stk-code_catmod/data/shaders/grass_pass2.frag

50 lines
1.2 KiB
GLSL

#ifdef UBO_DISABLED
uniform mat4 ViewMatrix;
uniform mat4 ProjectionMatrix;
uniform mat4 InverseViewMatrix;
uniform mat4 InverseProjectionMatrix;
#else
layout (std140) uniform MatrixesData
{
mat4 ViewMatrix;
mat4 ProjectionMatrix;
mat4 InverseViewMatrix;
mat4 InverseProjectionMatrix;
mat4 ShadowViewProjMatrixes[4];
vec2 screen;
};
#endif
uniform sampler2D Albedo;
uniform vec3 SunDir;
uniform sampler2D dtex;
in vec3 nor;
in vec2 uv;
out vec4 FragColor;
vec3 getLightFactor(float specMapValue);
void main(void)
{
vec2 texc = gl_FragCoord.xy / screen;
float z = texture(dtex, texc).x;
vec4 xpos = 2.0 * vec4(texc, z, 1.0) - 1.0f;
xpos = InverseProjectionMatrix * xpos;
xpos /= xpos.w;
vec3 eyedir = normalize(xpos.xyz);
// Inspired from http://http.developer.nvidia.com/GPUGems3/gpugems3_ch16.html
float fEdotL = max(0., dot(SunDir, eyedir));
float fPowEdotL = pow(fEdotL, 4.);
float fLdotNBack = max(0., - dot(nor, SunDir) * 0.6 + 0.4);
float scattering = mix(fPowEdotL, fLdotNBack, .5);
vec4 color = texture(Albedo, uv);
if (color.a < 0.5) discard;
vec3 LightFactor = (scattering * 0.3) + getLightFactor(1.);
FragColor = vec4(color.xyz * LightFactor, 1.);
}