On 03/14/2013 12:45 PM, Marek Olšák wrote:
I'll need the _mesa_readpixels_needs_slow_path function for the blit-based
version, but it's also useful to have this memcpy-based path in one place
and not scattered across several functions.
---
src/mesa/main/readpix.c | 194 ++++++++++++++++++++++++++++++++++++++---------
src/mesa/main/readpix.h | 4 +
2 files changed, 164 insertions(+), 34 deletions(-)
diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index e6d0ecd..790cf2a 100644
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -108,11 +108,145 @@ get_readpixels_transfer_ops(struct gl_context *ctx,
gl_format texFormat,
/**
- * Tries to implement glReadPixels() of GL_DEPTH_COMPONENT using memcpy of the
- * mapping.
+ * Return true if memcpy cannot be used for ReadPixels.
+ *
+ * If uses_blit is true, the function returns true if a simple 3D engine blit
+ * cannot be used for ReadPixels packing.
+ *
+ * NOTE: This doesn't take swizzling and format conversions between
+ * the readbuffer and the pixel pack buffer into account.
*/
+GLboolean
+_mesa_readpixels_needs_slow_path(struct gl_context *ctx, GLenum format,
const *ctx?
+ GLenum type, GLboolean uses_blit)
+{
+ struct gl_renderbuffer *rb =
+ _mesa_get_read_renderbuffer_for_format(ctx, format);
+ GLenum srcType;
+
+ ASSERT(rb);
+
+ /* There are different rules depending on the base format. */
+ switch (format) {
+ case GL_DEPTH_STENCIL:
+ return !_mesa_has_depthstencil_combined(ctx->ReadBuffer) ||
+ ctx->Pixel.DepthScale != 1.0f || ctx->Pixel.DepthBias != 0.0f ||
+ ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset ||
+ ctx->Pixel.MapStencilFlag;
+
+ case GL_DEPTH_COMPONENT:
+ return ctx->Pixel.DepthScale != 1.0f || ctx->Pixel.DepthBias != 0.0f;
+
+ case GL_STENCIL_INDEX:
+ return ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset ||
+ ctx->Pixel.MapStencilFlag;
+
+ default:
+ /* Color formats. */
+ if (need_rgb_to_luminance_conversion(rb->Format, format)) {
+ return GL_TRUE;
+ }
+
+ /* Conversion between signed and unsigned integers needs masking
+ * (it isn't just memcpy). */
+ srcType = _mesa_get_format_datatype(rb->Format);
+
+ if ((srcType == GL_INT&&
+ (type == GL_UNSIGNED_INT ||
+ type == GL_UNSIGNED_SHORT ||
+ type == GL_UNSIGNED_BYTE)) ||
+ (srcType == GL_UNSIGNED_INT&&
+ (type == GL_INT ||
+ type == GL_SHORT ||
+ type == GL_BYTE))) {
+ return GL_TRUE;
+ }
+
+ /* And finally, see if there are any transfer ops. */
+ return get_readpixels_transfer_ops(ctx, rb->Format, format, type,
+ uses_blit) != 0;
+ }
+ return GL_FALSE;
+}
+
+
+static GLboolean
+readpixels_can_use_memcpy(struct gl_context *ctx, GLenum format, GLenum type,
const *ctx?
[...]
Reviewed-by: Brian Paul <bri...@vmware.com>
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
