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diff --git a/src/mesa/pipe/softpipe/sp_prim_setup.c b/src/mesa/pipe/softpipe/sp_prim_setup.c
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+/**************************************************************************
+ *
+ * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+/* Authors: Keith Whitwell <keith@tungstengraphics.com>
+ */
+
+#include "imports.h"
+#include "macros.h"
+
+#include "sp_context.h"
+#include "sp_prim.h"
+#include "sp_tile.h"
+
+
+/**
+ * Triangle edge info
+ */
+struct edge {
+ GLfloat dx; /* X(v1) - X(v0), used only during setup */
+ GLfloat dy; /* Y(v1) - Y(v0), used only during setup */
+ GLfloat dxdy; /* dx/dy */
+ GLfloat sx; /* first sample point x coord */
+ GLfloat sy;
+ GLint lines; /* number of lines on this edge */
+};
+
+
+/**
+ * Triangle setup info (derived from prim_stage).
+ * Also used for line drawing (taking some liberties).
+ */
+struct setup_stage {
+ struct prim_stage stage; /**< This must be first */
+
+ /* Vertices are just an array of floats making up each attribute in
+ * turn. Currently fixed at 4 floats, but should change in time.
+ * Codegen will help cope with this.
+ */
+ const struct vertex_header *vmax;
+ const struct vertex_header *vmid;
+ const struct vertex_header *vmin;
+ const struct vertex_header *vprovoke;
+
+ struct edge ebot;
+ struct edge etop;
+ struct edge emaj;
+
+ GLfloat oneoverarea;
+
+ struct setup_coefficient coef[FRAG_ATTRIB_MAX];
+ struct quad_header quad;
+
+ struct {
+ GLint left[2]; /**< [0] = row0, [1] = row1 */
+ GLint right[2];
+ GLint y;
+ GLuint y_flags;
+ GLuint mask; /**< mask of MASK_BOTTOM/TOP_LEFT/RIGHT bits */
+ } span;
+};
+
+
+
+/**
+ * Basically a cast wrapper.
+ */
+static inline struct setup_stage *setup_stage( struct prim_stage *stage )
+{
+ return (struct setup_stage *)stage;
+}
+
+
+/**
+ * Given an X or Y coordinate, return the block/quad coordinate that it
+ * belongs to.
+ */
+static inline GLint block( GLint x )
+{
+ return x & ~1;
+}
+
+
+
+static void setup_begin( struct prim_stage *stage )
+{
+ setup_stage(stage)->quad.nr_attrs = stage->softpipe->nr_frag_attrs;
+}
+
+
+/**
+ * Run shader on a quad/block.
+ */
+static void run_shader_block( struct setup_stage *setup,
+ GLint x, GLint y, GLuint mask )
+{
+ setup->quad.x0 = x;
+ setup->quad.y0 = y;
+ setup->quad.mask = mask;
+
+ quad_shade( setup->stage.softpipe, &setup->quad );
+}
+
+
+/**
+ * Compute mask which indicates which pixels in the 2x2 quad are actually inside
+ * the triangle's bounds.
+ *
+ * this is pretty nasty... may need to rework flush_spans again to
+ * fix it, if possible.
+ */
+static GLuint calculate_mask( struct setup_stage *setup,
+ GLint x )
+{
+ GLuint mask = 0;
+
+ if (x >= setup->span.left[0] && x < setup->span.right[0])
+ mask |= MASK_BOTTOM_LEFT;
+
+ if (x >= setup->span.left[1] && x < setup->span.right[1])
+ mask |= MASK_TOP_LEFT;
+
+ if (x+1 >= setup->span.left[0] && x+1 < setup->span.right[0])
+ mask |= MASK_BOTTOM_RIGHT;
+
+ if (x+1 >= setup->span.left[1] && x+1 < setup->span.right[1])
+ mask |= MASK_TOP_RIGHT;
+
+ return mask;
+}
+
+
+/**
+ * Render a horizontal span of quads
+ */
+static void flush_spans( struct setup_stage *setup )
+{
+ GLint minleft, maxright;
+ GLint x;
+
+ switch (setup->span.y_flags) {
+ case 3:
+ minleft = MIN2(setup->span.left[0], setup->span.left[1]);
+ maxright = MAX2(setup->span.right[0], setup->span.right[1]);
+ break;
+
+ case 1:
+ minleft = setup->span.left[0];
+ maxright = setup->span.right[0];
+ break;
+
+ case 2:
+ minleft = setup->span.left[1];
+ maxright = setup->span.right[1];
+ break;
+
+ default:
+ return;
+ }
+
+
+ for (x = block(minleft); x <= block(maxright); )
+ {
+ run_shader_block( setup, x,
+ setup->span.y,
+ calculate_mask( setup, x ) );
+ x += 2;
+ }
+
+ setup->span.y = 0;
+ setup->span.y_flags = 0;
+ setup->span.right[0] = 0;
+ setup->span.right[1] = 0;
+}
+
+
+static GLboolean setup_sort_vertices( struct setup_stage *setup,
+ const struct prim_header *prim )
+{
+ const struct vertex_header *v0 = prim->v[0];
+ const struct vertex_header *v1 = prim->v[1];
+ const struct vertex_header *v2 = prim->v[2];
+
+ setup->vprovoke = v2;
+
+ /* determine bottom to top order of vertices */
+ {
+ GLfloat y0 = v0->data[0][1];
+ GLfloat y1 = v1->data[0][1];
+ GLfloat y2 = v2->data[0][1];
+ if (y0 <= y1) {
+ if (y1 <= y2) {
+ /* y0<=y1<=y2 */
+ setup->vmin = v0;
+ setup->vmid = v1;
+ setup->vmax = v2;
+ }
+ else if (y2 <= y0) {
+ /* y2<=y0<=y1 */
+ setup->vmin = v2;
+ setup->vmid = v0;
+ setup->vmax = v1;
+ }
+ else {
+ /* y0<=y2<=y1 */
+ setup->vmin = v0;
+ setup->vmid = v2;
+ setup->vmax = v1;
+ }
+ }
+ else {
+ if (y0 <= y2) {
+ /* y1<=y0<=y2 */
+ setup->vmin = v1;
+ setup->vmid = v0;
+ setup->vmax = v2;
+ }
+ else if (y2 <= y1) {
+ /* y2<=y1<=y0 */
+ setup->vmin = v2;
+ setup->vmid = v1;
+ setup->vmax = v0;
+ }
+ else {
+ /* y1<=y2<=y0 */
+ setup->vmin = v1;
+ setup->vmid = v2;
+ setup->vmax = v0;
+ }
+ }
+ }
+
+ setup->ebot.dx = setup->vmid->data[0][0] - setup->vmin->data[0][0];
+ setup->ebot.dy = setup->vmid->data[0][1] - setup->vmin->data[0][1];
+ setup->emaj.dx = setup->vmax->data[0][0] - setup->vmin->data[0][0];
+ setup->emaj.dy = setup->vmax->data[0][1] - setup->vmin->data[0][1];
+ setup->etop.dx = setup->vmax->data[0][0] - setup->vmid->data[0][0];
+ setup->etop.dy = setup->vmax->data[0][1] - setup->vmid->data[0][1];
+
+ /* xxx: may need to adjust this sign according to the if-tree
+ * above:
+ *
+ * XXX: this is like 'det', but calculated from screen coords??
+ */
+ {
+ const GLfloat area = (setup->emaj.dx * setup->ebot.dy -
+ setup->ebot.dx * setup->emaj.dy);
+
+ setup->oneoverarea = 1.0 / area;
+ }
+
+ /* XXX need to know if this is a front or back-facing triangle:
+ * - the GLSL gl_FrontFacing fragment attribute (bool)
+ * - two-sided stencil test
+ */
+ setup->quad.facing = 0;
+
+ _mesa_printf("%s one-over-area %f\n", __FUNCTION__, setup->oneoverarea );
+
+
+ return GL_TRUE;
+}
+
+
+/**
+ * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
+ */
+static void const_coeff( struct setup_stage *setup,
+ GLuint slot,
+ GLuint i )
+{
+ setup->coef[slot].dadx[i] = 0;
+ setup->coef[slot].dady[i] = 0;
+
+ /* need provoking vertex info!
+ */
+ setup->coef[slot].a0[i] = setup->vprovoke->data[slot][i];
+}
+
+
+/**
+ * Compute a0, dadx and dady for a linearly interpolated coefficient,
+ * for a triangle.
+ */
+static void tri_linear_coeff( struct setup_stage *setup,
+ GLuint slot,
+ GLuint i)
+{
+ GLfloat botda = setup->vmid->data[slot][i] - setup->vmin->data[slot][i];
+ GLfloat majda = setup->vmax->data[slot][i] - setup->vmin->data[slot][i];
+ GLfloat a = setup->ebot.dy * majda - botda * setup->emaj.dy;
+ GLfloat b = setup->emaj.dx * botda - majda * setup->ebot.dx;
+
+ setup->coef[slot].dadx[i] = a * setup->oneoverarea;
+ setup->coef[slot].dady[i] = b * setup->oneoverarea;
+
+ /* calculate a0 as the value which would be sampled for the
+ * fragment at (0,0), taking into account that we want to sample at
+ * pixel centers, in other words (0.5, 0.5).
+ *
+ * this is neat but unfortunately not a good way to do things for
+ * triangles with very large values of dadx or dady as it will
+ * result in the subtraction and re-addition from a0 of a very
+ * large number, which means we'll end up loosing a lot of the
+ * fractional bits and precision from a0. the way to fix this is
+ * to define a0 as the sample at a pixel center somewhere near vmin
+ * instead - i'll switch to this later.
+ */
+ setup->coef[slot].a0[i] = (setup->vmin->data[slot][i] -
+ (setup->coef[slot].dadx[i] * (setup->vmin->data[0][0] - 0.5) +
+ setup->coef[slot].dady[i] * (setup->vmin->data[0][1] - 0.5)));
+
+ _mesa_printf("attr[%d].%c: %f dx:%f dy:%f\n",
+ slot, "xyzw"[i],
+ setup->coef[slot].a0[i],
+ setup->coef[slot].dadx[i],
+ setup->coef[slot].dady[i]);
+}
+
+
+/**
+ * Compute a0, dadx and dady for a perspective-corrected interpolant,
+ * for a triangle.
+ */
+static void tri_persp_coeff( struct setup_stage *setup,
+ GLuint slot,
+ GLuint i )
+{
+ /* premultiply by 1/w:
+ */
+ GLfloat mina = setup->vmin->data[slot][i] * setup->vmin->data[0][3];
+ GLfloat mida = setup->vmid->data[slot][i] * setup->vmid->data[0][3];
+ GLfloat maxa = setup->vmax->data[slot][i] * setup->vmax->data[0][3];
+
+ GLfloat botda = mida - mina;
+ GLfloat majda = maxa - mina;
+ GLfloat a = setup->ebot.dy * majda - botda * setup->emaj.dy;
+ GLfloat b = setup->emaj.dx * botda - majda * setup->ebot.dx;
+
+ setup->coef[slot].dadx[i] = a * setup->oneoverarea;
+ setup->coef[slot].dady[i] = b * setup->oneoverarea;
+ setup->coef[slot].a0[i] = (mina -
+ (setup->coef[slot].dadx[i] * (setup->vmin->data[0][0] - 0.5) +
+ setup->coef[slot].dady[i] * (setup->vmin->data[0][1] - 0.5)));
+}
+
+
+
+/**
+ * Compute the setup->coef[] array dadx, dady, a0 values.
+ * Must be called after setup->vmin,vmid,vmax,vprovoke are initialized.
+ */
+static void setup_tri_coefficients( struct setup_stage *setup )
+{
+ const enum interp_mode *interp = setup->stage.softpipe->interp;
+ GLuint slot, j;
+
+ /* z and w are done by linear interpolation:
+ */
+ tri_linear_coeff(setup, 0, 2);
+ tri_linear_coeff(setup, 0, 3);
+
+ /* setup interpolation for all the remaining attributes:
+ */
+ for (slot = 1; slot < setup->quad.nr_attrs; slot++) {
+ switch (interp[slot]) {
+ case INTERP_CONSTANT:
+ for (j = 0; j < NUM_CHANNELS; j++)
+ const_coeff(setup, slot, j);
+ break;
+
+ case INTERP_LINEAR:
+ for (j = 0; j < NUM_CHANNELS; j++)
+ tri_linear_coeff(setup, slot, j);
+ break;
+
+ case INTERP_PERSPECTIVE:
+ for (j = 0; j < NUM_CHANNELS; j++)
+ tri_persp_coeff(setup, slot, j);
+ break;
+ }
+ }
+}
+
+
+
+static void setup_tri_edges( struct setup_stage *setup )
+{
+ GLfloat vmin_x = setup->vmin->data[0][0] + 0.5;
+ GLfloat vmid_x = setup->vmid->data[0][0] + 0.5;
+
+ GLfloat vmin_y = setup->vmin->data[0][1] - 0.5;
+ GLfloat vmid_y = setup->vmid->data[0][1] - 0.5;
+ GLfloat vmax_y = setup->vmax->data[0][1] - 0.5;
+
+ setup->emaj.sy = ceilf(vmin_y);
+ setup->emaj.lines = (GLint) ceilf(vmax_y - setup->emaj.sy);
+ setup->emaj.dxdy = setup->emaj.dx / setup->emaj.dy;
+ setup->emaj.sx = vmin_x + (setup->emaj.sy - vmin_y) * setup->emaj.dxdy;
+
+ setup->etop.sy = ceilf(vmid_y);
+ setup->etop.lines = (GLint) ceilf(vmax_y - setup->etop.sy);
+ setup->etop.dxdy = setup->etop.dx / setup->etop.dy;
+ setup->etop.sx = vmid_x + (setup->etop.sy - vmid_y) * setup->etop.dxdy;
+
+ setup->ebot.sy = ceilf(vmin_y);
+ setup->ebot.lines = (GLint) ceilf(vmid_y - setup->ebot.sy);
+ setup->ebot.dxdy = setup->ebot.dx / setup->ebot.dy;
+ setup->ebot.sx = vmin_x + (setup->ebot.sy - vmin_y) * setup->ebot.dxdy;
+}
+
+
+/**
+ * Render the upper or lower half of a triangle.
+ * Scissoring is applied here too.
+ */
+static void subtriangle( struct setup_stage *setup,
+ struct edge *eleft,
+ struct edge *eright,
+ GLuint lines )
+{
+ GLint y, start_y, finish_y;
+ GLint sy = (GLint)eleft->sy;
+
+ assert((GLint)eleft->sy == (GLint) eright->sy);
+ assert((GLint)eleft->sy >= 0); /* catch bug in x64? */
+
+ /* scissor y:
+ */
+ if (setup->stage.softpipe->setup.scissor) {
+ start_y = sy;
+ finish_y = start_y + lines;
+
+ if (start_y < setup->stage.softpipe->scissor.miny)
+ start_y = setup->stage.softpipe->scissor.miny;
+
+ if (finish_y > setup->stage.softpipe->scissor.maxy)
+ finish_y = setup->stage.softpipe->scissor.maxy;
+
+ start_y -= sy;
+ finish_y -= sy;
+ }
+ else {
+ start_y = 0;
+ finish_y = lines;
+ }
+
+ _mesa_printf("%s %d %d\n", __FUNCTION__, start_y, finish_y);
+
+ for (y = start_y; y < finish_y; y++) {
+
+ /* avoid accumulating adds as floats don't have the precision to
+ * accurately iterate large triangle edges that way. luckily we
+ * can just multiply these days.
+ *
+ * this is all drowned out by the attribute interpolation anyway.
+ */
+ GLint left = (GLint)(eleft->sx + y * eleft->dxdy);
+ GLint right = (GLint)(eright->sx + y * eright->dxdy);
+
+ /* scissor x:
+ */
+ if (setup->stage.softpipe->setup.scissor) {
+ if (left < setup->stage.softpipe->scissor.minx)
+ left = setup->stage.softpipe->scissor.minx;
+
+ if (right > setup->stage.softpipe->scissor.maxx)
+ right = setup->stage.softpipe->scissor.maxx;
+ }
+
+ if (left < right) {
+ GLint _y = sy+y;
+ if (block(_y) != setup->span.y) {
+ flush_spans(setup);
+ setup->span.y = block(_y);
+ }
+
+ setup->span.left[_y&1] = left;
+ setup->span.right[_y&1] = right;
+ setup->span.y_flags |= 1<<(_y&1);
+ }
+ }
+
+
+ /* save the values so that emaj can be restarted:
+ */
+ eleft->sx += lines * eleft->dxdy;
+ eright->sx += lines * eright->dxdy;
+ eleft->sy += lines;
+ eright->sy += lines;
+}
+
+
+/**
+ * Do setup for triangle rasterization, then render the triangle.
+ */
+static void setup_tri( struct prim_stage *stage,
+ struct prim_header *prim )
+{
+ struct setup_stage *setup = setup_stage( stage );
+
+ _mesa_printf("%s\n", __FUNCTION__ );
+
+ setup_sort_vertices( setup, prim );
+ setup_tri_coefficients( setup );
+ setup_tri_edges( setup );
+
+ setup->span.y = 0;
+ setup->span.y_flags = 0;
+ setup->span.right[0] = 0;
+ setup->span.right[1] = 0;
+// setup->span.z_mode = tri_z_mode( setup->ctx );
+
+// init_constant_attribs( setup );
+
+ if (setup->oneoverarea < 0.0) {
+ /* emaj on left:
+ */
+ subtriangle( setup, &setup->emaj, &setup->ebot, setup->ebot.lines );
+ subtriangle( setup, &setup->emaj, &setup->etop, setup->etop.lines );
+ }
+ else {
+ /* emaj on right:
+ */
+ subtriangle( setup, &setup->ebot, &setup->emaj, setup->ebot.lines );
+ subtriangle( setup, &setup->etop, &setup->emaj, setup->etop.lines );
+ }
+
+ flush_spans( setup );
+}
+
+
+
+/**
+ * Compute a0, dadx and dady for a linearly interpolated coefficient,
+ * for a line.
+ */
+static void
+line_linear_coeff(struct setup_stage *setup, GLuint slot, GLuint i)
+{
+ const GLfloat dz = setup->vmax->data[slot][i] - setup->vmin->data[slot][i];
+ const GLfloat dadx = dz * setup->emaj.dx * setup->oneoverarea;
+ const GLfloat dady = dz * setup->emaj.dy * setup->oneoverarea;
+ setup->coef[slot].dadx[i] = dadx;
+ setup->coef[slot].dady[i] = dady;
+ setup->coef[slot].a0[i]
+ = (setup->vmin->data[slot][i] -
+ (dadx * (setup->vmin->data[0][0] - 0.5) +
+ dady * (setup->vmin->data[0][1] - 0.5)));
+}
+
+
+/**
+ * Compute a0, dadx and dady for a perspective-corrected interpolant,
+ * for a line.
+ */
+static void
+line_persp_coeff(struct setup_stage *setup, GLuint slot, GLuint i)
+{
+ /* XXX to do */
+ line_linear_coeff(setup, slot, i); /* XXX temporary */
+}
+
+
+/**
+ * Compute the setup->coef[] array dadx, dady, a0 values.
+ * Must be called after setup->vmin,vmax are initialized.
+ */
+static INLINE void
+setup_line_coefficients(struct setup_stage *setup, struct prim_header *prim)
+{
+ const enum interp_mode *interp = setup->stage.softpipe->interp;
+ GLuint slot, j;
+
+ /* use setup->vmin, vmax to point to vertices */
+ setup->vprovoke = prim->v[1];
+ setup->vmin = prim->v[0];
+ setup->vmax = prim->v[1];
+
+ setup->emaj.dx = setup->vmax->data[0][0] - setup->vmin->data[0][0];
+ setup->emaj.dy = setup->vmax->data[0][1] - setup->vmin->data[0][1];
+ /* NOTE: this is not really 1/area */
+ setup->oneoverarea = 1.0 / (setup->emaj.dx * setup->emaj.dx +
+ setup->emaj.dy * setup->emaj.dy);
+
+ /* z and w are done by linear interpolation:
+ */
+ line_linear_coeff(setup, 0, 2);
+ line_linear_coeff(setup, 0, 3);
+
+ /* setup interpolation for all the remaining attributes:
+ */
+ for (slot = 1; slot < setup->quad.nr_attrs; slot++) {
+ switch (interp[slot]) {
+ case INTERP_CONSTANT:
+ for (j = 0; j < NUM_CHANNELS; j++)
+ const_coeff(setup, slot, j);
+ break;
+
+ case INTERP_LINEAR:
+ for (j = 0; j < NUM_CHANNELS; j++)
+ line_linear_coeff(setup, slot, j);
+ break;
+
+ case INTERP_PERSPECTIVE:
+ for (j = 0; j < NUM_CHANNELS; j++)
+ line_persp_coeff(setup, slot, j);
+ break;
+ }
+ }
+}
+
+
+/**
+ * Plot a pixel in a line segment.
+ */
+static INLINE void
+plot(struct setup_stage *setup, GLint x, GLint y)
+{
+ const GLint iy = y & 1;
+ const GLint ix = x & 1;
+ const GLint quadX = x - ix;
+ const GLint quadY = y - iy;
+ const GLint mask = (1 << ix) << (2 * iy);
+
+ if (quadX != setup->quad.x0 ||
+ quadY != setup->quad.y0)
+ {
+ /* flush prev quad, start new quad */
+
+ if (setup->quad.x0 != -1)
+ quad_shade(setup->stage.softpipe, &setup->quad);
+
+ setup->quad.x0 = quadX;
+ setup->quad.y0 = quadY;
+ setup->quad.mask = 0x0;
+ }
+
+ setup->quad.mask |= mask;
+}
+
+
+
+/**
+ * Do setup for line rasterization, then render the line.
+ * XXX single-pixel width, no stipple, etc
+ * XXX no scissoring yet.
+ */
+static void
+setup_line(struct prim_stage *stage, struct prim_header *prim)
+{
+ const struct vertex_header *v0 = prim->v[0];
+ const struct vertex_header *v1 = prim->v[1];
+ struct setup_stage *setup = setup_stage( stage );
+
+ GLint x0 = (GLint) v0->data[0][0];
+ GLint x1 = (GLint) v1->data[0][0];
+ GLint y0 = (GLint) v0->data[0][1];
+ GLint y1 = (GLint) v1->data[0][1];
+ GLint dx = x1 - x0;
+ GLint dy = y1 - y0;
+ GLint xstep, ystep;
+
+ if (dx == 0 && dy == 0)
+ return;
+
+ setup_line_coefficients(setup, prim);
+
+ if (dx < 0) {
+ dx = -dx; /* make positive */
+ xstep = -1;
+ }
+ else {
+ xstep = 1;
+ }
+
+ if (dy < 0) {
+ dy = -dy; /* make positive */
+ ystep = -1;
+ }
+ else {
+ ystep = 1;
+ }
+
+ assert(dx >= 0);
+ assert(dy >= 0);
+
+ setup->quad.x0 = setup->quad.y0 = -1;
+ setup->quad.mask = 0x0;
+
+ if (dx > dy) {
+ /*** X-major line ***/
+ GLint i;
+ const GLint errorInc = dy + dy;
+ GLint error = errorInc - dx;
+ const GLint errorDec = error - dx;
+
+ for (i = 0; i < dx; i++) {
+ plot(setup, x0, y0);
+
+ x0 += xstep;
+ if (error < 0) {
+ error += errorInc;
+ }
+ else {
+ error += errorDec;
+ y0 += ystep;
+ }
+ }
+ }
+ else {
+ /*** Y-major line ***/
+ GLint i;
+ const GLint errorInc = dx + dx;
+ GLint error = errorInc - dy;
+ const GLint errorDec = error - dy;
+
+ for (i = 0; i < dy; i++) {
+ plot(setup, x0, y0);
+
+ y0 += ystep;
+
+ if (error < 0) {
+ error += errorInc;
+ }
+ else {
+ error += errorDec;
+ x0 += xstep;
+ }
+ }
+ }
+
+ /* draw final quad */
+ if (setup->quad.mask) {
+ quad_shade(setup->stage.softpipe, &setup->quad);
+ }
+}
+
+
+/**
+ * Do setup for point rasterization, then render the point.
+ * Round or square points...
+ * XXX could optimize a lot for 1-pixel points.
+ */
+static void
+setup_point(struct prim_stage *stage, struct prim_header *prim)
+{
+ struct setup_stage *setup = setup_stage( stage );
+ GLfloat halfSize = 7.3; /*XXX this is a vertex attrib */
+ GLfloat halfSizeSquared = halfSize * halfSize;
+ const struct vertex_header *v0 = prim->v[0];
+ const GLfloat x = v0->data[FRAG_ATTRIB_WPOS][0];
+ const GLfloat y = v0->data[FRAG_ATTRIB_WPOS][1];
+ const GLint ixmin = block((GLint) (x - halfSize));
+ const GLint ixmax = block((GLint) (x + halfSize));
+ const GLint iymin = block((GLint) (y - halfSize));
+ const GLint iymax = block((GLint) (y + halfSize));
+ GLboolean round = GL_TRUE;
+ GLint ix, iy;
+ GLuint slot, j;
+
+ /* For points, all interpolants are constant-valued.
+ * However, for point sprites, we'll need to setup texcoords appropriately.
+ * XXX: which coefficients are the texcoords???
+ * We may do point sprites as textured quads...
+ *
+ * KW: We don't know which coefficients are texcoords - ultimately
+ * the choice of what interpolation mode to use for each attribute
+ * should be determined by the fragment program, using
+ * per-attribute declaration statements that include interpolation
+ * mode as a parameter. So either the fragment program will have
+ * to be adjusted for pointsprite vs normal point behaviour, or
+ * otherwise a special interpolation mode will have to be defined
+ * which matches the required behaviour for point sprites. But -
+ * the latter is not a feature of normal hardware, and as such
+ * probably should be ruled out on that basis.
+ */
+ setup->vprovoke = prim->v[0];
+ const_coeff(setup, 0, 2);
+ const_coeff(setup, 0, 3);
+ for (slot = 1; slot < setup->quad.nr_attrs; slot++) {
+ for (j = 0; j < NUM_CHANNELS; j++)
+ const_coeff(setup, slot, j);
+ }
+
+ /* XXX need to clip against scissor bounds too */
+
+ for (iy = iymin; iy <= iymax; iy += 2) {
+ for (ix = ixmin; ix <= ixmax; ix += 2) {
+
+ if (round) {
+ /* rounded points */
+ /* XXX for GL_SMOOTH, need to compute per-fragment coverage too */
+ GLfloat dx, dy;
+
+ setup->quad.mask = 0x0;
+
+ dx = (ix + 0.5) - x;
+ dy = (iy + 0.5) - y;
+ if (dx * dx + dy * dy <= halfSizeSquared)
+ setup->quad.mask |= MASK_BOTTOM_LEFT;
+
+ dx = (ix + 1.5) - x;
+ dy = (iy + 0.5) - y;
+ if (dx * dx + dy * dy <= halfSizeSquared)
+ setup->quad.mask |= MASK_BOTTOM_RIGHT;
+
+ dx = (ix + 0.5) - x;
+ dy = (iy + 1.5) - y;
+ if (dx * dx + dy * dy <= halfSizeSquared)
+ setup->quad.mask |= MASK_TOP_LEFT;
+
+ dx = (ix + 1.5) - x;
+ dy = (iy + 1.5) - y;
+ if (dx * dx + dy * dy <= halfSizeSquared)
+ setup->quad.mask |= MASK_TOP_RIGHT;
+ }
+ else {
+ /* square points */
+ setup->quad.mask = 0xf;
+
+ if (ix + 0.5 < x - halfSize)
+ setup->quad.mask &= (MASK_BOTTOM_RIGHT | MASK_TOP_RIGHT);
+
+ if (ix + 1.5 > x + halfSize)
+ setup->quad.mask &= (MASK_BOTTOM_LEFT | MASK_TOP_LEFT);
+
+ if (iy + 0.5 < y - halfSize)
+ setup->quad.mask &= (MASK_TOP_LEFT | MASK_TOP_RIGHT);
+
+ if (iy + 1.5 > y + halfSize)
+ setup->quad.mask &= (MASK_BOTTOM_LEFT | MASK_BOTTOM_RIGHT);
+ }
+
+ if (setup->quad.mask) {
+ setup->quad.x0 = ix;
+ setup->quad.y0 = iy;
+ quad_shade( setup->stage.softpipe, &setup->quad );
+ }
+ }
+ }
+}
+
+
+
+static void setup_end( struct prim_stage *stage )
+{
+}
+
+
+struct prim_stage *prim_setup( struct softpipe_context *softpipe )
+{
+ struct setup_stage *setup = CALLOC_STRUCT(setup_stage);
+
+ setup->stage.softpipe = softpipe;
+ setup->stage.begin = setup_begin;
+ setup->stage.point = setup_point;
+ setup->stage.line = setup_line;
+ setup->stage.tri = setup_tri;
+ setup->stage.end = setup_end;
+
+ setup->quad.coef = setup->coef;
+
+ return &setup->stage;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-30 14:11:29 +0000