r300g: implement MSAA

This is not as optimized as r600g - the MSAA compression is missing,
so r300g needs a lot of bandwidth (more than r600g to do the same thing).
However, if the bandwidth is not an issue for you, you can enjoy this
unoptimized MSAA support.
The only other missing optimization for MSAA is the fast color clear.

MSAA is enabled on r500 only, because that's the only GPU family I tested.
That said, MSAA should work on r300 and r400 as well (but you must set
RADEON_MSAA=1 to allow it, then turn MSAA on in your app or set GALLIUM_MSAA=n,
n >= 2, n <= 6)
I will enable the support by default on r300-r400 once someone (other than me)
tests those chipsets with piglit.

The supported modes are 2x, 4x, 6x.

The supported MSAA formats are RGBA8, BGRA8, and RGBA16F (r500 only).
Those 3 formats are used for all GL internal formats.

Tested with piglit. (I have ported all MSAA tests to GL2.1)

1 files changed, 158 insertions, 13 deletions

diff --git a/src/gallium/drivers/r300/r300_blit.c b/src/gallium/drivers/r300/r300_blit.c
index 9fff370..4657831 100644
--- a/src/gallium/drivers/r300/r300_blit.c
+++ b/src/gallium/drivers/r300/r300_blit.c
@@ -23,6 +23,7 @@
 #include "r300_context.h"
 #include "r300_emit.h"
 #include "r300_texture.h"
+#include "r300_reg.h"
 
 #include "util/u_format.h"
 #include "util/u_pack_color.h"
@@ -66,6 +67,7 @@ static void r300_blitter_begin(struct r300_context* r300, enum r300_blitter_op o
     util_blitter_save_vertex_shader(r300->blitter, r300->vs_state.state);
     util_blitter_save_viewport(r300->blitter, &r300->viewport);
     util_blitter_save_scissor(r300->blitter, r300->scissor_state.state);
+    util_blitter_save_sample_mask(r300->blitter, *(unsigned*)r300->sample_mask.state);
     util_blitter_save_vertex_buffer_slot(r300->blitter, r300->vertex_buffer);
     util_blitter_save_vertex_elements(r300->blitter, r300->velems);
 
@@ -478,6 +480,11 @@ static void r300_resource_copy_region(struct pipe_context *pipe,
         return;
     }
 
+    /* Can't read MSAA textures. */
+    if (src->nr_samples > 1 || dst->nr_samples > 1) {
+        return;
+    }
+
     /* The code below changes the texture format so that the copy can be done
      * on hardware. E.g. depth-stencil surfaces are copied as RGBA
      * colorbuffers. */
@@ -595,20 +602,141 @@ static void r300_resource_copy_region(struct pipe_context *pipe,
     pipe_sampler_view_reference(&src_view, NULL);
 }
 
+static boolean r300_is_simple_msaa_resolve(const struct pipe_blit_info *info)
+{
+    unsigned dst_width = u_minify(info->dst.resource->width0, info->dst.level);
+    unsigned dst_height = u_minify(info->dst.resource->height0, info->dst.level);
+
+    return info->dst.resource->format == info->src.resource->format &&
+           info->dst.resource->format == info->dst.format &&
+           info->src.resource->format == info->src.format &&
+           !info->scissor_enable &&
+           info->mask == PIPE_MASK_RGBA &&
+           dst_width == info->src.resource->width0 &&
+           dst_height == info->src.resource->height0 &&
+           info->dst.box.x == 0 &&
+           info->dst.box.y == 0 &&
+           info->dst.box.width == dst_width &&
+           info->dst.box.height == dst_height &&
+           info->src.box.x == 0 &&
+           info->src.box.y == 0 &&
+           info->src.box.width == dst_width &&
+           info->src.box.height == dst_height;
+}
+
+static void r300_simple_msaa_resolve(struct pipe_context *pipe,
+                                     struct pipe_resource *dst,
+                                     unsigned dst_level,
+                                     unsigned dst_layer,
+                                     struct pipe_resource *src,
+                                     enum pipe_format format)
+{
+    struct r300_context *r300 = r300_context(pipe);
+    struct r300_surface *srcsurf, *dstsurf;
+    struct pipe_surface surf_tmpl;
+    struct r300_aa_state *aa = (struct r300_aa_state*)r300->aa_state.state;
+
+    memset(&surf_tmpl, 0, sizeof(surf_tmpl));
+    surf_tmpl.format = format;
+    srcsurf = r300_surface(pipe->create_surface(pipe, src, &surf_tmpl));
+
+    surf_tmpl.format = format;
+    surf_tmpl.u.tex.level = dst_level;
+    surf_tmpl.u.tex.first_layer =
+    surf_tmpl.u.tex.last_layer = dst_layer;
+    dstsurf = r300_surface(pipe->create_surface(pipe, dst, &surf_tmpl));
+
+    /* COLORPITCH should contain the tiling info of the resolve buffer.
+     * The tiling of the AA buffer isn't programmable anyway. */
+    srcsurf->pitch &= ~(R300_COLOR_TILE(1) | R300_COLOR_MICROTILE(3));
+    srcsurf->pitch |= dstsurf->pitch & (R300_COLOR_TILE(1) | R300_COLOR_MICROTILE(3));
+
+    /* Enable AA resolve. */
+    aa->dest = dstsurf;
+    r300->aa_state.size = 8;
+    r300_mark_atom_dirty(r300, &r300->aa_state);
+
+    /* Resolve the surface. */
+    r300_blitter_begin(r300, R300_CLEAR_SURFACE);
+    util_blitter_custom_color(r300->blitter, &srcsurf->base, NULL);
+    r300_blitter_end(r300);
+
+    /* Disable AA resolve. */
+    aa->dest = NULL;
+    r300->aa_state.size = 4;
+    r300_mark_atom_dirty(r300, &r300->aa_state);
+
+    pipe_surface_reference((struct pipe_surface**)&srcsurf, NULL);
+    pipe_surface_reference((struct pipe_surface**)&dstsurf, NULL);
+}
+
+static void r300_msaa_resolve(struct pipe_context *pipe,
+                              const struct pipe_blit_info *info)
+{
+    struct r300_context *r300 = r300_context(pipe);
+    struct pipe_screen *screen = pipe->screen;
+    struct pipe_resource *tmp, templ;
+    struct pipe_blit_info blit;
+
+    assert(info->src.level == 0);
+    assert(info->src.box.z == 0);
+    assert(info->src.box.depth == 1);
+    assert(info->dst.box.depth == 1);
+
+    if (r300_is_simple_msaa_resolve(info)) {
+        r300_simple_msaa_resolve(pipe, info->dst.resource, info->dst.level,
+                                 info->dst.box.z, info->src.resource,
+                                 info->src.format);
+        return;
+    }
+
+    /* resolve into a temporary texture, then blit */
+    memset(&templ, 0, sizeof(templ));
+    templ.target = PIPE_TEXTURE_2D;
+    templ.format = info->src.resource->format;
+    templ.width0 = info->src.resource->width0;
+    templ.height0 = info->src.resource->height0;
+    templ.depth0 = 1;
+    templ.array_size = 1;
+    templ.usage = PIPE_USAGE_STATIC;
+
+    tmp = screen->resource_create(screen, &templ);
+
+    /* resolve */
+    r300_simple_msaa_resolve(pipe, tmp, 0, 0, info->src.resource,
+                             info->src.format);
+
+    /* blit */
+    blit = *info;
+    blit.src.resource = tmp;
+    blit.src.box.z = 0;
+
+    r300_blitter_begin(r300, R300_BLIT);
+    util_blitter_blit(r300->blitter, &blit);
+    r300_blitter_end(r300);
+
+    pipe_resource_reference(&tmp, NULL);
+}
+
 static void r300_blit(struct pipe_context *pipe,
-                      const struct pipe_blit_info *blit_info)
+                      const struct pipe_blit_info *blit)
 {
     struct r300_context *r300 = r300_context(pipe);
     struct pipe_framebuffer_state *fb =
         (struct pipe_framebuffer_state*)r300->fb_state.state;
-    struct pipe_blit_info info = *blit_info;
+    struct pipe_blit_info info = *blit;
 
-    /* Decompress ZMASK. */
-    if (r300->zmask_in_use && !r300->locked_zbuffer) {
-        if (fb->zsbuf->texture == info.src.resource ||
-            fb->zsbuf->texture == info.dst.resource) {
-            r300_decompress_zmask(r300);
-        }
+    /* MSAA resolve. */
+    if (info.src.resource->nr_samples > 1 &&
+        info.dst.resource->nr_samples <= 1 &&
+        !util_format_is_depth_or_stencil(info.src.resource->format)) {
+        r300_msaa_resolve(pipe, &info);
+        return;
+    }
+
+    /* Can't read MSAA textures. */
+    if (info.src.resource->nr_samples > 1) {
+        return;
     }
 
     /* Blit a combined depth-stencil resource as color.
@@ -616,12 +744,29 @@ static void r300_blit(struct pipe_context *pipe,
     if ((info.mask & PIPE_MASK_S) &&
         info.src.format == PIPE_FORMAT_S8_UINT_Z24_UNORM &&
         info.dst.format == PIPE_FORMAT_S8_UINT_Z24_UNORM) {
-        info.src.format = PIPE_FORMAT_B8G8R8A8_UNORM;
-        info.dst.format = PIPE_FORMAT_B8G8R8A8_UNORM;
-        if (info.mask & PIPE_MASK_Z) {
-            info.mask = PIPE_MASK_RGBA; /* depth+stencil */
+        if (info.dst.resource->nr_samples > 1) {
+            /* Cannot do that with MSAA buffers. */
+            info.mask &= ~PIPE_MASK_S;
+            if (!(info.mask & PIPE_MASK_Z)) {
+                return;
+            }
         } else {
-            info.mask = PIPE_MASK_B; /* stencil only */
+            /* Single-sample buffer. */
+            info.src.format = PIPE_FORMAT_B8G8R8A8_UNORM;
+            info.dst.format = PIPE_FORMAT_B8G8R8A8_UNORM;
+            if (info.mask & PIPE_MASK_Z) {
+                info.mask = PIPE_MASK_RGBA; /* depth+stencil */
+            } else {
+                info.mask = PIPE_MASK_B; /* stencil only */
+            }
+        }
+    }
+
+    /* Decompress ZMASK. */
+    if (r300->zmask_in_use && !r300->locked_zbuffer) {
+        if (fb->zsbuf->texture == info.src.resource ||
+            fb->zsbuf->texture == info.dst.resource) {
+            r300_decompress_zmask(r300);
         }
     }