/* Authors: Keith Whitwell <keith@tungstengraphics.com>
*/
-#include "pipe/p_util.h"
+/**
+ * Notes on wide points and sprite mode:
+ *
+ * In wide point/sprite mode we effectively need to convert each incoming
+ * vertex into four outgoing vertices specifying the corners of a quad.
+ * Since we don't (yet) have geometry shaders, we have to handle this here
+ * in the draw module.
+ *
+ * For sprites, it also means that this is where we have to handle texcoords
+ * for the vertices of the quad. OpenGL's GL_COORD_REPLACE state specifies
+ * if/how enabled texcoords are automatically generated for sprites. We pass
+ * that info through gallium in the pipe_rasterizer_state::sprite_coord_mode
+ * array.
+ *
+ * Additionally, GLSL's gl_PointCoord fragment attribute has to be handled
+ * here as well. This is basically an additional texture/generic attribute
+ * that varies .x from 0 to 1 horizontally across the point and varies .y
+ * vertically from 0 to 1 down the sprite.
+ *
+ * With geometry shaders, the state tracker could create a GS to do
+ * most/all of this.
+ */
+
+
+#include "util/u_math.h"
+#include "util/u_memory.h"
#include "pipe/p_defines.h"
#include "pipe/p_shader_tokens.h"
#include "draw_vs.h"
uint num_texcoords;
int psize_slot;
+
+ int point_coord_fs_input; /**< input for pointcoord */
};
}
-
-
/**
* Set the vertex texcoords for sprite mode.
* Coords may be left untouched or set to a right-side-up or upside-down
v->data[j][3] = tc[3];
}
}
+
+ if (wide->point_coord_fs_input >= 0) {
+ /* put gl_PointCoord into the extra vertex slot */
+ uint slot = wide->stage.draw->extra_vp_outputs.slot;
+ v->data[slot][0] = tc[0];
+ v->data[slot][1] = tc[1];
+ v->data[slot][2] = 0.0F;
+ v->data[slot][3] = 1.0F;
+ }
}
struct prim_header *header )
{
const struct widepoint_stage *wide = widepoint_stage(stage);
+ const unsigned pos = stage->draw->vs.position_output;
const boolean sprite = (boolean) stage->draw->rasterizer->point_sprite;
float half_size;
float left_adj, right_adj, bot_adj, top_adj;
struct vertex_header *v2 = dup_vert(stage, header->v[0], 2);
struct vertex_header *v3 = dup_vert(stage, header->v[0], 3);
- float *pos0 = v0->data[0];
- float *pos1 = v1->data[0];
- float *pos2 = v2->data[0];
- float *pos3 = v3->data[0];
+ float *pos0 = v0->data[pos];
+ float *pos1 = v1->data[pos];
+ float *pos2 = v2->data[pos];
+ float *pos3 = v3->data[pos];
/* point size is either per-vertex or fixed size */
if (wide->psize_slot >= 0) {
}
+static int
+find_pntc_input_attrib(struct draw_context *draw)
+{
+ /* Scan the fragment program's input decls to find the pointcoord
+ * attribute. The xy components will store the point coord.
+ */
+ return 0; /* XXX fix this */
+}
+
+
static void widepoint_first_point( struct draw_stage *stage,
struct prim_header *header )
{
}
}
wide->num_texcoords = j;
+
+ /* find fragment shader PointCoord input */
+ wide->point_coord_fs_input = find_pntc_input_attrib(draw);
+
+ /* setup extra vp output (point coord implemented as a texcoord) */
+ draw->extra_vp_outputs.semantic_name = TGSI_SEMANTIC_GENERIC;
+ draw->extra_vp_outputs.semantic_index = 0;
+ draw->extra_vp_outputs.slot = draw->vs.num_vs_outputs;
+ }
+ else {
+ wide->point_coord_fs_input = -1;
+ draw->extra_vp_outputs.slot = 0;
}
wide->psize_slot = -1;
{
stage->point = widepoint_first_point;
stage->next->flush( stage->next, flags );
+ stage->draw->extra_vp_outputs.slot = 0;
}
goto fail;
wide->stage.draw = draw;
+ wide->stage.name = "wide-point";
wide->stage.next = NULL;
wide->stage.point = widepoint_first_point;
wide->stage.line = draw_pipe_passthrough_line;