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author | inmarket <andrewh@inmarket.com.au> | 2014-08-20 17:44:40 +1000 |
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committer | inmarket <andrewh@inmarket.com.au> | 2014-08-20 17:44:40 +1000 |
commit | 2b47a0708602b45b0b5db120a496bf92232aa4b1 (patch) | |
tree | 6c5965b6bf1d109b853efe64777bbc7ee5548882 /3rdparty/tinygl-0.4-ugfx/src/clip.c | |
parent | c06bff3304ed234c3a7f96fd049755ac59228ef7 (diff) | |
parent | 0f3f8f68f87233bf59c3fa68c3dfe1f492a1a478 (diff) | |
download | uGFX-2b47a0708602b45b0b5db120a496bf92232aa4b1.tar.gz uGFX-2b47a0708602b45b0b5db120a496bf92232aa4b1.tar.bz2 uGFX-2b47a0708602b45b0b5db120a496bf92232aa4b1.zip |
Merge branch 'master' into newmouse
Diffstat (limited to '3rdparty/tinygl-0.4-ugfx/src/clip.c')
-rw-r--r-- | 3rdparty/tinygl-0.4-ugfx/src/clip.c | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/3rdparty/tinygl-0.4-ugfx/src/clip.c b/3rdparty/tinygl-0.4-ugfx/src/clip.c new file mode 100644 index 00000000..47481fa3 --- /dev/null +++ b/3rdparty/tinygl-0.4-ugfx/src/clip.c @@ -0,0 +1,445 @@ +#include "zgl.h" + +/* fill triangle profile */ +/* #define PROFILE */ + +#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) + +void gl_transform_to_viewport(GLContext *c,GLVertex *v) +{ + float winv; + + /* 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]; + } + + /* texture */ + + 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); + } +} + + +static void gl_add_select1(GLContext *c,int z1,int z2,int z3) +{ + unsigned int min,max; + min=max=z1; + if ((unsigned int)z2<min) min=z2; + if ((unsigned int)z3<min) min=z3; + if ((unsigned int)z2>max) max=z2; + if ((unsigned int)z3>max) max=z3; + + gl_add_select(c,0xffffffff-min,0xffffffff-max); +} + +/* point */ + +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); + } + } +} + +/* line */ + +static inline void line_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; + + 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; +} + +/* + * Line Clipping + */ + +/* Line Clipping algorithm from 'Computer Graphics', Principles and + Practice */ +static inline int ClipLine1(float denom,float num,float *tmin,float *tmax) +{ + float t; + + 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; +} + +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; + + cc1=p1->clip_code; + cc2=p2->clip_code; + + 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; + + 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)) { + + line_interpolate(&q1,p1,p2,tmin); + line_interpolate(&q2,p1,p2,tmax); + gl_transform_to_viewport(c,&q1); + gl_transform_to_viewport(c,&q2); + + if (c->depth_test) + ZB_line_z(c->zb,&q1.zp,&q2.zp); + else + ZB_line(c->zb,&q1.zp,&q2.zp); + } + } +} + + +/* triangle */ + +/* + * Clipping + */ + +/* 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). + */ + +#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;\ +} + + +clip_func(clip_xmin,-,X,Y,Z) + +clip_func(clip_xmax,+,X,Y,Z) + +clip_func(clip_ymin,-,Y,X,Z) + +clip_func(clip_ymax,+,Y,X,Z) + +clip_func(clip_zmin,-,Z,X,Y) + +clip_func(clip_zmax,+,Z,X,Y) + + +float (*clip_proc[6])(V4 *,V4 *,V4 *)= { + clip_xmin,clip_xmax, + clip_ymin,clip_ymax, + clip_zmin,clip_zmax +}; + +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]; + } + + 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; + } + + 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); +} + +static void gl_draw_triangle_clip(GLContext *c, + GLVertex *p0,GLVertex *p1,GLVertex *p2,int clip_bit); + +void gl_draw_triangle(GLContext *c, + GLVertex *p0,GLVertex *p1,GLVertex *p2) +{ + int co,c_and,cc[3],front; + float norm; + + cc[0]=p0->clip_code; + cc[1]=p1->clip_code; + cc[2]=p2->clip_code; + + co=cc[0] | cc[1] | cc[2]; + + /* we handle the non clipped case here to go faster */ + if (co==0) { + + 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); + + if (norm == 0) return; + + front = norm < 0.0; + front = front ^ c->current_front_face; + + /* 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); + } + } +} + +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; + + cc[0]=p0->clip_code; + cc[1]=p1->clip_code; + cc[2]=p2->clip_code; + + 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; + + /* find the next direction to clip */ + while (clip_bit < 6 && (co & (1 << clip_bit)) == 0) { + clip_bit++; + } + + /* 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; + } + + clip_mask = 1 << clip_bit; + co1=(cc[0] ^ cc[1] ^ cc[2]) & clip_mask; + + if (co1) { + /* one point outside */ + + 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; } + + tt=clip_proc[clip_bit](&tmp1.pc,&q[0]->pc,&q[1]->pc); + updateTmp(c,&tmp1,q[0],q[1],tt); + + tt=clip_proc[clip_bit](&tmp2.pc,&q[0]->pc,&q[2]->pc); + updateTmp(c,&tmp2,q[0],q[2],tt); + + 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); + + tmp2.edge_flag=1; + 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 */ + + 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; } + + tt=clip_proc[clip_bit](&tmp1.pc,&q[0]->pc,&q[1]->pc); + updateTmp(c,&tmp1,q[0],q[1],tt); + + tt=clip_proc[clip_bit](&tmp2.pc,&q[0]->pc,&q[2]->pc); + updateTmp(c,&tmp2,q[0],q[2],tt); + + tmp1.edge_flag=1; + tmp2.edge_flag=q[2]->edge_flag; + gl_draw_triangle_clip(c,q[0],&tmp1,&tmp2,clip_bit+1); + } + } +} + + +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); +} + +#ifdef PROFILE +int count_triangles,count_triangles_textured,count_pixels; +#endif + +void gl_draw_triangle_fill(GLContext *c, + GLVertex *p0,GLVertex *p1,GLVertex *p2) +{ +#ifdef PROFILE + { + int norm; + gl_assert(p0->zp.x >= 0 && p0->zp.x < c->zb->xsize); + gl_assert(p0->zp.y >= 0 && p0->zp.y < c->zb->ysize); + gl_assert(p1->zp.x >= 0 && p1->zp.x < c->zb->xsize); + gl_assert(p1->zp.y >= 0 && p1->zp.y < c->zb->ysize); + gl_assert(p2->zp.x >= 0 && p2->zp.x < c->zb->xsize); + gl_assert(p2->zp.y >= 0 && p2->zp.y < c->zb->ysize); + + 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 + + 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); + } +} + +/* Render a clipped triangle in line mode */ + +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); + } +} + + + +/* 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); +} + + + + |