Module: Mesa Branch: 8.0 Commit: 8836517250fbe8f98c0082e289178fe4d4e2306b URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=8836517250fbe8f98c0082e289178fe4d4e2306b
Author: Brian Paul <[email protected]> Date: Wed Feb 29 20:55:49 2012 -0700 mesa: add _mesa_rebase_rgba_float/uint() functions These will be used by glReadPixels() and glGetTexImage() to fix issues with reading GL_LUMINANCE and other formats. NOTE: This is a candidate for the 8.0 branch. Reviewed-by: José Fonseca <[email protected]> (cherry picked from commit 774c4027651436451b3486f62b9a8903f29a715b) --- src/mesa/main/pack.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/mesa/main/pack.h | 7 ++++ 2 files changed, 98 insertions(+), 0 deletions(-) diff --git a/src/mesa/main/pack.c b/src/mesa/main/pack.c index ee983f9..4b0ee79 100644 --- a/src/mesa/main/pack.c +++ b/src/mesa/main/pack.c @@ -5254,3 +5254,94 @@ _mesa_unpack_image( GLuint dimensions, } } + + +/** + * If we unpack colors from a luminance surface, we'll get pixel colors + * such as (l, l, l, a). + * When we call _mesa_pack_rgba_span_float(format=GL_LUMINANCE), that + * function will compute L=R+G+B before packing. The net effect is we'll + * accidentally store luminance values = 3*l. + * This function compensates for that by converting (aka rebasing) (l,l,l,a) + * to be (l,0,0,a). + * It's a similar story for other formats such as LUMINANCE_ALPHA, ALPHA + * and INTENSITY. + * + * Finally, we also need to do this when the actual surface format does + * not match the logical surface format. For example, suppose the user + * requests a GL_LUMINANCE texture but the driver stores it as RGBA. + * Again, we'll get pixel values like (l,l,l,a). + */ +void +_mesa_rebase_rgba_float(GLuint n, GLfloat rgba[][4], GLenum baseFormat) +{ + GLuint i; + + switch (baseFormat) { + case GL_ALPHA: + for (i = 0; i < n; i++) { + rgba[i][RCOMP] = 0.0F; + rgba[i][GCOMP] = 0.0F; + rgba[i][BCOMP] = 0.0F; + } + break; + case GL_INTENSITY: + /* fall-through */ + case GL_LUMINANCE: + for (i = 0; i < n; i++) { + rgba[i][GCOMP] = 0.0F; + rgba[i][BCOMP] = 0.0F; + rgba[i][ACOMP] = 1.0F; + } + break; + case GL_LUMINANCE_ALPHA: + for (i = 0; i < n; i++) { + rgba[i][GCOMP] = 0.0F; + rgba[i][BCOMP] = 0.0F; + } + break; + default: + /* no-op */ + ; + } +} + + +/** + * As above, but GLuint components. + */ +void +_mesa_rebase_rgba_uint(GLuint n, GLuint rgba[][4], GLenum baseFormat) +{ + GLuint i; + + switch (baseFormat) { + case GL_ALPHA: + for (i = 0; i < n; i++) { + rgba[i][RCOMP] = 0; + rgba[i][GCOMP] = 0; + rgba[i][BCOMP] = 0; + } + break; + case GL_INTENSITY: + /* fall-through */ + case GL_LUMINANCE: + for (i = 0; i < n; i++) { + rgba[i][GCOMP] = 0; + rgba[i][BCOMP] = 0; + rgba[i][ACOMP] = 1; + } + break; + case GL_LUMINANCE_ALPHA: + for (i = 0; i < n; i++) { + rgba[i][GCOMP] = 0; + rgba[i][BCOMP] = 0; + } + break; + default: + /* no-op */ + ; + } +} + + diff --git a/src/mesa/main/pack.h b/src/mesa/main/pack.h index b1853cd..cd49c74 100644 --- a/src/mesa/main/pack.h +++ b/src/mesa/main/pack.h @@ -149,4 +149,11 @@ _mesa_pack_rgba_span_int(struct gl_context *ctx, GLuint n, GLuint rgba[][4], GLenum dstFormat, GLenum dstType, GLvoid *dstAddr); + +extern void +_mesa_rebase_rgba_float(GLuint n, GLfloat rgba[][4], GLenum baseFormat); + +extern void +_mesa_rebase_rgba_uint(GLuint n, GLuint rgba[][4], GLenum baseFormat); + #endif _______________________________________________ mesa-commit mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-commit
