The OpenGL C function glTexImage2D has the following signature:
void glTexImage2D(GLenum target,
GLint level,
GLint internalFormat,
GLsizei width,
GLsizei height,
GLint border,
GLenum format,
GLenum type,
const GLvoid * data);
However, the corresponding Context.TexImage2D method in package gl
does not include the internalFormat parameter, and use the format
argument instead. That's ok for many texture formats; for example,
RGBA textures have both format and internalFormat set to GL_RGBA.
But not always. In particular, OpenGL ES 3 allows the use of sRGB
encoded textures by specifying GL_SRGB8_ALPHA8 as internalFormat,
but keeping GL_RGBA as format.
Add the internalFormat to the Context package. This is unfortunately
a breaking change, but adding a new function ("glTexImage2D2"?) to
Context is too ugly for a parameter that should have been there all
along. (Adding a new method to the Context interface is technically
also a breaking change, but I don't expect that there are any
external implementers of the interface).
Change-Id: I12a45a34f604e51cb1be26aed906025ccfac533a
Reviewed-on: https://go-review.googlesource.com/133155
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
0ff817254b