Fix Intel HD 4000

fuzzie360 · fuzzie360 · commit 3232760e93cd · 2016-03-07T15:53:20.000+08:00
diff --git a/src/backend/mode_gpu.js b/src/backend/mode_gpu.js
@@ -277,18 +277,22 @@
 					'highp float decode32(highp vec4 rgba) {',
 					(endianness == 'LE' ? '' : '	rgba.rgba = rgba.abgr;'),
 					'	rgba *= 255.0;',
-					'	highp float sign = rgba.a > 127.0 ? -1.0 : 1.0;',
-					'	highp float exponent = 2.0 * integerMod(rgba.a, 128.0) + (rgba.b > 127.0 ? 1.0 : 0.0);',
-					'	highp float res;',
-					'	if (abs(exponent) < EPSILON) {',
-					'		res = sign * 0.0;',
+					'	int r = int(rgba.r+0.5);',
+					'	int g = int(rgba.g+0.5);',
+					'	int b = int(rgba.b+0.5);',
+					'	int a = int(rgba.a+0.5);',
+					'	int sign = a > 127 ? -1 : 1;',
+					'	int exponent = 2 * (a > 127 ? a - 128 : a) + (b > 127 ? 1 : 0);',
+					'	float res;',
+					'	if (exponent == 0) {',
+					'		res = float(sign) * 0.0;',
 					'	} else {',
-					'		exponent -= 127.0;',
-					'		res = exp2(exponent);',
-					'		res += integerMod(rgba.b, 128.0) * exp2(exponent-7.0);',
-					'		res += rgba.g * exp2(exponent-15.0);',
-					'		res += rgba.r * exp2(exponent-23.0);',
-					'		res *= sign;',
+					'		exponent -= 127;',
+					'		res = exp2(float(exponent));',
+					'		res += float(b > 127 ? b - 128 : b) * exp2(float(exponent-7));',
+					'		res += float(g) * exp2(float(exponent-15));',
+					'		res += float(r) * exp2(float(exponent-23));',
+					'		res *= float(sign);',
 					'	}',
 					'	return res;',
 					'}',
@@ -306,12 +310,12 @@
 					'	highp float mantissa_part3 = integerMod(F * exp2(7.0-exponent), 128.0);',
 					'	exponent += 127.0;',
 					'	vec4 rgba;',
-					'	rgba.a = 128.0 * sign + floor(exponent/2.0);',
+					'	rgba.a = 128.0 * sign + exponent/2.0;',
 					'	rgba.b = 128.0 * integerMod(exponent, 2.0) + mantissa_part3;',
 					'	rgba.g = mantissa_part2;',
 					'	rgba.r = mantissa_part1;',
 					(endianness == 'LE' ? '' : '	rgba.rgba = rgba.abgr;'),
-					'	rgba /= 255.0;',
+					'	rgba *= 0.003921569;',
 					'	return rgba;',
 					'}',
 					'// Dragons end here',
