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authorBrian Paul <brianp@vmware.com>2009-09-10 08:41:12 -0600
committerBrian Paul <brianp@vmware.com>2009-09-10 08:41:12 -0600
commite9ba9ffc9aa5dcc2de02dc3e58279ffda2318c79 (patch)
tree0b6f34cde490295fe35c33efd248acd92275a36b
parent23fefa031f8c6c87a7894247829131293449cb17 (diff)
mesa: in texenvprogram code, only do saturation when really needed.
For some env modes (like modulate or replace) we don't have to clamp because we know the results will be in [0,1].
-rw-r--r--src/mesa/main/texenvprogram.c61
1 files changed, 53 insertions, 8 deletions
diff --git a/src/mesa/main/texenvprogram.c b/src/mesa/main/texenvprogram.c
index 870970a355..2f3e47e69e 100644
--- a/src/mesa/main/texenvprogram.c
+++ b/src/mesa/main/texenvprogram.c
@@ -248,6 +248,40 @@ static GLuint translate_mode( GLenum envMode, GLenum mode )
/**
+ * Do we need to clamp the results of the given texture env/combine mode?
+ * If the inputs to the mode are in [0,1] we don't always have to clamp
+ * the results.
+ */
+static GLboolean
+need_saturate( GLuint mode )
+{
+ switch (mode) {
+ case MODE_REPLACE:
+ case MODE_MODULATE:
+ case MODE_INTERPOLATE:
+ return GL_FALSE;
+ case MODE_ADD:
+ case MODE_ADD_SIGNED:
+ case MODE_SUBTRACT:
+ case MODE_DOT3_RGB:
+ case MODE_DOT3_RGB_EXT:
+ case MODE_DOT3_RGBA:
+ case MODE_DOT3_RGBA_EXT:
+ case MODE_MODULATE_ADD_ATI:
+ case MODE_MODULATE_SIGNED_ADD_ATI:
+ case MODE_MODULATE_SUBTRACT_ATI:
+ case MODE_ADD_PRODUCTS:
+ case MODE_ADD_PRODUCTS_SIGNED:
+ case MODE_BUMP_ENVMAP_ATI:
+ return GL_TRUE;
+ default:
+ assert(0);
+ }
+}
+
+
+
+/**
* Translate TEXTURE_x_BIT to TEXTURE_x_INDEX.
*/
static GLuint translate_tex_src_bit( GLbitfield bit )
@@ -1116,7 +1150,7 @@ static struct ureg
emit_texenv(struct texenv_fragment_program *p, GLuint unit)
{
const struct state_key *key = p->state;
- GLboolean saturate;
+ GLboolean rgb_saturate, alpha_saturate;
GLuint rgb_shift, alpha_shift;
struct ureg out, dest;
@@ -1146,7 +1180,19 @@ emit_texenv(struct texenv_fragment_program *p, GLuint unit)
/* If we'll do rgb/alpha shifting don't saturate in emit_combine().
* We don't want to clamp twice.
*/
- saturate = !(rgb_shift || alpha_shift);
+ if (rgb_shift)
+ rgb_saturate = GL_FALSE; /* saturate after rgb shift */
+ else if (need_saturate(key->unit[unit].ModeRGB))
+ rgb_saturate = GL_TRUE;
+ else
+ rgb_saturate = GL_FALSE;
+
+ if (alpha_shift)
+ alpha_saturate = GL_FALSE; /* saturate after alpha shift */
+ else if (need_saturate(key->unit[unit].ModeA))
+ alpha_saturate = GL_TRUE;
+ else
+ alpha_saturate = GL_FALSE;
/* If this is the very last calculation, emit direct to output reg:
*/
@@ -1162,7 +1208,7 @@ emit_texenv(struct texenv_fragment_program *p, GLuint unit)
*/
if (key->unit[unit].ModeRGB == key->unit[unit].ModeA &&
args_match(key, unit)) {
- out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
+ out = emit_combine( p, dest, WRITEMASK_XYZW, rgb_saturate,
unit,
key->unit[unit].NumArgsRGB,
key->unit[unit].ModeRGB,
@@ -1170,7 +1216,7 @@ emit_texenv(struct texenv_fragment_program *p, GLuint unit)
}
else if (key->unit[unit].ModeRGB == MODE_DOT3_RGBA_EXT ||
key->unit[unit].ModeRGB == MODE_DOT3_RGBA) {
- out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
+ out = emit_combine( p, dest, WRITEMASK_XYZW, rgb_saturate,
unit,
key->unit[unit].NumArgsRGB,
key->unit[unit].ModeRGB,
@@ -1180,12 +1226,12 @@ emit_texenv(struct texenv_fragment_program *p, GLuint unit)
/* Need to do something to stop from re-emitting identical
* argument calculations here:
*/
- out = emit_combine( p, dest, WRITEMASK_XYZ, saturate,
+ out = emit_combine( p, dest, WRITEMASK_XYZ, rgb_saturate,
unit,
key->unit[unit].NumArgsRGB,
key->unit[unit].ModeRGB,
key->unit[unit].OptRGB);
- out = emit_combine( p, dest, WRITEMASK_W, saturate,
+ out = emit_combine( p, dest, WRITEMASK_W, alpha_saturate,
unit,
key->unit[unit].NumArgsA,
key->unit[unit].ModeA,
@@ -1196,8 +1242,7 @@ emit_texenv(struct texenv_fragment_program *p, GLuint unit)
*/
if (alpha_shift || rgb_shift) {
struct ureg shift;
-
- saturate = GL_TRUE; /* always saturate at this point */
+ GLboolean saturate = GL_TRUE; /* always saturate at this point */
if (rgb_shift == alpha_shift) {
shift = register_scalar_const(p, (GLfloat)(1<<rgb_shift));