diff options
Diffstat (limited to 'src/mesa/main')
| -rw-r--r-- | src/mesa/main/pack.c | 91 | ||||
| -rw-r--r-- | 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 41485a1bf06..4d4b4a82569 100644 --- a/src/mesa/main/pack.c +++ b/src/mesa/main/pack.c @@ -5250,3 +5250,94 @@ _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 b1853cd5909..cd49c74954a 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 |