#load "./shaders/jai/shader_triangle.jai";
#load "./shaders/jai/shader_trixel.jai";
#load "./shaders/jai/shader_sky.jai";
#load "./shaders/jai/shader_trile.jai";

Pipeline_Binding :: struct {
    pipeline : sg_pipeline;
    bind     : sg_bindings;
}

gPipelines : struct {

    // Arbitrary triangle rendering for rendering 2D things on the screen.
    // Used for UI rendering.
    arbtri : Pipeline_Binding;
    
    // Trixel rendering. Used for Trile editor rendering, in-game triles are rendered from
    // generated meshes.
    trixel : Pipeline_Binding;

    // Sky rendering.
    sky    : Pipeline_Binding;

    trile  : Pipeline_Binding;

}

create_pipelines :: () {
    create_arbtri_pipeline();
    create_trixel_pipeline();
    create_trile_pipeline();
    create_sky_pipeline();
}

TRIXEL_SIZE_HALF : float : 1.0/32.0;
TRIXEL_SIZE      : float : 1.0/16.0;

gArbtriMem : [100000*3*9]float;

Position_Color :: struct {
    pos: Vector4;
    col: Vector4;
}

create_trixel_pipeline :: () {
    pipeline: sg_pipeline_desc;
    shader_desc := trixel_shader_desc(sg_query_backend());
    pipeline.shader = sg_make_shader(*shader_desc);
    pipeline.layout.buffers[0].stride = 4*3;
    pipeline.layout.buffers[1].stride = 4*3;
    pipeline.layout.buffers[2].step_func = .PER_INSTANCE;
    
    pipeline.layout.attrs[ATTR_trixel_position] = .{ format = .FLOAT3, buffer_index = 0 };
    pipeline.layout.attrs[ATTR_trixel_normal]   = .{ format = .FLOAT3, buffer_index = 1 };
    pipeline.layout.attrs[ATTR_trixel_inst]     = .{ format = .FLOAT4, buffer_index = 2 };
    pipeline.layout.attrs[ATTR_trixel_inst_col] = .{ format = .FLOAT4, buffer_index = 2 };
    pipeline.index_type = .UINT16;
    pipeline.depth = .{
            write_enabled = true,
            compare = .LESS_EQUAL,
    };

    color_state := sg_color_target_state.{
        pixel_format = .RGBA8,
        blend = .{
            enabled = true,
            src_factor_rgb = .SRC_ALPHA,
            dst_factor_rgb = .ONE_MINUS_SRC_ALPHA
        }
    };


    vertices : [24]Vector3 = .[
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2}
    ];

    normals : [24]Vector3 = .[
        .{0.0, 0.0, 1.0},
        .{0.0, 0.0, 1.0},
        .{0.0, 0.0, 1.0},
        .{0.0, 0.0, 1.0},
        .{0.0, 0.0,-1.0},
        .{0.0, 0.0,-1.0},
        .{0.0, 0.0,-1.0},
        .{0.0, 0.0,-1.0},
        .{0.0, 1.0, 0.0},
        .{0.0, 1.0, 0.0},
        .{0.0, 1.0, 0.0},
        .{0.0, 1.0, 0.0},
        .{0.0,-1.0, 0.0},
        .{0.0,-1.0, 0.0},
        .{0.0,-1.0, 0.0},
        .{0.0,-1.0, 0.0},
        .{1.0, 0.0, 0.0},
        .{1.0, 0.0, 0.0},
        .{1.0, 0.0, 0.0},
        .{1.0, 0.0, 0.0},
        .{-1.0, 0.0, 0.0},
        .{-1.0, 0.0, 0.0},
        .{-1.0, 0.0, 0.0},
        .{-1.0, 0.0, 0.0}
    ];

    k : u16 = 0;
    i : u16 = 0;

    indices : [36]u16;
    
    while i < 36 {
        indices[i] = 4*k;
        indices[i + 1] = 4*k + 1;
        indices[i + 2] = 4*k + 2;
        indices[i + 3] = 4*k;
        indices[i + 4] = 4*k + 2;
        indices[i + 5] = 4*k + 3;
        k += 1;
        i += 6;
    }

    
    pipeline.color_count = 1;
    pipeline.colors[0]   = color_state;

    gPipelines.trixel.pipeline = sg_make_pipeline(*pipeline);
    
    ibuffer         := sg_buffer_desc.{ type = .INDEXBUFFER, data = .{ ptr = indices.data, size = 36 * 2 } };
    vbuffer         := sg_buffer_desc.{ data = .{ ptr = vertices.data, size = 24 * 3 * 4 } };
    nbuffer         := sg_buffer_desc.{ data = .{ ptr = normals.data, size = 24 * 3 * 4 } };
    instance_buffer := sg_buffer_desc.{ usage = .STREAM, size = 4096 * size_of(Position_Color)};

    gPipelines.trixel.bind.index_buffer      = sg_make_buffer(*ibuffer);
    gPipelines.trixel.bind.vertex_buffers[0] = sg_make_buffer(*vbuffer);
    gPipelines.trixel.bind.vertex_buffers[1] = sg_make_buffer(*nbuffer);
    gPipelines.trixel.bind.vertex_buffers[2] = sg_make_buffer(*instance_buffer);
}

create_trile_pipeline :: () {
    pipeline: sg_pipeline_desc;
    shader_desc := trixel_shader_desc(sg_query_backend());
    pipeline.shader = sg_make_shader(*shader_desc);
    pipeline.layout.buffers[0].stride = 4*3;
    pipeline.layout.buffers[1].stride = 4*3;
    
    pipeline.layout.attrs[ATTR_trile_position] = .{ format = .FLOAT3, buffer_index = 0 };
    pipeline.layout.attrs[ATTR_trile_normal]   = .{ format = .FLOAT3, buffer_index = 1 };
    pipeline.depth = .{
            write_enabled = true,
            compare = .LESS_EQUAL,
    };

    color_state := sg_color_target_state.{
        pixel_format = .RGBA8,
        blend = .{
            enabled = true,
            src_factor_rgb = .SRC_ALPHA,
            dst_factor_rgb = .ONE_MINUS_SRC_ALPHA
        }
    };


    pipeline.color_count = 1;
    pipeline.colors[0]   = color_state;

    gPipelines.trile.pipeline = sg_make_pipeline(*pipeline);
}

create_sky_pipeline :: () {
    pipeline: sg_pipeline_desc;
    shader_desc := sky_shader_desc(sg_query_backend());
    pipeline.shader = sg_make_shader(*shader_desc);
    pipeline.layout.buffers[0].stride = 4*3;
    
    pipeline.layout.attrs[ATTR_sky_position] = .{ format = .FLOAT3, buffer_index = 0 };
    pipeline.index_type = .UINT16;
    pipeline.depth = .{
            write_enabled = true,
            compare = .LESS_EQUAL,
    };

    color_state := sg_color_target_state.{
        pixel_format = .RGBA8,
        blend = .{
            enabled = true,
            src_factor_rgb = .SRC_ALPHA,
            dst_factor_rgb = .ONE_MINUS_SRC_ALPHA
        }
    };


    vertices : [24]Vector3 = .[
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, -TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, -TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, TRIXEL_SIZE/2},
        .{-TRIXEL_SIZE/2, TRIXEL_SIZE/2, -TRIXEL_SIZE/2}
    ];

    k : u16 = 0;
    i : u16 = 0;

    indices : [36]u16;
    
    while i < 36 {
        indices[i] = 4*k;
        indices[i + 1] = 4*k + 1;
        indices[i + 2] = 4*k + 2;
        indices[i + 3] = 4*k;
        indices[i + 4] = 4*k + 2;
        indices[i + 5] = 4*k + 3;
        k += 1;
        i += 6;
    }

    
    pipeline.color_count = 1;
    pipeline.colors[0]   = color_state;

    gPipelines.sky.pipeline = sg_make_pipeline(*pipeline);
    
    ibuffer         := sg_buffer_desc.{ type = .INDEXBUFFER, data = .{ ptr = indices.data, size = 36 * 2 } };
    vbuffer         := sg_buffer_desc.{ data = .{ ptr = vertices.data, size = 24 * 3 * 4 } };

    gPipelines.sky.bind.index_buffer      = sg_make_buffer(*ibuffer);
    gPipelines.sky.bind.vertex_buffers[0] = sg_make_buffer(*vbuffer);
}

create_arbtri_pipeline :: () {
    pipeline: sg_pipeline_desc;
    shader_desc := triangle_shader_desc(sg_query_backend());
    pipeline.shader = sg_make_shader(*shader_desc);
    
    pipeline.layout.attrs[ATTR_triangle_position] = .{ format = .FLOAT3 };
    pipeline.layout.attrs[ATTR_triangle_color0]   = .{ format = .FLOAT4 };
    pipeline.layout.attrs[ATTR_triangle_uv]       = .{ format = .FLOAT2 };

    color_state := sg_color_target_state.{
        pixel_format = .RGBA8,
        blend = .{
            enabled = true,
            src_factor_rgb = .SRC_ALPHA,
            dst_factor_rgb = .ONE_MINUS_SRC_ALPHA
        }
    };

    pipeline.color_count = 1;
    pipeline.colors[0] = color_state;

    gPipelines.arbtri.pipeline = sg_make_pipeline(*pipeline);
    
    buffer := sg_buffer_desc.{ usage = .DYNAMIC, size = size_of(type_of(gArbtriMem)) };
    gPipelines.arbtri.bind.vertex_buffers[0] = sg_make_buffer(*buffer);
    gPipelines.arbtri.bind.samplers[0] = sg_make_sampler(*(sg_sampler_desc.{
        wrap_u = .CLAMP_TO_EDGE,
        wrap_v = .CLAMP_TO_EDGE,
        min_filter = .NEAREST,
        mag_filter = .NEAREST,
    }));
}