[Mesa-dev] [PATCH] mesa: fix errors when reading depth with glReadPixels

[Tapani Pälli]

OpenGL ES 3.0 spec 3.7.2 "Transfer of Pixel Rectangles" specifies
DEPTH_COMPONENT, UNSIGNED_INT as a valid couple, validation for
internal format is checked by is_float_depth().

Fix regression caused by 81d2fd91a90e5b2fd9fd74792a7a7c329f0e4d29 in:
   ES3-CTS.gtf.GL3Tests.packed_pixels.packed_pixels

Test uses GL_DEPTH_COMPONENT, UNSIGNED_INT only when GL_NV_read_depth
extension is present.

v2: change check in _mesa_error_check_format_and_type to be explicit
    for ES 2.0+, desktop OpenGL does not allow this behaviour + uses
    this function for both glReadPixels and glDrawPixels validation.
    (No Piglit regressions seen with v2.)

Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92009
Cc: "10.7 11.0" <mesa-stable at lists.freedesktop.org>
---
 src/mesa/main/glformats.c | 7 ++++++-
 src/mesa/main/readpix.c   | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/mesa/main/glformats.c b/src/mesa/main/glformats.c
index c1d3c7d..eb4a02a 100644
--- a/src/mesa/main/glformats.c
+++ b/src/mesa/main/glformats.c
@@ -494,7 +494,8 @@ _mesa_bytes_per_pixel(GLenum format, GLenum type)
       else
          return -1;
    case GL_UNSIGNED_INT_24_8_EXT:
-      if (format == GL_DEPTH_STENCIL_EXT)
+      if (format == GL_DEPTH_COMPONENT ||
+          format == GL_DEPTH_STENCIL_EXT)
          return sizeof(GLuint);
       else
          return -1;
@@ -1789,6 +1790,10 @@ _mesa_error_check_format_and_type(const struct gl_context *ctx,
       return GL_INVALID_OPERATION;
 
    case GL_UNSIGNED_INT_24_8:
+      /* Depth buffer OK to read in OpenGL ES (NV_read_depth). */
+      if (ctx->API == API_OPENGLES2 && format == GL_DEPTH_COMPONENT)
+         return GL_NO_ERROR;
+
       if (format != GL_DEPTH_STENCIL) {
          return GL_INVALID_OPERATION;
       }
diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index 76ef8ee..81bb912 100644
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -963,6 +963,7 @@ read_pixels_es3_error_check(GLenum format, GLenum type,
             return GL_NO_ERROR;
          break;
       case GL_UNSIGNED_SHORT:
+      case GL_UNSIGNED_INT:
       case GL_UNSIGNED_INT_24_8:
          if (!is_float_depth)
             return GL_NO_ERROR;
-- 
2.4.3