[Mesa-dev] [PATCH] meta/generate_mipmap: Work-around GLES 1.x problem with GL_DRAW_FRAMEBUFFER

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

GL_DRAW_FRAMEBUFFER does not exist in OpenGL ES 1.x, and since
_mesa_meta_begin hasn't been called yet, we have to work-around API
difficulties.  The whole reason that GL_DRAW_FRAMEBUFFER is used instead
of GL_FRAMEBUFFER is that the read framebuffer may be different.  This
is moot in OpenGL ES 1.x.

I have another patch series that would also fix this (by removing the
calls to _mesa_BindFramebuffer and friends), but it's not quite ready
yet... and I think it may be a bit heavy for some stable branches.
Consider this a stop-gap fix.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93215
Cc: "11.0 11.1" <mesa-stable at lists.freedesktop.org>
---
 src/mesa/drivers/common/meta_generate_mipmap.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/mesa/drivers/common/meta_generate_mipmap.c b/src/mesa/drivers/common/meta_generate_mipmap.c
index d38e6b8..2b942d6 100644
--- a/src/mesa/drivers/common/meta_generate_mipmap.c
+++ b/src/mesa/drivers/common/meta_generate_mipmap.c
@@ -62,6 +62,15 @@ fallback_required(struct gl_context *ctx, GLenum target,
    GLuint srcLevel;
    GLenum status;
 
+   /* GL_DRAW_FRAMEBUFFER does not exist in OpenGL ES 1.x, and since
+    * _mesa_meta_begin hasn't been called yet, we have to work-around API
+    * difficulties.  The whole reason that GL_DRAW_FRAMEBUFFER is used instead
+    * of GL_FRAMEBUFFER is that the read framebuffer may be different.  This
+    * is moot in OpenGL ES 1.x.
+    */
+   const GLenum fbo_target = ctx->API == API_OPENGLES
+      ? GL_FRAMEBUFFER : GL_DRAW_FRAMEBUFFER;
+
    /* check for fallbacks */
    if (target == GL_TEXTURE_3D) {
       _mesa_perf_debug(ctx, MESA_DEBUG_SEVERITY_HIGH,
@@ -102,13 +111,13 @@ fallback_required(struct gl_context *ctx, GLenum target,
     */
    if (!mipmap->FBO)
       _mesa_GenFramebuffers(1, &mipmap->FBO);
-   _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, mipmap->FBO);
+   _mesa_BindFramebuffer(fbo_target, mipmap->FBO);
 
-   _mesa_meta_bind_fbo_image(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, baseImage, 0);
+   _mesa_meta_bind_fbo_image(fbo_target, GL_COLOR_ATTACHMENT0, baseImage, 0);
 
-   status = _mesa_CheckFramebufferStatus(GL_DRAW_FRAMEBUFFER);
+   status = _mesa_CheckFramebufferStatus(fbo_target);
 
-   _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, fboSave);
+   _mesa_BindFramebuffer(fbo_target, fboSave);
 
    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
       _mesa_perf_debug(ctx, MESA_DEBUG_SEVERITY_HIGH,
-- 
2.5.0