from libs import *
from OpenGL.GL import shaders
import os

VS = f"""
#version 120
{"\n".join([f"attribute {a};" for a in VERTEX_ATTRS])}
{"\n".join([f"varying {a}F;" for a in VERTEX_ATTRS])}
{"\n".join([
    f"uniform {v[1]} {k};" for (k, v) in UNIFORMS.items() if v[0] == "vert"
])}
void main() {{
    gl_Position = MVP * vec4(position, 1.0);
{"\n".join([f"    {a.split()[1]}F = {a.split()[1]};" for a in VERTEX_ATTRS])}
}}
"""

FS = f"""
#version 120
{"\n".join([f"varying {a}F;" for a in VERTEX_ATTRS])}
{"\n".join([
    f"uniform {v[1]} {k};" for (k, v) in UNIFORMS.items() if v[0] == "frag"
])}
void main() {{
    float ambient = reflsF.x;
    vec3 lightDir = normalize(lightPos.xyz - positionF);
    float diffuse = reflsF.y * lightPos.w *
        dot(normalF, lightDir) / pow(distance(lightPos.xyz, positionF), 2);
    float specular = reflsF.z * lightPos.w * pow(max(dot(
        normalize(camPos - positionF), reflect(-lightDir, normalF)
    ), 0.0), reflsF.w);
    gl_FragColor = vec4((ambient + diffuse + specular) * colF.xyz, colF.w);
}}
"""

def init_display():
    pygame.init()
    full = os.environ.get("FULLSCREEN")
    pygame.display.set_mode((640, 480),
        pygame.DOUBLEBUF | pygame.OPENGL |
        (pygame.FULLSCREEN | pygame.SCALED if full else pygame.RESIZABLE),
    vsync=1)
    pygame.event.set_allowed([
        pygame.KEYDOWN, pygame.KEYUP,
        pygame.MOUSEBUTTONDOWN, pygame.MOUSEBUTTONUP, pygame.MOUSEMOTION,
        pygame.QUIT, pygame.WINDOWRESIZED, pygame.WINDOWSIZECHANGED
    ])
    pygame.display.set_caption("Voxels")
    sp = shaders.compileProgram(
        shaders.compileShader(VS, GL_VERTEX_SHADER),
        shaders.compileShader(FS, GL_FRAGMENT_SHADER)
    )
    for (k, v) in UNIFORMS.items():
        v[2] = glGetUniformLocation(sp, k)
    glUseProgram(sp)
    glEnable(GL_DEPTH_TEST)
    glEnable(GL_BLEND)
    glEnable(GL_CULL_FACE)
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
    glClearColor(0.1, 0.1, 0.1, 1.0)