mirror of https://github.com/minetest/minetest.git
148 lines
3.5 KiB
GLSL
148 lines
3.5 KiB
GLSL
uniform sampler2D baseTexture;
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uniform sampler2D normalTexture;
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uniform sampler2D textureFlags;
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uniform vec4 emissiveColor;
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uniform vec4 skyBgColor;
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uniform float fogDistance;
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uniform vec3 eyePosition;
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varying vec3 vNormal;
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varying vec3 vPosition;
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varying vec3 worldPosition;
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varying vec3 eyeVec;
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varying vec3 lightVec;
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varying float vIDiff;
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bool normalTexturePresent = false;
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bool texTileableHorizontal = false;
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bool texTileableVertical = false;
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bool texSeamless = false;
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const float e = 2.718281828459;
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const float BS = 10.0;
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const float fogStart = FOG_START;
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const float fogShadingParameter = 1 / ( 1 - fogStart);
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#ifdef ENABLE_TONE_MAPPING
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/* Hable's UC2 Tone mapping parameters
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A = 0.22;
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B = 0.30;
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C = 0.10;
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D = 0.20;
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E = 0.01;
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F = 0.30;
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W = 11.2;
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equation used: ((x * (A * x + C * B) + D * E) / (x * (A * x + B) + D * F)) - E / F
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*/
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vec3 uncharted2Tonemap(vec3 x)
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{
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return ((x * (0.22 * x + 0.03) + 0.002) / (x * (0.22 * x + 0.3) + 0.06)) - 0.03333;
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}
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vec4 applyToneMapping(vec4 color)
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{
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color = vec4(pow(color.rgb, vec3(2.2)), color.a);
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const float gamma = 1.6;
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const float exposureBias = 5.5;
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color.rgb = uncharted2Tonemap(exposureBias * color.rgb);
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// Precalculated white_scale from
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//vec3 whiteScale = 1.0 / uncharted2Tonemap(vec3(W));
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vec3 whiteScale = vec3(1.036015346);
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color.rgb *= whiteScale;
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return vec4(pow(color.rgb, vec3(1.0 / gamma)), color.a);
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}
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#endif
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void get_texture_flags()
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{
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vec4 flags = texture2D(textureFlags, vec2(0.0, 0.0));
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if (flags.r > 0.5) {
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normalTexturePresent = true;
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}
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if (flags.g > 0.5) {
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texTileableHorizontal = true;
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}
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if (flags.b > 0.5) {
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texTileableVertical = true;
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}
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if (texTileableHorizontal && texTileableVertical) {
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texSeamless = true;
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}
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}
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vec4 get_normal_map(vec2 uv)
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{
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vec4 bump = texture2D(normalTexture, uv).rgba;
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bump.xyz = normalize(bump.xyz * 2.0 - 1.0);
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return bump;
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}
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void main(void)
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{
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vec3 color;
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vec4 bump;
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vec2 uv = gl_TexCoord[0].st;
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bool use_normalmap = false;
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get_texture_flags();
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#if USE_NORMALMAPS == 1
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if (normalTexturePresent) {
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bump = get_normal_map(uv);
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use_normalmap = true;
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}
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#endif
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vec4 base = texture2D(baseTexture, uv).rgba;
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#ifdef USE_DISCARD
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// If alpha is zero, we can just discard the pixel. This fixes transparency
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// on GPUs like GC7000L, where GL_ALPHA_TEST is not implemented in mesa.
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if (base.a == 0.0) {
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discard;
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}
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#endif
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#ifdef ENABLE_BUMPMAPPING
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if (use_normalmap) {
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vec3 L = normalize(lightVec);
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vec3 E = normalize(eyeVec);
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float specular = pow(clamp(dot(reflect(L, bump.xyz), E), 0.0, 1.0), 1.0);
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float diffuse = dot(-E,bump.xyz);
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color = (diffuse + 0.1 * specular) * base.rgb;
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} else {
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color = base.rgb;
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}
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#else
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color = base.rgb;
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#endif
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vec4 col = vec4(color.rgb, base.a);
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col.rgb *= gl_Color.rgb;
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col.rgb *= emissiveColor.rgb * vIDiff;
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#ifdef ENABLE_TONE_MAPPING
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col = applyToneMapping(col);
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#endif
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// Due to a bug in some (older ?) graphics stacks (possibly in the glsl compiler ?),
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// the fog will only be rendered correctly if the last operation before the
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// clamp() is an addition. Else, the clamp() seems to be ignored.
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// E.g. the following won't work:
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// float clarity = clamp(fogShadingParameter
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// * (fogDistance - length(eyeVec)) / fogDistance), 0.0, 1.0);
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// As additions usually come for free following a multiplication, the new formula
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// should be more efficient as well.
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// Note: clarity = (1 - fogginess)
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float clarity = clamp(fogShadingParameter
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- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
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col = mix(skyBgColor, col, clarity);
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gl_FragColor = vec4(col.rgb, base.a);
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}
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