voxel_engine/shaders/chunk.vert
2023-10-19 12:59:58 +02:00

51 lines
1.3 KiB
GLSL

#version 330 core
layout (location = 0) in ivec3 in_position;
layout (location = 1) in int voxel_id;
layout (location = 2) in int face_id;
layout (location = 3) in int ao_id;
layout (location = 4) in int flip_id;
uniform mat4 m_proj;
uniform mat4 m_view;
uniform mat4 m_model;
out vec3 voxel_color;
out vec2 uv;
out float shading;
const float ao_values[4] = float[4](0.1, 0.25, 0.1, 1.0);
const float face_shading[6] = float[6](
1.0, 0.5, // top bottom
0.5, 0.8, // right left
0.5, 0.8 // front back
);
const vec2 uv_coords[4] = vec2[4](
vec2(0, 0), vec2(0, 1),
vec2(1, 0), vec2(1, 1)
);
const int uv_indices[24] = int[24](
1, 0, 2, 1, 2, 3, // tex coord indices for vertices of an even face
3, 0, 2, 3, 1, 0, // odd face
3, 1, 0, 3, 0, 2, // even flipped face
1, 2, 3, 1, 0, 2 // odd flipped face
);
vec3 hash31(float p) {
vec3 p3 = fract(vec3(p * 21.2) * vec3(0.1031, 0.1030, 0.0973));
p3 += dot(p3, p3.yzx + 33.33);
return fract((p3.xxy + p3.yzz) * p3.zyx) + 0.05;
}
void main() {
int uv_index = gl_VertexID % 6 + ((face_id & 1) + flip_id * 2) * 6;
uv = uv_coords[uv_indices[uv_index]];
voxel_color = hash31(voxel_id);
shading = face_shading[face_id] * ao_values[ao_id];
gl_Position = m_proj * m_view * m_model * vec4(in_position, 1.0);
}