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interpolate(&q1,p1,p2,tmin); |
interpolate(&q2,p1,p2,tmax); |
gl_transform_to_viewport(c,&q1); |
gl_transform_to_viewport(c,&q2); |
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RGBFtoRGBI(q1.color.v[0],q1.color.v[1],q1.color.v[2],q1.zp.r,q1.zp.g,q1.zp.b); |
RGBFtoRGBI(q2.color.v[0],q2.color.v[1],q2.color.v[2],q2.zp.r,q2.zp.g,q2.zp.b); |
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if (c->depth_test) |
ZB_line_z(c->zb,&q1.zp,&q2.zp); |
else |
ZB_line(c->zb,&q1.zp,&q2.zp); |
} |
} |
} |
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/* triangle */ |
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/* |
* Clipping |
*/ |
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/* We clip the segment [a,b] against the 6 planes of the normal volume. |
* We compute the point 'c' of intersection and the value of the parameter 't' |
* of the intersection if x=a+t(b-a). |
*/ |
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#define clip_func(name,sign,dir,dir1,dir2) \ |
static float name(V4 *c,V4 *a,V4 *b) \ |
{\ |
float t,dX,dY,dZ,dW,den;\ |
dX = (b->X - a->X);\ |
dY = (b->Y - a->Y);\ |
dZ = (b->Z - a->Z);\ |
dW = (b->W - a->W);\ |
den = -(sign d ## dir) + dW;\ |
if (den == 0) t=0;\ |
else t = ( sign a->dir - a->W) / den;\ |
c->dir1 = a->dir1 + t * d ## dir1;\ |
c->dir2 = a->dir2 + t * d ## dir2;\ |
c->W = a->W + t * dW;\ |
c->dir = sign c->W;\ |
return t;\ |
} |
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clip_func(clip_xmin,-,X,Y,Z) |
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clip_func(clip_xmax,+,X,Y,Z) |
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clip_func(clip_ymin,-,Y,X,Z) |
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clip_func(clip_ymax,+,Y,X,Z) |
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clip_func(clip_zmin,-,Z,X,Y) |
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clip_func(clip_zmax,+,Z,X,Y) |
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float (*clip_proc[6])(V4 *,V4 *,V4 *)= { |
clip_xmin,clip_xmax, |
clip_ymin,clip_ymax, |
clip_zmin,clip_zmax |
}; |
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static inline void updateTmp(GLContext *c, |
GLVertex *q,GLVertex *p0,GLVertex *p1,float t) |
{ |
if (c->current_shade_model == GL_SMOOTH) { |
q->color.v[0]=p0->color.v[0] + (p1->color.v[0]-p0->color.v[0])*t; |
q->color.v[1]=p0->color.v[1] + (p1->color.v[1]-p0->color.v[1])*t; |
q->color.v[2]=p0->color.v[2] + (p1->color.v[2]-p0->color.v[2])*t; |
} else { |
q->color.v[0]=p0->color.v[0]; |
q->color.v[1]=p0->color.v[1]; |
q->color.v[2]=p0->color.v[2]; |
} |
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if (c->texture_2d_enabled) { |
q->tex_coord.X=p0->tex_coord.X + (p1->tex_coord.X-p0->tex_coord.X)*t; |
q->tex_coord.Y=p0->tex_coord.Y + (p1->tex_coord.Y-p0->tex_coord.Y)*t; |
} |
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q->clip_code=gl_clipcode(q->pc.X,q->pc.Y,q->pc.Z,q->pc.W); |
if (q->clip_code==0){ |
gl_transform_to_viewport(c,q); |
RGBFtoRGBI(q->color.v[0],q->color.v[1],q->color.v[2],q->zp.r,q->zp.g,q->zp.b); |
} |
} |
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static void gl_draw_triangle_clip(GLContext *c, |
GLVertex *p0,GLVertex *p1,GLVertex *p2,int clip_bit); |
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void gl_draw_triangle(GLContext *c, |
GLVertex *p0,GLVertex *p1,GLVertex *p2) |
{ |
int co,c_and,cc[3],front; |
float norm; |
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cc[0]=p0->clip_code; |
cc[1]=p1->clip_code; |
cc[2]=p2->clip_code; |
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co=cc[0] | cc[1] | cc[2]; |
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/* we handle the non clipped case here to go faster */ |
if (co==0) { |
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norm=(float)(p1->zp.x-p0->zp.x)*(float)(p2->zp.y-p0->zp.y)- |
(float)(p2->zp.x-p0->zp.x)*(float)(p1->zp.y-p0->zp.y); |
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if (norm == 0) return; |
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front = norm < 0.0; |
front = front ^ c->current_front_face; |
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/* back face culling */ |
if (c->cull_face_enabled) { |
/* most used case first */ |
if (c->current_cull_face == GL_BACK) { |
if (front == 0) return; |
c->draw_triangle_front(c,p0,p1,p2); |
} else if (c->current_cull_face == GL_FRONT) { |
if (front != 0) return; |
c->draw_triangle_back(c,p0,p1,p2); |
} else { |
return; |
} |
} else { |
/* no culling */ |
if (front) { |
c->draw_triangle_front(c,p0,p1,p2); |
} else { |
c->draw_triangle_back(c,p0,p1,p2); |
} |
} |
} else { |
c_and=cc[0] & cc[1] & cc[2]; |
if (c_and==0) { |
gl_draw_triangle_clip(c,p0,p1,p2,0); |
} |
} |
} |
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static void gl_draw_triangle_clip(GLContext *c, |
GLVertex *p0,GLVertex *p1,GLVertex *p2,int clip_bit) |
{ |
int co,c_and,co1,cc[3],edge_flag_tmp,clip_mask; |
GLVertex tmp1,tmp2,*q[3]; |
float tt; |
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cc[0]=p0->clip_code; |
cc[1]=p1->clip_code; |
cc[2]=p2->clip_code; |
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co=cc[0] | cc[1] | cc[2]; |
if (co == 0) { |
gl_draw_triangle(c,p0,p1,p2); |
} else { |
c_and=cc[0] & cc[1] & cc[2]; |
/* the triangle is completely outside */ |
if (c_and!=0) return; |
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/* find the next direction to clip */ |
while (clip_bit < 6 && (co & (1 << clip_bit)) == 0) { |
clip_bit++; |
} |
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/* this test can be true only in case of rounding errors */ |
if (clip_bit == 6) { |
#if 0 |
printf("Error:\n"); |
printf("%f %f %f %f\n",p0->pc.X,p0->pc.Y,p0->pc.Z,p0->pc.W); |
printf("%f %f %f %f\n",p1->pc.X,p1->pc.Y,p1->pc.Z,p1->pc.W); |
printf("%f %f %f %f\n",p2->pc.X,p2->pc.Y,p2->pc.Z,p2->pc.W); |
#endif |
return; |
} |
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clip_mask = 1 << clip_bit; |
co1=(cc[0] ^ cc[1] ^ cc[2]) & clip_mask; |
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if (co1) { |
/* one point outside */ |
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if (cc[0] & clip_mask) { q[0]=p0; q[1]=p1; q[2]=p2; } |
else if (cc[1] & clip_mask) { q[0]=p1; q[1]=p2; q[2]=p0; } |
else { q[0]=p2; q[1]=p0; q[2]=p1; } |
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tt=clip_proc[clip_bit](&tmp1.pc,&q[0]->pc,&q[1]->pc); |
updateTmp(c,&tmp1,q[0],q[1],tt); |
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tt=clip_proc[clip_bit](&tmp2.pc,&q[0]->pc,&q[2]->pc); |
updateTmp(c,&tmp2,q[0],q[2],tt); |
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tmp1.edge_flag=q[0]->edge_flag; |
edge_flag_tmp=q[2]->edge_flag; |
q[2]->edge_flag=0; |
gl_draw_triangle_clip(c,&tmp1,q[1],q[2],clip_bit+1); |
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tmp2.edge_flag=0; |
tmp1.edge_flag=0; |
q[2]->edge_flag=edge_flag_tmp; |
gl_draw_triangle_clip(c,&tmp2,&tmp1,q[2],clip_bit+1); |
} else { |
/* two points outside */ |
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if ((cc[0] & clip_mask)==0) { q[0]=p0; q[1]=p1; q[2]=p2; } |
else if ((cc[1] & clip_mask)==0) { q[0]=p1; q[1]=p2; q[2]=p0; } |
else { q[0]=p2; q[1]=p0; q[2]=p1; } |
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tt=clip_proc[clip_bit](&tmp1.pc,&q[0]->pc,&q[1]->pc); |
updateTmp(c,&tmp1,q[0],q[1],tt); |
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tt=clip_proc[clip_bit](&tmp2.pc,&q[0]->pc,&q[2]->pc); |
updateTmp(c,&tmp2,q[0],q[2],tt); |
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tmp1.edge_flag=1; |
tmp2.edge_flag=q[2]->edge_flag; |
gl_draw_triangle_clip(c,q[0],&tmp1,&tmp2,clip_bit+1); |
} |
} |
} |
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void gl_draw_triangle_select(GLContext *c, |
GLVertex *p0,GLVertex *p1,GLVertex *p2) |
{ |
gl_add_select1(c,p0->zp.z,p1->zp.z,p2->zp.z); |
} |
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#ifdef PROFILE |
int count_triangles,count_triangles_textured,count_pixels; |
#endif |
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void gl_draw_triangle_fill(GLContext *c, |
GLVertex *p0,GLVertex *p1,GLVertex *p2) |
{ |
#ifdef PROFILE |
{ |
int norm; |
assert(p0->zp.x >= 0 && p0->zp.x < c->zb->xsize); |
assert(p0->zp.y >= 0 && p0->zp.y < c->zb->ysize); |
assert(p1->zp.x >= 0 && p1->zp.x < c->zb->xsize); |
assert(p1->zp.y >= 0 && p1->zp.y < c->zb->ysize); |
assert(p2->zp.x >= 0 && p2->zp.x < c->zb->xsize); |
assert(p2->zp.y >= 0 && p2->zp.y < c->zb->ysize); |
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norm=(p1->zp.x-p0->zp.x)*(p2->zp.y-p0->zp.y)- |
(p2->zp.x-p0->zp.x)*(p1->zp.y-p0->zp.y); |
count_pixels+=abs(norm)/2; |
count_triangles++; |
} |
#endif |
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if (c->texture_2d_enabled) { |
#ifdef PROFILE |
count_triangles_textured++; |
#endif |
ZB_setTexture(c->zb,c->current_texture->images[0].pixmap); |
ZB_fillTriangleMappingPerspective(c->zb,&p0->zp,&p1->zp,&p2->zp); |
} else if (c->current_shade_model == GL_SMOOTH) { |
ZB_fillTriangleSmooth(c->zb,&p0->zp,&p1->zp,&p2->zp); |
} else { |
ZB_fillTriangleFlat(c->zb,&p0->zp,&p1->zp,&p2->zp); |
} |
} |
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/* Render a clipped triangle in line mode */ |
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void gl_draw_triangle_line(GLContext *c, |
GLVertex *p0,GLVertex *p1,GLVertex *p2) |
{ |
if (c->depth_test) { |
if (p0->edge_flag) ZB_line_z(c->zb,&p0->zp,&p1->zp); |
if (p1->edge_flag) ZB_line_z(c->zb,&p1->zp,&p2->zp); |
if (p2->edge_flag) ZB_line_z(c->zb,&p2->zp,&p0->zp); |
} else { |
if (p0->edge_flag) ZB_line(c->zb,&p0->zp,&p1->zp); |
if (p1->edge_flag) ZB_line(c->zb,&p1->zp,&p2->zp); |
if (p2->edge_flag) ZB_line(c->zb,&p2->zp,&p0->zp); |
} |
} |
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/* Render a clipped triangle in point mode */ |
void gl_draw_triangle_point(GLContext *c, |
GLVertex *p0,GLVertex *p1,GLVertex *p2) |
{ |
if (p0->edge_flag) ZB_plot(c->zb,&p0->zp); |
if (p1->edge_flag) ZB_plot(c->zb,&p1->zp); |
if (p2->edge_flag) ZB_plot(c->zb,&p2->zp); |
} |
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