+ /*
+ * Fragment shader expects pre-multiplied w for LP_INTERP_PERSPECTIVE. A
+ * better stratergy would be to take the primitive in consideration when
+ * generating the fragment shader key, and therefore avoid the per-fragment
+ * perspective divide.
+ */
+
+ float w0 = info->v0[0][3];
+
+ assert(i < 4);
+
+ info->a0[slot][i] = info->v0[slot][i]*w0;
+ info->dadx[slot][i] = 0.0f;
+ info->dady[slot][i] = 0.0f;
+}
+
+
+/**
+ * Setup automatic texcoord coefficients (for sprite rendering).
+ * \param slot the vertex attribute slot to setup
+ * \param i the attribute channel in [0,3]
+ * \param sprite_coord_origin one of PIPE_SPRITE_COORD_x
+ * \param perspective does the shader expects pre-multiplied w, i.e.,
+ * LP_INTERP_PERSPECTIVE is specified in the shader key
+ */
+static void
+texcoord_coef(struct lp_setup_context *setup,
+ const struct point_info *info,
+ unsigned slot,
+ unsigned i,
+ unsigned sprite_coord_origin,
+ boolean perspective)
+{
+ float w0 = info->v0[0][3];
+
+ assert(i < 4);
+
+ if (i == 0) {
+ float dadx = FIXED_ONE / (float)info->dx12;
+ float dady = 0.0f;
+ float x0 = info->v0[0][0] - setup->pixel_offset;
+ float y0 = info->v0[0][1] - setup->pixel_offset;
+
+ info->dadx[slot][0] = dadx;
+ info->dady[slot][0] = dady;
+ info->a0[slot][0] = 0.5 - (dadx * x0 + dady * y0);
+
+ if (perspective) {
+ info->dadx[slot][0] *= w0;
+ info->dady[slot][0] *= w0;
+ info->a0[slot][0] *= w0;
+ }
+ }
+ else if (i == 1) {
+ float dadx = 0.0f;
+ float dady = FIXED_ONE / (float)info->dx12;
+ float x0 = info->v0[0][0] - setup->pixel_offset;
+ float y0 = info->v0[0][1] - setup->pixel_offset;
+
+ if (sprite_coord_origin == PIPE_SPRITE_COORD_LOWER_LEFT) {
+ dady = -dady;
+ }
+
+ info->dadx[slot][1] = dadx;
+ info->dady[slot][1] = dady;
+ info->a0[slot][1] = 0.5 - (dadx * x0 + dady * y0);
+
+ if (perspective) {
+ info->dadx[slot][1] *= w0;
+ info->dady[slot][1] *= w0;
+ info->a0[slot][1] *= w0;
+ }
+ }
+ else if (i == 2) {
+ info->a0[slot][2] = 0.0f;
+ info->dadx[slot][2] = 0.0f;
+ info->dady[slot][2] = 0.0f;
+ }
+ else {
+ info->a0[slot][3] = perspective ? w0 : 1.0f;
+ info->dadx[slot][3] = 0.0f;
+ info->dady[slot][3] = 0.0f;
+ }
+}
+
+
+/**
+ * Special coefficient setup for gl_FragCoord.
+ * X and Y are trivial
+ * Z and W are copied from position_coef which should have already been computed.
+ * We could do a bit less work if we'd examine gl_FragCoord's swizzle mask.
+ */
+static void
+setup_point_fragcoord_coef(struct lp_setup_context *setup,
+ struct point_info *info,
+ unsigned slot,
+ unsigned usage_mask)
+{
+ /*X*/
+ if (usage_mask & TGSI_WRITEMASK_X) {
+ info->a0[slot][0] = 0.0;
+ info->dadx[slot][0] = 1.0;
+ info->dady[slot][0] = 0.0;
+ }
+
+ /*Y*/
+ if (usage_mask & TGSI_WRITEMASK_Y) {
+ info->a0[slot][1] = 0.0;
+ info->dadx[slot][1] = 0.0;
+ info->dady[slot][1] = 1.0;
+ }
+
+ /*Z*/
+ if (usage_mask & TGSI_WRITEMASK_Z) {
+ constant_coef(setup, info, slot, info->v0[0][2], 2);
+ }
+
+ /*W*/
+ if (usage_mask & TGSI_WRITEMASK_W) {
+ constant_coef(setup, info, slot, info->v0[0][3], 3);
+ }
+}
+
+
+/**
+ * Compute the point->coef[] array dadx, dady, a0 values.
+ */
+static void
+setup_point_coefficients( struct lp_setup_context *setup,
+ struct point_info *info)
+{
+ const struct lp_setup_variant_key *key = &setup->setup.variant->key;
+ const struct lp_fragment_shader *shader = setup->fs.current.variant->shader;
+ unsigned fragcoord_usage_mask = TGSI_WRITEMASK_XYZ;
+ unsigned slot;
+
+ /* setup interpolation for all the remaining attributes:
+ */
+ for (slot = 0; slot < key->num_inputs; slot++) {
+ unsigned vert_attr = key->inputs[slot].src_index;
+ unsigned usage_mask = key->inputs[slot].usage_mask;
+ enum lp_interp interp = key->inputs[slot].interp;
+ boolean perspective = !!(interp == LP_INTERP_PERSPECTIVE);
+ unsigned i;
+
+ if (perspective & usage_mask) {
+ fragcoord_usage_mask |= TGSI_WRITEMASK_W;
+ }
+
+ switch (interp) {
+ case LP_INTERP_POSITION:
+ /*
+ * The generated pixel interpolators will pick up the coeffs from
+ * slot 0, so all need to ensure that the usage mask is covers all
+ * usages.
+ */
+ fragcoord_usage_mask |= usage_mask;
+ break;
+
+ case LP_INTERP_LINEAR:
+ /* Sprite tex coords may use linear interpolation someday */
+ /* fall-through */
+ case LP_INTERP_PERSPECTIVE:
+ /* check if the sprite coord flag is set for this attribute.
+ * If so, set it up so it up so x and y vary from 0 to 1.
+ */
+ if (shader->info.base.input_semantic_name[slot] == TGSI_SEMANTIC_GENERIC) {
+ unsigned semantic_index = shader->info.base.input_semantic_index[slot];
+ /* Note that sprite_coord enable is a bitfield of
+ * PIPE_MAX_SHADER_OUTPUTS bits.
+ */
+ if (semantic_index < PIPE_MAX_SHADER_OUTPUTS &&
+ (setup->sprite_coord_enable & (1 << semantic_index))) {
+ for (i = 0; i < NUM_CHANNELS; i++) {
+ if (usage_mask & (1 << i)) {
+ texcoord_coef(setup, info, slot + 1, i,
+ setup->sprite_coord_origin,
+ perspective);
+ }
+ }
+ break;
+ }
+ }
+ /* fall-through */
+ case LP_INTERP_CONSTANT:
+ for (i = 0; i < NUM_CHANNELS; i++) {
+ if (usage_mask & (1 << i)) {
+ if (perspective) {
+ point_persp_coeff(setup, info, slot+1, i);
+ }
+ else {
+ constant_coef(setup, info, slot+1, info->v0[vert_attr][i], i);
+ }
+ }
+ }
+ break;
+
+ case LP_INTERP_FACING:
+ for (i = 0; i < NUM_CHANNELS; i++)
+ if (usage_mask & (1 << i))
+ constant_coef(setup, info, slot+1, 1.0, i);
+ break;
+
+ default:
+ assert(0);
+ break;
+ }
+ }
+
+ /* The internal position input is in slot zero:
+ */
+ setup_point_fragcoord_coef(setup, info, 0,
+ fragcoord_usage_mask);
+}
+
+
+static INLINE int
+subpixel_snap(float a)
+{
+ return util_iround(FIXED_ONE * a);
+}
+
+
+static boolean
+try_setup_point( struct lp_setup_context *setup,
+ const float (*v0)[4] )
+{
+ /* x/y positions in fixed point */
+ const struct lp_setup_variant_key *key = &setup->setup.variant->key;
+ const int sizeAttr = setup->psize;
+ const float size
+ = (setup->point_size_per_vertex && sizeAttr > 0) ? v0[sizeAttr][0]
+ : setup->point_size;
+
+ /* Point size as fixed point integer, remove rounding errors
+ * and gives minimum width for very small points
+ */
+ int fixed_width = MAX2(FIXED_ONE,
+ (subpixel_snap(size) + FIXED_ONE/2 - 1) & ~(FIXED_ONE-1));
+
+ const int x0 = subpixel_snap(v0[0][0] - setup->pixel_offset) - fixed_width/2;
+ const int y0 = subpixel_snap(v0[0][1] - setup->pixel_offset) - fixed_width/2;
+
+ struct lp_scene *scene = setup->scene;
+ struct lp_rast_triangle *point;
+ unsigned bytes;
+ struct u_rect bbox;
+ unsigned nr_planes = 4;
+ struct point_info info;
+
+
+ /* Bounding rectangle (in pixels) */
+ {
+ /* Yes this is necessary to accurately calculate bounding boxes
+ * with the two fill-conventions we support. GL (normally) ends
+ * up needing a bottom-left fill convention, which requires
+ * slightly different rounding.
+ */
+ int adj = (setup->pixel_offset != 0) ? 1 : 0;
+
+ bbox.x0 = (x0 + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
+ bbox.x1 = (x0 + fixed_width + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
+ bbox.y0 = (y0 + (FIXED_ONE-1)) >> FIXED_ORDER;
+ bbox.y1 = (y0 + fixed_width + (FIXED_ONE-1)) >> FIXED_ORDER;
+
+ /* Inclusive coordinates:
+ */
+ bbox.x1--;
+ bbox.y1--;
+ }
+
+ if (!u_rect_test_intersection(&setup->draw_region, &bbox)) {
+ if (0) debug_printf("offscreen\n");
+ LP_COUNT(nr_culled_tris);
+ return TRUE;
+ }
+
+ u_rect_find_intersection(&setup->draw_region, &bbox);
+
+ point = lp_setup_alloc_triangle(scene,
+ key->num_inputs,
+ nr_planes,
+ &bytes);
+ if (!point)
+ return FALSE;
+
+#ifdef DEBUG
+ point->v[0][0] = v0[0][0];
+ point->v[0][1] = v0[0][1];
+#endif
+
+ info.v0 = v0;
+ info.dx01 = 0;
+ info.dx12 = fixed_width;
+ info.dy01 = fixed_width;
+ info.dy12 = 0;
+ info.a0 = GET_A0(&point->inputs);
+ info.dadx = GET_DADX(&point->inputs);
+ info.dady = GET_DADY(&point->inputs);
+
+ /* Setup parameter interpolants:
+ */
+ setup_point_coefficients(setup, &info);
+
+ point->inputs.frontfacing = TRUE;
+ point->inputs.disable = FALSE;
+ point->inputs.opaque = FALSE;
+
+ {
+ struct lp_rast_plane *plane = GET_PLANES(point);
+
+ plane[0].dcdx = -1;
+ plane[0].dcdy = 0;
+ plane[0].c = 1-bbox.x0;
+ plane[0].eo = 1;
+
+ plane[1].dcdx = 1;
+ plane[1].dcdy = 0;
+ plane[1].c = bbox.x1+1;
+ plane[1].eo = 0;
+
+ plane[2].dcdx = 0;
+ plane[2].dcdy = 1;
+ plane[2].c = 1-bbox.y0;
+ plane[2].eo = 1;
+
+ plane[3].dcdx = 0;
+ plane[3].dcdy = -1;
+ plane[3].c = bbox.y1+1;
+ plane[3].eo = 0;
+ }
+
+ return lp_setup_bin_triangle(setup, point, &bbox, nr_planes);
+}
+
+
+static void
+lp_setup_point(struct lp_setup_context *setup,
+ const float (*v0)[4])
+{
+ if (!try_setup_point( setup, v0 ))
+ {
+ if (!lp_setup_flush_and_restart(setup))
+ return;
+
+ if (!try_setup_point( setup, v0 ))
+ return;
+ }