Work around a Mesa bug wrt. mipmap generation.

diff --git a/effect_chain.cpp b/effect_chain.cpp
index 270eae6c4ce9bd7933c46f3f3ffae1ce4e4ac27b..462633c2916526663bebe217af5b4853b4da09bf 100644 (file)
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@ -303,6 +303,11 @@ void EffectChain::render_to_screen(unsigned char *src)
        check_error();
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        check_error();
+
+       // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here.
+       glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, phases[0].input_needs_mipmaps ? GL_TRUE : GL_FALSE);
+       check_error();
+
        glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
        check_error();
 
@@ -336,8 +341,11 @@ void EffectChain::render_to_screen(unsigned char *src)
                        check_error();
                }
                if (phases[phase].input_needs_mipmaps) {
-                       glGenerateMipmap(GL_TEXTURE_2D);
-                       check_error();
+                       if (phase != 0) {
+                               // For phase 0, it's done further up.
+                               glGenerateMipmap(GL_TEXTURE_2D);
+                               check_error();
+                       }
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
                        check_error();
                } else {