Skip to content
Permalink
Browse files

Shaders: Remove unnecessary 'if' statements

Pull if GENERATE_NORMALMAPS == 1 into the template to avoid evaluating
it for each fragment.
Remove if (fogDistance != 0.0).
  • Loading branch information
lhofhansl authored and paramat committed Dec 24, 2016
1 parent a76e769 commit 923a8f1983271f65c80cbbde7c46153ce58560b4
@@ -163,7 +163,8 @@ void main(void)
}
#endif

if (GENERATE_NORMALMAPS == 1 && normalTexturePresent == false) {
#if GENERATE_NORMALMAPS == 1
if (normalTexturePresent == false) {
float tl = get_rgb_height(vec2(uv.x - SAMPLE_STEP, uv.y + SAMPLE_STEP));
float t = get_rgb_height(vec2(uv.x - SAMPLE_STEP, uv.y - SAMPLE_STEP));
float tr = get_rgb_height(vec2(uv.x + SAMPLE_STEP, uv.y + SAMPLE_STEP));
@@ -177,7 +178,7 @@ void main(void)
bump = vec4(normalize(vec3 (dX, dY, NORMALMAPS_STRENGTH)), 1.0);
use_normalmap = true;
}

#endif
vec4 base = texture2D(baseTexture, uv).rgba;

#ifdef ENABLE_BUMPMAPPING
@@ -200,20 +201,18 @@ void main(void)
col = applyToneMapping(col);
#endif

if (fogDistance != 0.0) {
// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
// the fog will only be rendered correctly if the last operation before the
// clamp() is an addition. Else, the clamp() seems to be ignored.
// E.g. the following won't work:
// float clarity = clamp(fogShadingParameter
// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
// As additions usually come for free following a multiplication, the new formula
// should be more efficient as well.
// Note: clarity = (1 - fogginess)
float clarity = clamp(fogShadingParameter
- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
col = mix(skyBgColor, col, clarity);
}
// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
// the fog will only be rendered correctly if the last operation before the
// clamp() is an addition. Else, the clamp() seems to be ignored.
// E.g. the following won't work:
// float clarity = clamp(fogShadingParameter
// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
// As additions usually come for free following a multiplication, the new formula
// should be more efficient as well.
// Note: clarity = (1 - fogginess)
float clarity = clamp(fogShadingParameter
- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
col = mix(skyBgColor, col, clarity);
col = vec4(col.rgb, base.a);

gl_FragColor = col;
@@ -114,7 +114,8 @@ void main(void)
}
#endif

if (GENERATE_NORMALMAPS == 1 && use_normalmap == false) {
#if GENERATE_NORMALMAPS == 1
if (use_normalmap == false) {
float tl = get_rgb_height (vec2(uv.x-SAMPLE_STEP,uv.y+SAMPLE_STEP));
float t = get_rgb_height (vec2(uv.x-SAMPLE_STEP,uv.y-SAMPLE_STEP));
float tr = get_rgb_height (vec2(uv.x+SAMPLE_STEP,uv.y+SAMPLE_STEP));
@@ -128,6 +129,7 @@ void main(void)
bump = vec4 (normalize(vec3 (dX, -dY, NORMALMAPS_STRENGTH)),1.0);
use_normalmap = true;
}
#endif

vec4 base = texture2D(baseTexture, uv).rgba;

@@ -156,20 +158,18 @@ vec4 base = texture2D(baseTexture, uv).rgba;
col = applyToneMapping(col);
#endif

if (fogDistance != 0.0) {
// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
// the fog will only be rendered correctly if the last operation before the
// clamp() is an addition. Else, the clamp() seems to be ignored.
// E.g. the following won't work:
// float clarity = clamp(fogShadingParameter
// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
// As additions usually come for free following a multiplication, the new formula
// should be more efficient as well.
// Note: clarity = (1 - fogginess)
float clarity = clamp(fogShadingParameter
- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
col = mix(skyBgColor, col, clarity);
}
// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
// the fog will only be rendered correctly if the last operation before the
// clamp() is an addition. Else, the clamp() seems to be ignored.
// E.g. the following won't work:
// float clarity = clamp(fogShadingParameter
// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
// As additions usually come for free following a multiplication, the new formula
// should be more efficient as well.
// Note: clarity = (1 - fogginess)
float clarity = clamp(fogShadingParameter
- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
col = mix(skyBgColor, col, clarity);
col = vec4(col.rgb, base.a);

gl_FragColor = col;
@@ -75,7 +75,8 @@ void main(void)
}
#endif

if (GENERATE_NORMALMAPS == 1 && normalTexturePresent == false) {
#if GENERATE_NORMALMAPS == 1
if (normalTexturePresent == false) {
float tl = get_rgb_height(vec2(uv.x - SAMPLE_STEP, uv.y + SAMPLE_STEP));
float t = get_rgb_height(vec2(uv.x - SAMPLE_STEP, uv.y - SAMPLE_STEP));
float tr = get_rgb_height(vec2(uv.x + SAMPLE_STEP, uv.y + SAMPLE_STEP));
@@ -89,6 +90,7 @@ void main(void)
bump = vec4(normalize(vec3 (dX, dY, NORMALMAPS_STRENGTH)), 1.0);
use_normalmap = true;
}
#endif

vec4 base = texture2D(baseTexture, uv).rgba;

@@ -108,19 +110,18 @@ void main(void)

vec4 col = vec4(color.rgb, base.a);
col *= gl_Color;
if (fogDistance != 0.0) {
// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
// the fog will only be rendered correctly if the last operation before the
// clamp() is an addition. Else, the clamp() seems to be ignored.
// E.g. the following won't work:
// float clarity = clamp(fogShadingParameter
// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
// As additions usually come for free following a multiplication, the new formula
// should be more efficient as well.
// Note: clarity = (1 - fogginess)
float clarity = clamp(fogShadingParameter
- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
col = mix(skyBgColor, col, clarity);
}
// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
// the fog will only be rendered correctly if the last operation before the
// clamp() is an addition. Else, the clamp() seems to be ignored.
// E.g. the following won't work:
// float clarity = clamp(fogShadingParameter
// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
// As additions usually come for free following a multiplication, the new formula
// should be more efficient as well.
// Note: clarity = (1 - fogginess)
float clarity = clamp(fogShadingParameter
- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
col = mix(skyBgColor, col, clarity);

gl_FragColor = vec4(col.rgb, base.a);
}

0 comments on commit 923a8f1

Please sign in to comment.