[Mesa-dev] [PATCH] GlBlitFramebuffer Specification Fix

[Max Qian]

The specification says that if the depth AND stencil formats
do not match, not or. This fixes bug #97921.
---
 src/mesa/main/blit.c | 46 +++++++++++++++++++---------------------------
 1 file changed, 19 insertions(+), 27 deletions(-)

diff --git a/src/mesa/main/blit.c b/src/mesa/main/blit.c
index e739130..62afeb4 100644
--- a/src/mesa/main/blit.c
+++ b/src/mesa/main/blit.c
@@ -334,7 +334,7 @@ _mesa_blit_framebuffer(struct gl_context *ctx,
          mask &= ~GL_STENCIL_BUFFER_BIT;
       }
       else {
-         int read_z_bits, draw_z_bits;
+         int read_z_bits, draw_z_bits, read_s_bit, draw_s_bit;
 
          if (_mesa_is_gles3(ctx) && (drawRb == readRb)) {
             _mesa_error(ctx, GL_INVALID_OPERATION,
@@ -343,28 +343,24 @@ _mesa_blit_framebuffer(struct gl_context *ctx,
             return;
          }
 
-         if (_mesa_get_format_bits(readRb->Format, GL_STENCIL_BITS) !=
-             _mesa_get_format_bits(drawRb->Format, GL_STENCIL_BITS)) {
-            /* There is no need to check the stencil datatype here, because
-             * there is only one: GL_UNSIGNED_INT.
-             */
-            _mesa_error(ctx, GL_INVALID_OPERATION,
-                        "%s(stencil attachment format mismatch)", func);
-            return;
-         }
-
          read_z_bits = _mesa_get_format_bits(readRb->Format, GL_DEPTH_BITS);
          draw_z_bits = _mesa_get_format_bits(drawRb->Format, GL_DEPTH_BITS);
+         read_s_bit = _mesa_get_format_bits(readRb->Format, GL_STENCIL_BITS);
+         draw_s_bit = _mesa_get_format_bits(drawRb->Format, GL_STENCIL_BITS);
 
          /* If both buffers also have depth data, the depth formats must match
           * as well.  If one doesn't have depth, it's not blitted, so we should
           * ignore the depth format check.
           */
-         if (read_z_bits > 0 && draw_z_bits > 0 &&
-             (read_z_bits != draw_z_bits ||
-              _mesa_get_format_datatype(readRb->Format) !=
-              _mesa_get_format_datatype(drawRb->Format))) {
+         if ((read_s_bit != draw_s_bit) &&
+              (read_z_bits > 0 && draw_z_bits > 0 &&
+              (read_z_bits != draw_z_bits ||
+               _mesa_get_format_datatype(readRb->Format) !=
+               _mesa_get_format_datatype(drawRb->Format)))) {
 
+            /* There is no need to check the stencil datatype here, because
+             * there is only one: GL_UNSIGNED_INT.
+             */
             _mesa_error(ctx, GL_INVALID_OPERATION,
                         "%s(stencil attachment depth format mismatch)", func);
             return;
@@ -388,7 +384,7 @@ _mesa_blit_framebuffer(struct gl_context *ctx,
          mask &= ~GL_DEPTH_BUFFER_BIT;
       }
       else {
-         int read_s_bit, draw_s_bit;
+         int read_z_bits, draw_z_bits, read_s_bit, draw_s_bit;
 
          if (_mesa_is_gles3(ctx) && (drawRb == readRb)) {
             _mesa_error(ctx, GL_INVALID_OPERATION,
@@ -397,15 +393,8 @@ _mesa_blit_framebuffer(struct gl_context *ctx,
             return;
          }
 
-         if ((_mesa_get_format_bits(readRb->Format, GL_DEPTH_BITS) !=
-              _mesa_get_format_bits(drawRb->Format, GL_DEPTH_BITS)) ||
-             (_mesa_get_format_datatype(readRb->Format) !=
-              _mesa_get_format_datatype(drawRb->Format))) {
-            _mesa_error(ctx, GL_INVALID_OPERATION,
-                        "%s(depth attachment format mismatch)", func);
-            return;
-         }
-
+         read_z_bits = _mesa_get_format_bits(readRb->Format, GL_DEPTH_BITS);
+         draw_z_bits = _mesa_get_format_bits(drawRb->Format, GL_DEPTH_BITS);
          read_s_bit = _mesa_get_format_bits(readRb->Format, GL_STENCIL_BITS);
          draw_s_bit = _mesa_get_format_bits(drawRb->Format, GL_STENCIL_BITS);
 
@@ -413,9 +402,12 @@ _mesa_blit_framebuffer(struct gl_context *ctx,
           * match as well.  If one doesn't have stencil, it's not blitted, so
           * we should ignore the stencil format check.
           */
-         if (read_s_bit > 0 && draw_s_bit > 0 && read_s_bit != draw_s_bit) {
+         if ((read_s_bit > 0 && draw_s_bit > 0 && read_s_bit != draw_s_bit) &&
+             (read_z_bits != draw_z_bits ||
+              (_mesa_get_format_datatype(readRb->Format) !=
+               _mesa_get_format_datatype(drawRb->Format)))) {
             _mesa_error(ctx, GL_INVALID_OPERATION,
-                        "%s(depth attachment stencil bits mismatch)", func);
+                        "%s(depth attachment stencil bits and format mismatch)", func);
             return;
          }
       }
-- 
2.10.0