/**
* Shade/write an array of quads
* Called via quad_stage::run()
*/
static void
shade_quads(struct quad_stage *qs,
struct quad_header *quads[],
unsigned nr)
{
struct softpipe_context *softpipe = qs->softpipe;
struct tgsi_exec_machine *machine = softpipe->fs_machine;
unsigned i, nr_quads = 0;
tgsi_exec_set_constant_buffers(machine, PIPE_MAX_CONSTANT_BUFFERS,
softpipe->mapped_constants[PIPE_SHADER_FRAGMENT],
softpipe->const_buffer_size[PIPE_SHADER_FRAGMENT]);
machine->InterpCoefs = quads[0]->coef;
for (i = 0; i < nr; i++) {
/* Only omit this quad from the output list if all the fragments
* are killed _AND_ it's not the first quad in the list.
* The first quad is special in the (optimized) depth-testing code:
* the quads' Z coordinates are step-wise interpolated with respect
* to the first quad in the list.
* For multi-pass algorithms we need to produce exactly the same
* Z values in each pass. If interpolation starts with different quads
* we can get different Z values for the same (x,y).
*/
if (!shade_quad(qs, quads[i]) && i > 0)
continue; /* quad totally culled/killed */
if (/*do_coverage*/ 0)
coverage_quad( qs, quads[i] );
quads[nr_quads++] = quads[i];
}
if (nr_quads)
qs->next->run(qs->next, quads, nr_quads);
}
void shade_bmap( double x0, double y0, float data0, float data1, double z0, double z1, int negative, double dev_x, double dev_y) /* apply current samples with all options to bitmap */
{
#define NPTS 4 /* 4 points for the general case here */
double xp[NPTS], yp[NPTS], temp, interp, slope01, slope02, slope12, slope13, slope23, slope03;
double slope0, slope1, slope2, slope3;
int ix, iy;
if (data0 == 0.0 && data1 == 0.0)return; /* probably shouldn't strictly, but pathological enough I dont really want to deal with it! */
interp = 0.0;
if ((data0*data1)<0.0){
/* points to plot are on different sides of zero - interpolate to find out where zero is */
interp=z0+data0*((z0-z1)/(data1-data0));
if(((data0<0.0) && negative) || ((data0>0.0)&& !negative)) {
/* plot from top to zero */
z1=interp;
data1=0.0;
}
else {
z0=interp;
data0=0.0;
}
}
GMT_geoz_to_xy (x0+(double)data0*dev_x, y0+(double)data0*dev_y, z0, &xp[0], &yp[0]); /* returns 2 ends of line segment in plot coords */
GMT_geoz_to_xy (x0+(double)data1*dev_x, y0+(double)data1*dev_y, z1, &xp[1], &yp[1]);
GMT_geoz_to_xy (x0, y0, z0, &xp[2], &yp[2]); /* to get position of zero at each point*/
GMT_geoz_to_xy (x0, y0, z1, &xp[3], &yp[3]); /* to get position of zero at each point*/
/* now have four corner coordinates - need to sort them */
for (ix=0; ix<NPTS-1; ix++)
for (iy=ix+1; iy<NPTS; iy++)
if(yp[ix]>yp[iy]){
temp = yp[iy];
yp[iy]=yp[ix];
yp[ix]=temp;
temp = xp[iy];
xp[iy]=xp[ix];
xp[ix]=temp;
}
/* have to fill the quadrilateral defined by 4 points (now ordered, but care with degenerate cases)*/
slope01 = (xp[1]-xp[0])/(yp[1]-yp[0]);
slope02 = (xp[2]-xp[0])/(yp[2]-yp[0]);
slope12 = (xp[2]-xp[1])/(yp[2]-yp[1]);
slope13 = (xp[3]-xp[1])/(yp[3]-yp[1]);
slope23 = (xp[3]-xp[2])/(yp[3]-yp[2]);
slope03 = (xp[3]-xp[0])/(yp[3]-yp[0]);
if ((yp[0]!=yp[1]) && (yp[2]!=yp[3])){ /* simple case: tri-quad-tri */
shade_tri(xp[0], yp[0], yp[1], slope01, slope02);
shade_quad(xp[1], yp[1],xp[0]+slope02*(yp[1]-yp[0]), yp[2], slope02, slope13);
shade_tri(xp[3], yp[3], yp[2], slope13, slope23);
}
if ((yp[0]==yp[1]) && (yp[2]!=yp[3])){
if (xp[0]==xp[1]){ /* two triangles based on yp[1],yp[2]. yp[3] */
shade_tri(xp[1], yp[1], yp[2], slope12, slope13);
shade_tri(xp[3], yp[3], yp[2], slope23, slope13);
}else{ /* quad based on first 3 points, then tri */
slope0 = (((xp[0]<xp[1]) && (xp[3]<xp[2])) || ((xp[0]>xp[1])&&(xp[3]>xp[2])))*slope03 + (((xp[0]<xp[1])&&(xp[2]<xp[3])) || ((xp[0]>xp[1])&&(xp[2]>xp[3])))*slope02;
slope1 = (((xp[1]<xp[0]) && (xp[3]<xp[2])) || ((xp[1]>xp[0]) && (xp[3]>xp[2])))*slope13 + (((xp[1]<xp[0])&&(xp[2]<xp[3])) || ((xp[1]>xp[0])&&(xp[2]>xp[3])))*slope12;
slope3 = (((xp[1]<xp[0]) && (xp[3]<xp[2])) || ((xp[1]>xp[0]) && (xp[3]>xp[2])))*slope13 + (((xp[0]<xp[1])&&(xp[3]<xp[2])) || ((xp[0]>xp[1])&&(xp[3]>xp[2])))*slope03;
shade_quad(xp[0], yp[0], xp[1], yp[2], slope0, slope1);
shade_tri(xp[3], yp[3], yp[2], slope23, slope3);
}
}
if ((yp[0]!=yp[1]) && (yp[2]==yp[3])){
if(xp[2]==xp[3]){/* two triangles based on yp[0],yp[1]. yp[2] */
shade_tri(xp[0], yp[0], yp[1], slope01, slope02);
shade_tri(xp[2], yp[2], yp[1], slope12, slope02);
}else{ /* triangle based on yp[0], yp[1], then quad based on last 3 points */
slope0 = (((xp[0]<xp[1]) && (xp[3]<xp[2])) || ((xp[0]>xp[1]) && (xp[3]>xp[2])))*slope03 + (((xp[0]<xp[1])&&(xp[2]<xp[3])) || ((xp[0]>xp[1])&&(xp[2]>xp[3])))*slope02;
shade_tri(xp[0], yp[0], yp[1], slope01, slope0);
slope2 = (((xp[0]<xp[1]) && (xp[2]<xp[3])) || ((xp[0]>xp[1]) && (xp[2]>xp[3])))*slope02 + (((xp[0]<xp[1]) && (xp[3]<xp[2])) || ((xp[0]>xp[1]) && (xp[3]>xp[2])))*slope12;
slope3 = (((xp[0]<xp[1]) && (xp[3]<xp[2])) || ((xp[0]>xp[1]) && (xp[3]>xp[2])))*slope03 + (((xp[0]<xp[1]) && (xp[2]<xp[3])) ||
((xp[0]>xp[1]) && (xp[2]>xp[3])))*slope13;
shade_quad(xp[2], yp[2], xp[3], yp[1], slope2, slope3);
}
}
}
