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Diffstat (limited to 'src/gallium/drivers/softpipe/sp_quad_stipple.c')
-rw-r--r--src/gallium/drivers/softpipe/sp_quad_stipple.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/src/gallium/drivers/softpipe/sp_quad_stipple.c b/src/gallium/drivers/softpipe/sp_quad_stipple.c
new file mode 100644
index 0000000000..ccf37f6be5
--- /dev/null
+++ b/src/gallium/drivers/softpipe/sp_quad_stipple.c
@@ -0,0 +1,94 @@
+
+/**
+ * quad polygon stipple stage
+ */
+
+#include "sp_context.h"
+#include "sp_headers.h"
+#include "sp_quad.h"
+#include "pipe/p_defines.h"
+#include "util/u_memory.h"
+
+
+/**
+ * Apply polygon stipple to quads produced by triangle rasterization
+ */
+static void
+stipple_quad(struct quad_stage *qs, struct quad_header *quad)
+{
+ static const uint bit31 = 1 << 31;
+ static const uint bit30 = 1 << 30;
+
+ if (quad->input.prim == PRIM_TRI) {
+ struct softpipe_context *softpipe = qs->softpipe;
+ /* need to invert Y to index into OpenGL's stipple pattern */
+ int y0, y1;
+ uint stipple0, stipple1;
+ if (softpipe->rasterizer->origin_lower_left) {
+ y0 = softpipe->framebuffer.height - 1 - quad->input.y0;
+ y1 = y0 - 1;
+ }
+ else {
+ y0 = quad->input.y0;
+ y1 = y0 + 1;
+ }
+ stipple0 = softpipe->poly_stipple.stipple[y0 % 32];
+ stipple1 = softpipe->poly_stipple.stipple[y1 % 32];
+
+#if 1
+ {
+ const int col0 = quad->input.x0 % 32;
+ if ((stipple0 & (bit31 >> col0)) == 0)
+ quad->inout.mask &= ~MASK_TOP_LEFT;
+
+ if ((stipple0 & (bit30 >> col0)) == 0)
+ quad->inout.mask &= ~MASK_TOP_RIGHT;
+
+ if ((stipple1 & (bit31 >> col0)) == 0)
+ quad->inout.mask &= ~MASK_BOTTOM_LEFT;
+
+ if ((stipple1 & (bit30 >> col0)) == 0)
+ quad->inout.mask &= ~MASK_BOTTOM_RIGHT;
+ }
+#else
+ /* We'd like to use this code, but we'd need to redefine
+ * MASK_TOP_LEFT to be (1 << 1) and MASK_TOP_RIGHT to be (1 << 0),
+ * and similarly for the BOTTOM bits. But that may have undesirable
+ * side effects elsewhere.
+ */
+ const int col0 = 30 - (quad->input.x0 % 32);
+ quad->inout.mask &= (((stipple0 >> col0) & 0x3) |
+ (((stipple1 >> col0) & 0x3) << 2));
+#endif
+ if (!quad->inout.mask)
+ return;
+ }
+
+ qs->next->run(qs->next, quad);
+}
+
+
+static void stipple_begin(struct quad_stage *qs)
+{
+ qs->next->begin(qs->next);
+}
+
+
+static void stipple_destroy(struct quad_stage *qs)
+{
+ FREE( qs );
+}
+
+
+struct quad_stage *
+sp_quad_polygon_stipple_stage( struct softpipe_context *softpipe )
+{
+ struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
+
+ stage->softpipe = softpipe;
+ stage->begin = stipple_begin;
+ stage->run = stipple_quad;
+ stage->destroy = stipple_destroy;
+
+ return stage;
+}