swrast: MapRenderbuffer in separate depth/stencil readpixels fastpath
authorEric Anholt <eric@anholt.net>
Wed, 12 Oct 2011 19:40:18 +0000 (12:40 -0700)
committerEric Anholt <eric@anholt.net>
Fri, 4 Nov 2011 06:29:52 +0000 (23:29 -0700)
This introduces two new span helper functions we'll want to use in
several places as we move to MapRenderbuffer, which pull out integer
depth and stencil values from a renderbuffer mapping based on the
renderbuffer format.

v2: Use format_unpack helper for stencil read.
v3: Clean up comment after conversion to format_unpack.

Reviewed-by: Brian Paul <brianp@vmware.com>
src/mesa/swrast/s_depth.h
src/mesa/swrast/s_readpix.c

index 44820ac..8d5cdfa 100644 (file)
@@ -53,7 +53,6 @@ extern void
 _swrast_read_depth_span_uint( struct gl_context *ctx, struct gl_renderbuffer *rb,
                               GLint n, GLint x, GLint y, GLuint depth[] );
 
-
 extern void
 _swrast_clear_depth_buffer( struct gl_context *ctx, struct gl_renderbuffer *rb );
 
index f6c3674..6de310b 100644 (file)
@@ -366,14 +366,14 @@ read_rgba_pixels( struct gl_context *ctx,
 }
 
 /**
- * For a packed depth/stencil buffer being read as depth/stencil, memcpy the
+ * For a packed depth/stencil buffer being read as depth/stencil, just memcpy the
  * data (possibly swapping 8/24 vs 24/8 as we go).
  */
 static GLboolean
 fast_read_depth_stencil_pixels(struct gl_context *ctx,
                               GLint x, GLint y,
                               GLsizei width, GLsizei height,
-                              GLenum type, GLvoid *dst, int dstStride)
+                              GLvoid *dst, int dstStride)
 {
    struct gl_framebuffer *fb = ctx->ReadBuffer;
    struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
@@ -384,9 +384,6 @@ fast_read_depth_stencil_pixels(struct gl_context *ctx,
    if (rb != stencilRb)
       return GL_FALSE;
 
-   if (type != GL_UNSIGNED_INT_24_8)
-      return GL_FALSE;
-
    if (rb->Format != MESA_FORMAT_Z24_S8 &&
        rb->Format != MESA_FORMAT_S8_Z24)
       return GL_FALSE;
@@ -408,6 +405,54 @@ fast_read_depth_stencil_pixels(struct gl_context *ctx,
 
 
 /**
+ * For non-float-depth and stencil buffers being read as 24/8 depth/stencil,
+ * copy the integer data directly instead of converting depth to float and
+ * re-packing.
+ */
+static GLboolean
+fast_read_depth_stencil_pixels_separate(struct gl_context *ctx,
+                                       GLint x, GLint y,
+                                       GLsizei width, GLsizei height,
+                                       uint32_t *dst, int dstStride)
+{
+   struct gl_framebuffer *fb = ctx->ReadBuffer;
+   struct gl_renderbuffer *depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
+   struct gl_renderbuffer *stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
+   GLubyte *depthMap, *stencilMap;
+   int depthStride, stencilStride, i, j;
+
+   if (_mesa_get_format_datatype(depthRb->Format) != GL_UNSIGNED_INT)
+      return GL_FALSE;
+
+   ctx->Driver.MapRenderbuffer(ctx, depthRb, x, y, width, height,
+                              GL_MAP_READ_BIT, &depthMap, &depthStride);
+   ctx->Driver.MapRenderbuffer(ctx, stencilRb, x, y, width, height,
+                              GL_MAP_READ_BIT, &stencilMap, &stencilStride);
+
+   for (j = 0; j < height; j++) {
+      GLstencil stencilVals[MAX_WIDTH];
+
+      _mesa_unpack_uint_z_row(depthRb->Format, width, depthMap, dst);
+      _mesa_unpack_ubyte_stencil_row(stencilRb->Format, width,
+                                    stencilMap, stencilVals);
+
+      for (i = 0; i < width; i++) {
+        dst[i] = (dst[i] & 0xffffff00) | stencilVals[i];
+      }
+
+      depthMap += depthStride;
+      stencilMap += stencilStride;
+      dst += dstStride / 4;
+   }
+
+   ctx->Driver.UnmapRenderbuffer(ctx, depthRb);
+   ctx->Driver.UnmapRenderbuffer(ctx, stencilRb);
+
+   return GL_TRUE;
+}
+
+
+/**
  * Read combined depth/stencil values.
  * We'll have already done error checking to be sure the expected
  * depth and stencil buffers really exist.
@@ -440,10 +485,16 @@ read_depth_stencil_pixels(struct gl_context *ctx,
    dstStride = _mesa_image_row_stride(packing, width,
                                      GL_DEPTH_STENCIL_EXT, type);
 
-   if (!scaleOrBias && !stencilTransfer && !packing->SwapBytes) {
-      if (fast_read_depth_stencil_pixels(ctx, x, y, width, height, type,
+   /* Fast 24/8 reads. */
+   if (type == GL_UNSIGNED_INT_24_8 &&
+       !scaleOrBias && !stencilTransfer && !packing->SwapBytes) {
+      if (fast_read_depth_stencil_pixels(ctx, x, y, width, height,
                                         dst, dstStride))
         return;
+
+      if (fast_read_depth_stencil_pixels_separate(ctx, x, y, width, height,
+                                                 (uint32_t *)dst, dstStride))
+        return;
    }
 
       /* Reading GL_DEPTH_STENCIL pixels from separate depth/stencil buffers,
@@ -459,19 +510,7 @@ read_depth_stencil_pixels(struct gl_context *ctx,
          _swrast_read_stencil_span(ctx, stencilRb, width,
                                    x, y + i, stencilVals);
 
-         if (!scaleOrBias && !stencilTransfer
-             && ctx->ReadBuffer->Visual.depthBits == 24) {
-            /* ideal case */
-            GLuint zVals[MAX_WIDTH]; /* 24-bit values! */
-            GLint j;
-            ASSERT(depthRb->DataType == GL_UNSIGNED_INT);
-            /* note, we've already been clipped */
-            depthRb->GetRow(ctx, depthRb, width, x, y + i, zVals);
-            for (j = 0; j < width; j++) {
-               depthStencilDst[j] = (zVals[j] << 8) | (stencilVals[j] & 0xff);
-            }
-         }
-         else {
+        {
             /* general case */
             GLfloat depthVals[MAX_WIDTH];
             _swrast_read_depth_span_float(ctx, depthRb, width, x, y + i,