minetest/client/shaders/object_shader/opengl_fragment.glsl
hecks fcff9f2911 Remove "generate normal maps" feature ()
Erase all traces of normal "generation" from fragment shaders
Remove the "feature" from the engine and default config
Remove any leftover documentation of it
2020-09-14 19:27:25 +02:00

148 lines
3.5 KiB
GLSL

uniform sampler2D baseTexture;
uniform sampler2D normalTexture;
uniform sampler2D textureFlags;
uniform vec4 emissiveColor;
uniform vec4 skyBgColor;
uniform float fogDistance;
uniform vec3 eyePosition;
varying vec3 vNormal;
varying vec3 vPosition;
varying vec3 worldPosition;
varying vec3 eyeVec;
varying vec3 lightVec;
varying float vIDiff;
bool normalTexturePresent = false;
bool texTileableHorizontal = false;
bool texTileableVertical = false;
bool texSeamless = false;
const float e = 2.718281828459;
const float BS = 10.0;
const float fogStart = FOG_START;
const float fogShadingParameter = 1 / ( 1 - fogStart);
#ifdef ENABLE_TONE_MAPPING
/* Hable's UC2 Tone mapping parameters
A = 0.22;
B = 0.30;
C = 0.10;
D = 0.20;
E = 0.01;
F = 0.30;
W = 11.2;
equation used: ((x * (A * x + C * B) + D * E) / (x * (A * x + B) + D * F)) - E / F
*/
vec3 uncharted2Tonemap(vec3 x)
{
return ((x * (0.22 * x + 0.03) + 0.002) / (x * (0.22 * x + 0.3) + 0.06)) - 0.03333;
}
vec4 applyToneMapping(vec4 color)
{
color = vec4(pow(color.rgb, vec3(2.2)), color.a);
const float gamma = 1.6;
const float exposureBias = 5.5;
color.rgb = uncharted2Tonemap(exposureBias * color.rgb);
// Precalculated white_scale from
//vec3 whiteScale = 1.0 / uncharted2Tonemap(vec3(W));
vec3 whiteScale = vec3(1.036015346);
color.rgb *= whiteScale;
return vec4(pow(color.rgb, vec3(1.0 / gamma)), color.a);
}
#endif
void get_texture_flags()
{
vec4 flags = texture2D(textureFlags, vec2(0.0, 0.0));
if (flags.r > 0.5) {
normalTexturePresent = true;
}
if (flags.g > 0.5) {
texTileableHorizontal = true;
}
if (flags.b > 0.5) {
texTileableVertical = true;
}
if (texTileableHorizontal && texTileableVertical) {
texSeamless = true;
}
}
vec4 get_normal_map(vec2 uv)
{
vec4 bump = texture2D(normalTexture, uv).rgba;
bump.xyz = normalize(bump.xyz * 2.0 - 1.0);
return bump;
}
void main(void)
{
vec3 color;
vec4 bump;
vec2 uv = gl_TexCoord[0].st;
bool use_normalmap = false;
get_texture_flags();
#if USE_NORMALMAPS == 1
if (normalTexturePresent) {
bump = get_normal_map(uv);
use_normalmap = true;
}
#endif
vec4 base = texture2D(baseTexture, uv).rgba;
#ifdef USE_DISCARD
// If alpha is zero, we can just discard the pixel. This fixes transparency
// on GPUs like GC7000L, where GL_ALPHA_TEST is not implemented in mesa.
if (base.a == 0.0) {
discard;
}
#endif
#ifdef ENABLE_BUMPMAPPING
if (use_normalmap) {
vec3 L = normalize(lightVec);
vec3 E = normalize(eyeVec);
float specular = pow(clamp(dot(reflect(L, bump.xyz), E), 0.0, 1.0), 1.0);
float diffuse = dot(-E,bump.xyz);
color = (diffuse + 0.1 * specular) * base.rgb;
} else {
color = base.rgb;
}
#else
color = base.rgb;
#endif
vec4 col = vec4(color.rgb, base.a);
col.rgb *= gl_Color.rgb;
col.rgb *= emissiveColor.rgb * vIDiff;
#ifdef ENABLE_TONE_MAPPING
col = applyToneMapping(col);
#endif
// 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);
}