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authorBrian Paul <[email protected]>2011-12-24 08:54:26 -0700
committerBrian Paul <[email protected]>2011-12-24 08:54:26 -0700
commitf1a2aa5cb338766d7a612b2c82c7ec588ed23d0b (patch)
treebb5d2875ac6fbec384d2d8f2cef52ee5a0c2c3b1 /src
parent488d7fc67d36bc0e5247f5d011e8ad4c2dceb5a7 (diff)
mesa: add _mesa_pack_colormask()
For generating bit-wise colormasks for arbitrary pixel formats. Reviewed-by: José Fonseca <[email protected]>
Diffstat (limited to 'src')
-rw-r--r--src/mesa/main/format_pack.c75
-rw-r--r--src/mesa/main/format_pack.h3
2 files changed, 78 insertions, 0 deletions
diff --git a/src/mesa/main/format_pack.c b/src/mesa/main/format_pack.c
index 390b494c009..840559bac5e 100644
--- a/src/mesa/main/format_pack.c
+++ b/src/mesa/main/format_pack.c
@@ -2494,3 +2494,78 @@ _mesa_pack_uint_24_8_depth_stencil_row(gl_format format, GLuint n,
return;
}
}
+
+
+
+/**
+ * Convert a boolean color mask to a packed color where each channel of
+ * the packed value at dst will be 0 or ~0 depending on the colorMask.
+ */
+void
+_mesa_pack_colormask(gl_format format, const GLubyte colorMask[4], void *dst)
+{
+ GLfloat maskColor[4];
+
+ switch (_mesa_get_format_datatype(format)) {
+ case GL_UNSIGNED_NORMALIZED:
+ /* simple: 1.0 will convert to ~0 in the right bit positions */
+ maskColor[0] = colorMask[0] ? 1.0 : 0.0;
+ maskColor[1] = colorMask[1] ? 1.0 : 0.0;
+ maskColor[2] = colorMask[2] ? 1.0 : 0.0;
+ maskColor[3] = colorMask[3] ? 1.0 : 0.0;
+ _mesa_pack_float_rgba_row(format, 1,
+ (const GLfloat (*)[4]) maskColor, dst);
+ break;
+ case GL_SIGNED_NORMALIZED:
+ case GL_FLOAT:
+ /* These formats are harder because it's hard to know the floating
+ * point values that will convert to ~0 for each color channel's bits.
+ * This solution just generates a non-zero value for each color channel
+ * then fixes up the non-zero values to be ~0.
+ * Note: we'll need to add special case code if we ever have to deal
+ * with formats with unequal color channel sizes, like R11_G11_B10.
+ * We issue a warning below for channel sizes other than 8,16,32.
+ */
+ {
+ GLuint bits = _mesa_get_format_max_bits(format); /* bits per chan */
+ GLuint bytes = _mesa_get_format_bytes(format);
+ GLuint i;
+
+ /* this should put non-zero values into the channels of dst */
+ maskColor[0] = colorMask[0] ? -1.0 : 0.0;
+ maskColor[1] = colorMask[1] ? -1.0 : 0.0;
+ maskColor[2] = colorMask[2] ? -1.0 : 0.0;
+ maskColor[3] = colorMask[3] ? -1.0 : 0.0;
+ _mesa_pack_float_rgba_row(format, 1,
+ (const GLfloat (*)[4]) maskColor, dst);
+
+ /* fix-up the dst channels by converting non-zero values to ~0 */
+ if (bits == 8) {
+ GLubyte *d = (GLubyte *) dst;
+ for (i = 0; i < bytes; i++) {
+ d[i] = d[i] ? 0xffff : 0x0;
+ }
+ }
+ else if (bits == 16) {
+ GLushort *d = (GLushort *) dst;
+ for (i = 0; i < bytes / 2; i++) {
+ d[i] = d[i] ? 0xffff : 0x0;
+ }
+ }
+ else if (bits == 32) {
+ GLuint *d = (GLuint *) dst;
+ for (i = 0; i < bytes / 4; i++) {
+ d[i] = d[i] ? 0xffffffffU : 0x0;
+ }
+ }
+ else {
+ _mesa_problem(NULL, "unexpected size in _mesa_pack_colormask()");
+ return;
+ }
+ }
+ break;
+ default:
+ _mesa_problem(NULL, "unexpected format data type in gen_color_mask()");
+ return;
+ }
+}
diff --git a/src/mesa/main/format_pack.h b/src/mesa/main/format_pack.h
index 7df1356321c..f1b48051065 100644
--- a/src/mesa/main/format_pack.h
+++ b/src/mesa/main/format_pack.h
@@ -95,4 +95,7 @@ _mesa_pack_uint_24_8_depth_stencil_row(gl_format format, GLuint n,
const GLuint *src, void *dst);
+extern void
+_mesa_pack_colormask(gl_format format, const GLubyte colorMask[4], void *dst);
+
#endif