r600g: add get_sample_position support (v3)

v2: I rewrote this to use the sample positions properly.
v3: rewrite properly to use bitfield to cast back to signed ints

Signed-off-by: Dave Airlie <[email protected]>

1 files changed, 59 insertions, 16 deletions

diff --git a/src/gallium/drivers/r600/r600_state.c b/src/gallium/drivers/r600/r600_state.c
index a7e69238bbe..b30e053ce52 100644
--- a/src/gallium/drivers/r600/r600_state.c
+++ b/src/gallium/drivers/r600/r600_state.c
@@ -1686,24 +1686,65 @@ static void r600_set_framebuffer_state(struct pipe_context *ctx,
 	(((s2x) & 0xf) << 16) | (((s2y) & 0xf) << 20) |	   \
 	 (((s3x) & 0xf) << 24) | (((s3y) & 0xf) << 28))
 
+
+static uint32_t sample_locs_2x[] = {
+	FILL_SREG(-4, 4, 4, -4, -4, 4, 4, -4),
+	FILL_SREG(-4, 4, 4, -4, -4, 4, 4, -4),
+};
+static unsigned max_dist_2x = 4;
+
+static uint32_t sample_locs_4x[] = {
+	FILL_SREG(-2, -2, 2, 2, -6, 6, 6, -6),
+	FILL_SREG(-2, -2, 2, 2, -6, 6, 6, -6),
+};
+static unsigned max_dist_4x = 6;
+static uint32_t sample_locs_8x[] = {
+	FILL_SREG(-1,  1,  1,  5,  3, -5,  5,  3),
+	FILL_SREG(-7, -1, -3, -7,  7, -3, -5,  7),
+};
+static unsigned max_dist_8x = 7;
+
+static void r600_get_sample_position(struct pipe_context *ctx,
+				     unsigned sample_count,
+				     unsigned sample_index,
+				     float *out_value)
+{
+	int offset, index;
+	struct {
+		int idx:4;
+	} val;
+	switch (sample_count) {
+	case 1:
+	default:
+		out_value[0] = out_value[1] = 0.5;
+		break;
+	case 2:
+		offset = 4 * (sample_index * 2);
+		val.idx = (sample_locs_2x[0] >> offset) & 0xf;
+		out_value[0] = (float)(val.idx + 8) / 16.0f;
+		val.idx = (sample_locs_2x[0] >> (offset + 4)) & 0xf;
+		out_value[1] = (float)(val.idx + 8) / 16.0f;
+		break;
+	case 4:
+		offset = 4 * (sample_index * 2);
+		val.idx = (sample_locs_4x[0] >> offset) & 0xf;
+		out_value[0] = (float)(val.idx + 8) / 16.0f;
+		val.idx = (sample_locs_4x[0] >> (offset + 4)) & 0xf;
+		out_value[1] = (float)(val.idx + 8) / 16.0f;
+		break;
+	case 8:
+		offset = 4 * (sample_index % 4 * 2);
+		index = (sample_index / 4);
+		val.idx = (sample_locs_8x[index] >> offset) & 0xf;
+		out_value[0] = (float)(val.idx + 8) / 16.0f;
+		val.idx = (sample_locs_8x[index] >> (offset + 4)) & 0xf;
+		out_value[1] = (float)(val.idx + 8) / 16.0f;
+		break;
+	}
+}
+
 static void r600_emit_msaa_state(struct r600_context *rctx, int nr_samples)
 {
-	static uint32_t sample_locs_2x[] = {
-		FILL_SREG(-4, 4, 4, -4, -4, 4, 4, -4),
-		FILL_SREG(-4, 4, 4, -4, -4, 4, 4, -4),
-	};
-	static unsigned max_dist_2x = 4;
-	static uint32_t sample_locs_4x[] = {
-		FILL_SREG(-2, -2, 2, 2, -6, 6, 6, -6),
-		FILL_SREG(-2, -2, 2, 2, -6, 6, 6, -6),
-	};
-	static unsigned max_dist_4x = 6;
-	static uint32_t sample_locs_8x[] = {
-		FILL_SREG(-1,  1,  1,  5,  3, -5,  5,  3),
-		FILL_SREG(-7, -1, -3, -7,  7, -3, -5,  7),
-	};
-	static unsigned max_dist_8x = 7;
-
 	struct radeon_winsys_cs *cs = rctx->rings.gfx.cs;
 	unsigned max_dist = 0;
 
@@ -3211,5 +3252,7 @@ void r600_init_state_functions(struct r600_context *rctx)
 	rctx->context.set_framebuffer_state = r600_set_framebuffer_state;
 	rctx->context.set_polygon_stipple = r600_set_polygon_stipple;
 	rctx->context.set_scissor_state = r600_set_scissor_state;
+
+	rctx->context.get_sample_position = r600_get_sample_position;
 }
 /* this function must be last */