Implement NV_path_rendering on OpenGL ES
Implement support for NV_path_rendering on OpenGL ES. Use
glProgramPathFragmentInputGenNV function call instead of glPathTexGenNV to
communicate transforms to fragment shader.
The intention is that the NVPR paths will be drawn with the same shader program
as non-NVPR geometry. For NVPR calls, the GPU will skip the vertex shader and
just run the fragment shader.
After program is linked, query the locations of the fragment shader inputs with
glGetResourceLocation. The location will be used to set the transforms with
glProgramPathFragmentInputGenNV.
The functions and their workings are documented in:
glProgramPathFragmentInputGenNV
https://www.opengl.org/registry/specs/NV/path_rendering.txt
(note: addition as of API version 1.3)
glGetResourceLocation
https://www.opengl.org/registry/specs/ARB/program_interface_query.txt
http://www.opengl.org/registry/doc/glspec44.core.pdf
(function is in core Open GL 4.4)
Note: glProgramPathFragmentInputGenNV could be used also for OpenGL. However,
using seems to trigger a bug in the driver. Disable this feature on OpenGL at
least until the driver is fixed and released. The bug manifests in shadertext
test, where the lower-left text pair is missing. Valgrind catches a bad read
for the test and causes the context to OOM reproducibly.
R=bsalomon@google.com, cdalton@nvidia.com, joshualitt@google.com, joshualitt@chromium.org
Author: kkinnunen@nvidia.com
Review URL: https://codereview.chromium.org/367643004
diff --git a/src/gpu/gl/GrGLDefines.h b/src/gpu/gl/GrGLDefines.h
index 06dd99d..048ad54 100644
--- a/src/gpu/gl/GrGLDefines.h
+++ b/src/gpu/gl/GrGLDefines.h
@@ -900,8 +900,13 @@
// shader stage of <program> (if a fragment stage exists).
#define GR_GL_FRAGMENT_INPUT 0x936D
+// NV_path_rendering extension to EXT_direct_state_access:
+// [the matrix functions] must support the PATH_PROJECTION_NV and
+// PATH_MODELVIEW_NV tokens for matrixMode.
+#define GR_GL_PATH_PROJECTION 0x1701
+#define GR_GL_PATH_MODELVIEW 0x1700
+
/* ARM specific define for MSAA support on framebuffer fetch */
#define GR_GL_FETCH_PER_SAMPLE_ARM 0x8F65
-
#endif